Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Equity Securities Equity Securities [Member] Debt Securities Debt Securities [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value Inputs Level 2 Fair Value, Inputs, Level 2 [Member] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Pension Benefits Pension Plan, Defined Benefit [Member] OPEB Other Postretirement Benefit Plan, Defined Benefit [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Discount rate - assumption Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Defined benefit plan's accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Unfunded pension plans projected benefit obligation Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation Unfunded pension plans accumulated benefit obligations Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation Estimated net loss for defined pension plans amortized from AOCI into net periodic cost Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year Assumed increases in per capita cost of covered health care benefits Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year Ultimate health care cost trend rate Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Pension plan assets target allocation for equity Defined Benefit Plan, Target Plan Asset Allocations Defined Benefit Plan, Actual Plan Asset Allocations Defined Benefit Plan, Actual Plan Asset Allocations Postretirement benefit plan target asset allocation for equity, minimum Defined Benefit Plan, Target Plan Asset Allocations Range Minimum Postretirement benefit plan target asset allocation for equity, maximum Defined Benefit Plan, Target Plan Asset Allocations Range Maximum Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Recognition Period Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Recognition Period Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Recognition Period Assumed rate of return on pension plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets One-percentage point change to rate of return change to net pension (benefit) cost Defined Benefit Plan Effect Of One Percentage Point Change In Assumed Rate Of Return On Plan Assets Effect of a one-percentage-point change in the assumed rate of return on pension plan assets. Trust-owned life insurance fair value Trust Owned Life Insurance Fair Value The fair value of trust-owned life insurance related to postretirement benefit plan assets as of the reporting period. Expected contribution for the next fiscal year Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year Multi-employer benefit plan premiums Multiemployer Plan, Period Contributions Section 401 (k) savings plans matching contributions Section 4 0 1 K Savings Plans Matching Contributions Amount as of the reporting period of employee contributions under Section 401(K) savings plans that the company matches. Other Income and Expenses [Abstract] Royalties from coal Royalty Revenue from Coal Nonoperating depletion and depreciation Nonoperating Depletion And Depreciation Amount of depletion and depreciation associated with nonopertaing assets recorded in "Other income". Subtotal Royalty Income, Nonoperating Rental income Rental Income, Nonoperating Corporate-owned life insurance – net Life Insurance, Corporate or Bank Owned, Change in Value Gains and losses from sale of properties Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Interest income Investment Income, Interest Equity in earnings of Conrail Inc. Income (Loss) from Equity Method Investments Taxes on nonoperating property Taxes, Other Charitable contributions Charitable Contributions Value of contributions made to charitable organizations Other interest expense – net Interest Expense, Other Other Other Income (Expense), Net Other Income (Expense), Net Total Other Nonoperating Income (Expense) Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] 6.21% maturing to 2019 Debt Maturing To Two Thousand Nineteen [Member] Debt Maturing To Two Thousand Nineteen [Member] 6.27% maturing 2020 to 2021 Debt Maturing Two Thousand Twenty To Two Thousand Twenty One [Member] Debt Maturing Two Thousand Twenty And Two Thousand Twenty One [Member] 3.22% maturing 2022 to 2024 Debt Maturing Two Thousand Twenty Two To Two Thousand Twenty Four [Member] Debt Maturing Two Thousand Twenty Two To Two Thousand Twenty Four [Member] 6.92% maturing 2025 to 2037 Debt Maturing Two Thousand Twenty Five To Two Thousand Thirty Seven [Member] Debt Maturing Two Thousand Twenty Five To Two Thousand Thirty One [Member] 4.81% maturing 2041 to 2043 Debt Maturing Two Thousand Forty One To Two Thousand Forty Three [Member] Debt Maturing Two Thousand Thirty Seven To Two Thousand Forty Three [Member] 6.39% maturing 2097 to 2111 Debt Maturing Two Thousand Ninety Seven To Twenty One Thousand Eleven [Member] Debt Maturing Two Thousand Ninety Seven To Twenty One Thousand Eleven [Member] Securitization borrowings, 1.28% Securitization Borrowings [Member] Securitization Borrowings [Member] Other debt, 8.14% maturing to 2024 Other Debt [Member] Other Debt [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Long-term Debt, Weighted Average Interest Rate Long-term Debt, Weighted Average Interest Rate Debt maturing Debt Maturing Value Amount of debt maturing. Securitization borrowings, 1.28% Accounts Receivable Securitization Balance The balance as of the reporting period of the amount owed by the reporting entity to counterparties in securitized loan transactions. Other debt, 8.14% maturing to 2024 Other Long-term Debt Discounts and premiums, net Debt Instrument, Unamortized Discount (Premium), Net Total debt Debt, Long-term and Short-term, Combined Amount Less current maturities and short-term debt Long-Term Debt Capital Lease Obligations And Short-Term Debt, Current Obligation related to long-term debt (excluding convertible debt), capital leases and short-term debt, the portion which is due in one year or less in the future. 2016 Long-term Debt, Maturities, Repayments of Principal in Year Two 2017 Long-term Debt, Maturities, Repayments of Principal in Year Three 2018 Long-term Debt, Maturities, Repayments of Principal in Year Four 2019 Long-term Debt, Maturities, Repayments of Principal in Year Five 2020 and subsequent years Long-term Debt, Maturities, Repayments of Principal after Year Five Long-term debt Long-term Debt and Capital Lease Obligations Equity [Abstract] Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Other Comprehensive Income (Loss) Of Equity Investees Schedule Of Other Comprehensive Income (Loss) [Table Text Block] Schedule Of Other Comprehensive Income (Loss) [Table Text Block] Income Tax Disclosure [Abstract] Prepaid Taxes Prepaid Taxes Change in valuation allowance Valuation Allowance, Deferred Tax Asset, Change in Amount Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized tax benefits, period decrease Unrecognized Tax Benefits, Period Increase (Decrease) Interest expense (income) related to unrecognized tax benefits Unrecognized Tax Benefits, Interest on Income Taxes Expense Interest accrued related to unrecognized tax benefits Unrecognized Tax Benefits, Interest on Income Taxes Accrued One-percentage point increase change in total service and interest cost components Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components One-percentage point decrease change total service and interest cost components Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components One-percentage point increase change in postretirement benefit obligations Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation One-percentage point decrease change in postretirement benefit obligations Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Reconciliation of net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation Depreciation Deferred income taxes Deferred Income Tax Expense (Benefit) Gains and losses on properties and investments Gain (Loss) on Disposition of Assets Changes in assets and liabilities affecting operations: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Materials and supplies Increase (Decrease) in Materials and Supplies Other current assets Increase (Decrease) in Other Current Assets Current liabilities other than debt Increase (Decrease) in Other Operating Liabilities Other – net Other Operating Activities, Cash Flow Statement Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Property additions Payments to Acquire Property, Plant, and Equipment Property sales and other transactions Proceeds from Sale of Property, Plant, and Equipment Investments, including short-term Payments to Acquire Investments Investment sales and other transactions Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Dividends Payments of Ordinary Dividends, Common Stock Common Stock issued Proceeds From Stock Options Exercised Including Tax Benefit Proceeds From Stock Options Exercised, Including Tax Benefit. Purchase and retirement of Common Stock Payments for Repurchase of Common Stock Proceeds from borrowings – net Proceeds from Debt, Net of Issuance Costs Debt repayments Repayments of Debt and Capital Lease Obligations Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents: Cash and Cash Equivalents, at Carrying Value [Abstract] At beginning of year Cash and Cash Equivalents, at Carrying Value At end of year Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Interest (net of amounts capitalized) Interest Paid, Net Income taxes (net of refunds) Income Taxes Paid, Net Payables and Accruals [Abstract] Current Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Earnings Per Share, Basic E P S Basic [Member] The amount of earnings for the period available to each share of common stock outstanding during the reporting period. Earnings Per Share, Diluted E P S Diluted [Member] Earnings (net income) per diluted share. Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items] Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items] [Line Items] for Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Net income Dividend equivalent payments, Basic & Diluted Employee Stock Ownership Plan (ESOP), Dividends Paid to ESOP Income available to common stockholder's, Basic Net Income (Loss) Available to Common Stockholders, Basic Income available to common stockholder's, Diluted Net Income (Loss) Available to Common Stockholders, Diluted Weighted-average shares outstanding, Basic Weighted Average Number of Shares Outstanding, Basic Dilutive effect of outstanding options and share-settled awards Weighted Average Number Diluted Shares Outstanding Adjustment Adjusted weighted-average shares outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted Earnings Per Share, Basic Earnings Per Share, Basic Earnings Per Share, Diluted Earnings Per Share, Diluted Options With Exercise Prices Above Average Market Price Options With Exercise Prices Above Average Market Price Number of options having exercise prices exceeding the average market price of Common Stock. Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] Pensions and other postretirement liabilities, beginning of the year Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Pensions and other post retirement liabilities, net gain (loss) Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Pensions and other postretirement liabilities, reclassification adjustments Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax Pensions and other postretirement liabilities, end of year Other comprehensive gain (loss) of equity investments, beginning of period Other Comprehensive Income Loss Of Equity Investees Net Of Tax Other Comprehensive Income Loss Of Equity Investees Net Of Tax Other comprehensive gain (loss) of equity investments, net gain (loss) Other Comprehensive Income Loss Of Equity Investees Net Gain Loss Other Comprehensive Income Loss Of Equity Investees Net Gain Loss Other comprehensive gain (loss) of equity investments, end of period Accumulated other comprehensive loss, beginning of period Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss, net gain (loss) Accumulated Other Comprehensive Income Loss Net Gain Loss Accumulated Other Comprehensive Income Loss Net Gain Loss Accumulated other comprehensive loss, reclassification adjustments Accumulated Other Comprehensive Income (Loss) Reclassification Adjustments Accumulated other comprehensive gain (loss) reclassifications adjustments. Accumulated other comprehensive loss period end, end of period Accounting Policies [Abstract] Description of Business Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Allowance For Doubtful Accounts Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block] Materials And Supplies Inventory, Policy [Policy Text Block] Investments Investment, Policy [Policy Text Block] Properties Property, Plant and Equipment, Policy [Policy Text Block] Required Accounting Changes New Accounting Pronouncements, Policy [Policy Text Block] Stock Repurchase Program [Abstract] Stock Repurchase Program Treasury Stock [Text Block] Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Rail and other track material Railroad Transportation Equipment [Member] Ties Ties [Member] Value of ties held for productive use. Ballast Ballast [Member] Amount represents ballast held for productive use. Construction in process Construction In Process Roadway [Member] Construction in Process Roadway [Member] Other roadway Other Roadway [Member] Value of other roadway assets held for productive use Total roadway Total Roadway [Member] Value of total roadway assets held for productive use. Locomotives Locomotives [Member] Value of locomotives held for productive use. Freight cars Freight Cars [Member] Value of freight cars held for productive use. Computers and software Technology Equipment [Member] Construction in process Construction In Process Equipment [Member] This element is used to disclose construction in process related to equipment held for productive use. Other equipment Other Machinery and Equipment [Member] Total equipment Equipment [Member] Other property Other Property [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Cost Property, Plant and Equipment, Gross Accumulated Depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Net Book Value Property, Plant and Equipment, Net Depreciation Rate Depreciation Rate Represents the rate of depreciation applied to a particular asset class Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Quarterly Financial Information Disclosure [Abstract] Railway operating revenues Revenues Income from railway operations Operating Income (Loss) Earnings Per Share, Basic Earnings Per Share, Diluted 2015 Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months 2016 Defined Benefit Plan, Expected Future Benefit Payments, Year Two 2017 Defined Benefit Plan, Expected Future Benefit Payments, Year Three 2018 Defined Benefit Plan, Expected Future Benefit Payments, Year Four 2019 Defined Benefit Plan, Expected Future Benefit Payments, Year Five Years 2020 - 2024 Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Total current taxes Current Income Tax Expense (Benefit) Deferred: Deferred Tax Assets, Tax Deferred Expense [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Total deferred taxes Provision for income taxes Income Tax Expense (Benefit) Investments [Abstract] Schedule of Investments [Table] Schedule of Investments [Table] Summary of Investments, Other than Investments in Related Parties, by Type [Axis] Summary of Investments, Other than Investments in Related Parties, by Type [Axis] Summary of Investments, by Type [Domain] Summary of Investments, by Type [Domain] Commercial paper, 2 months Commercial Paper [Member] Federal government bonds, held-to-maturity, 3 months US Treasury Bond Securities [Member] Eligible Item or Group for Fair Value Option [Axis] Eligible Item or Group for Fair Value Option [Axis] Fair Value, Option, Eligible Item or Group [Domain] Fair Value, Option, Eligible Item or Group [Domain] Conrail Inc. Conrail Inc [Member] Jointly owned LLC between NS and CSX that is treated by NS as an equity method investee TTX Company T T X Company [Member] TTX Company [Member] Meridian Speedway LLC Meridian Speedway Llc [Member] Meridian Speedway LLC [Member] Pan Am Southern LLC Pan Am Southern Llc [Member] Pan Am Southern LLC [Member] Other Other Long-term Investments [Member] Schedule of Investments [Line Items] Schedule of Investments [Line Items] Held-to-maturity securities Held-to-maturity Securities Total short-term investments Short-term Investments Equity Method Investments Equity Method Investments Company-owned life insurance at net cash surrender value Cash Surrender Value of Life Insurance Other investments Other Investments Total long-term investments Long-term Investments Held To Maturity Commercial Paper Maturity Date Held To Maturity Commercial Paper Maturity Date The average maturity date in months of held to maturity commercial paper. Average federal government bonds held-to-maturity, months Held To Maturity Federal Government Bond Maturity Date The average maturity date in months of held-to-maturity federal government bonds. Quarterly Financial Data Schedule of Quarterly Financial Information [Table Text Block] Investments Investment [Table Text Block] Statement of Financial Position [Abstract] Properties, accumulated depreciation Common stock, par or stated value per share Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares outstanding, net of treasury shares Common Stock, Shares, Outstanding Funded Status Funded Status [Member] Status of the company's defined pension benefits Other Postretirement Benefits Funded Status Other Postretirement Benefits Funded Status [Member] Other Postretirement Benefits Funded Status Return on assets in plans - assumption Future salary increases - assumption Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Health care trend rate Defined Benefit Plan Assumed Health Care Cost Trend Rate Defined Benefit Plan Assumed Health Care Cost Trend Rate Domestic equity securities Pension Plan Asset Allocation Domestic Equity Securities This element is used to disclose the percentage of allocation of pension plan assets to domestic equity securities. Debt securities Pension Plan Asset Allocation Debt Securities This element is used to disclose the percentage of allocation of pension plan assets to debt securities. International equity securities Pension Plan Asset Allocation International Equity Securities This element is used to disclose the percentage of allocation of pension plan assets to international equity securities. Cash and cash equivalents Pension Plan Asset Allocation Cash And Cash Equivalents This element is used to disclose the percentage allocation of pension plan assets to cash and cash equivalents. Total Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Income (Loss) [Member] Retained Income Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Beginning Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Total comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Dividends on Common Stock ($1.94, $2.04 and $2.22 for years ended 2012, 2013 and 2014, respectively) Dividends, Common Stock, Cash Share repurchases Stock Repurchased and Retired During Period, Value Stock-based compensation, including tax benefit ($42, $38 and $37 for years ended 2012, 2013 and 2014, respectively) Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Other Stockholders' Equity, Other Ending Balance Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies Commitments and Contingencies Disclosure [Text Block] Other Liabilities Disclosure [Abstract] Other Liabilities Other Liabilities [Table Text Block] Provisions For Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Reconciliation Of Statutory Rate To Effective Rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule Of Deferred Tax Assets And Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Reconciliation Of Unrecognized Tax Benefits Summary of Income Tax Contingencies [Table Text Block] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of net losses Defined Benefit Plan, Future Amortization of Gain (Loss) Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Net cost Defined Benefit Plan, Net Periodic Benefit Cost Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Performance Share Units (PSUs) Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Schedule Of Assumptions Used For LTIP And TSOP Grants Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule Of Stock Option Activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary Of Stock Options Exercised Schedule of Cash Proceeds Received from Share-based Payment Awards [Table Text Block] Schedule Of Other Share Activity Schedule of Share-based Compensation, Activity [Table Text Block] Schedule Of Stock Available For Future Grants Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Ltip Employee Stock Option [Member] TSOP Tsop [Member] Norfolk Southern Corporation Thoroughbred Stock Option Plan [Member]. LTIP And TSOP Ltip And Tsop [Member] Incentive award plans for employees (Long-term Incentive Plan and Thoroughbred Stock Option Plan) Expected volatility rate, minimum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Expected volatility rate, maximum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Average expected volatility rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate Average risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Average expected option term, in years Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Option per share grant-date fair value Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period Grant Date Fair Value The grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Income Taxes Income Tax Disclosure [Text Block] Receivables securitization facility - total to be borrowed Accounts Receivable Securitization Total Facility Total amount available under the Accounts Receivable Securitization Facility. Proceeds from Short-term Debt Proceeds from Short-term Debt Repayments of short-term debt Repayments of Short-term Debt Accounts receivable securitization balance Average variable interest rate Short-term Debt, Weighted Average Interest Rate Intent to refinance Intent To Refinance The amount the company intends to refinance under the accounts receivable securitization program. Credit agreement Credit Agreement Amount as of the balance sheet date that the company has the ability to borrow at prevailing rates through a credit agreement. Short-term Debt Short-term Debt Account Receivable Securitization Facility Term Years Account Receivable Securitization Facility Term Years The term, in years, of the Accounts Receivable Securitization Facility. Collateral for securitization borrowings Transfers Accounted for as Secured Borrowings, Assets, Carrying Amount Authority to issue debt/equity securities Authority To Issue Debt Equity Securities The authority the Company has from the Board of Directors to issue additional debt or equity securities through public or private sale. Credit agreement term, years Credit Agreement Term Years The term of the credit agreement the company has in place. Credit agreement due date, year Credit Agreement, Due Date Year Credit Agreement, Due Date Year Performance Share Units (PSUs) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Balance at December 31, 2013 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Performance share units earned - paid in Common Stock Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Earned And Paid In Common Stock Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Earned And Paid In Common Stock Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Unearned Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Unearned Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Unearned Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Balance at December 31, 2014 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Weighted-average grant-date fair value at December 31, 2013 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted-average grant-date fair value of shares granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted-average grant-date fair value of shares vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted-average grant-date fair value of shares earned - paid in Common Stock Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Earned And Paid In Common Stock, Weighted Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Earned And Paid In Common Stock, Weighted Average Grant Date Fair Value Weighted-average grant-date fair value of shares unearned Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Unearned, Weighted Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Unearned, Weighted Average Grant Date Fair Value Weighted-average grant-date fair value of shares forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted-average grant-date fair value at December 31, 2014 Debt With Interest Rates And Maturities Schedule of Maturities of Long-term Debt [Table Text Block] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Stock options outstanding at December 31, 2013 Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Stock options granted Stock options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock options forfeited Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Stock options outstanding at December 31, 2014 Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Weighted average exercise price of stock options outstanding at December 31, 2013 Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted average exercise price of stock options granted Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Weighted average exercise price of stock options exercised Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Weighted average exercise price of stock options forfeited Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Weighted average exercise price of stock options outstanding at December 31, 2014 Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Properties Property, Plant and Equipment Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value Fair Value, Measurement Inputs, Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Inputs Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Long-term investments, fair value Summary of Investments, Other than Investments in Related Parties, Fair Value Long-term debt, including current maturities, fair value Debt Instrument, Fair Value Disclosure Treasury Stock, Number of Shares Held Treasury Stock, Number of Shares Held Treasury Stock, Value Treasury Stock, Value Assets Assets [Abstract] Cash and cash equivalents Short-term investments Accounts receivable – net Accounts Receivable, Net, Current Materials and supplies Materials and supplies Aggregate carrying amount, as of the balance sheet date, of unapplied materials and supplies to be used in the performance or support of carrier operations. Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Current Other current assets Other Assets, Current Total current assets Assets, Current Investments Properties less accumulated depreciation of $10,814 and $10,387 respectively Other assets Other Assets, Noncurrent Total assets Assets Liabilities and stockholdersʼ equity Liabilities and Equity [Abstract] Accounts payable Accounts Payable, Current Short-term debt Income and other taxes Taxes Payable, Current Other current liabilities Other Liabilities, Current Current maturities of long-term debt Long-term Debt and Capital Lease Obligations, Current Total current liabilities Liabilities, Current Long-term debt Other liabilities Other Liabilities, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Total liabilities Liabilities Stockholdersʼ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock $1.00 per share par value, 1,350,000,000 shares authorized; outstanding 308,240,130 and 308,878,402 shares, respectively, net of treasury shares Common Stock, Value, Outstanding Additional paid-in capital Additional Paid in Capital Accumulated other comprehensive loss Retained income Retained Earnings (Accumulated Deficit) Total stockholdersʼ equity Total liabilities and stockholdersʼ equity Liabilities and Equity Income Statement [Abstract] Railway operating revenues Railway operating expenses: Operating Expenses [Abstract] Compensation and benefits Labor and Related Expense Purchased services and rents Purchased services and rents The amount of expense for contract services provided to the Company and rent paid for freight cars owned by other railroads or private companies net of rents received, including lease expenses, primarily for locomotives, railcars, containers, and trailers. Fuel Fuel Costs Depreciation Cost of Services, Depreciation Materials and other Materials and other Materials and other operating expenses not separately disclosed. This element is used when other, more specific, elements are not appropriate. Total railway operating expenses Operating Expenses Income from railway operations Other income – net Interest expense on debt Interest Expense Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Provision for income taxes Net income Per share amounts: Properties Property, Plant and Equipment [Table Text Block] Quarterly Financial Data Quarterly Financial Information [Text Block] Accounts and wages payable Accounts Payable and Accrued Liabilities, Current Casualty and other claims (Note 16) Casualty And Other Claims Current Amount of obligations incurred and payable related to casualty and other claims. Vacation liability Accrued Vacation, Current Due to Conrail (Note 5) Due To Conrail Amount recorded in accounts payable due to Conrail for the operation of the Shared Assets Area. Other Accounts Payable, Other, Current Total Interest payable Interest Payable, Current Postretirement and pension benefit obligations (Note 11) Retiree Benefit Obligations Amount recorded as of the balance sheet date associated with retiree benefit obligations. Other Other Accrued Liabilities, Current Total Deferred tax assets: Deferred Tax Assets, Net [Abstract] Compensation and benefits, including postretirement Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Accruals, including casualty and other claims Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals Other Deferred Tax Assets, Other Total gross deferred tax assets Deferred Tax Assets, Gross Less valuation allowance Deferred Tax Assets, Valuation Allowance Net deferred tax asset Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Deferred tax liabilities: Deferred Tax Liabilities, Net [Abstract] Property Deferred Tax Liabilities, Property, Plant and Equipment Other Deferred Tax Liabilities, Other Total gross deferred tax liabilities Deferred Tax Liabilities, Net Net deferred tax liability Deferred Tax Assets, Net, Noncurrent Net current deferred tax asset Net long-term deferred tax liability Other Liabilities Other Liabilities Disclosure [Text Block] Federal income tax at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount State income taxes, net of federal tax effect Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Internal Revenue Service (IRS) audit, settlement Effective Income Tax Rate Reconciliation, Tax Settlement, Domestic, Amount State tax law changes, net of federal tax effect Effective Income Tax Rate Reconciliation, Tax Settlement, State and Local, Amount Other, net Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount Federal income tax at statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State income taxes, net of Federal tax effect Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Internal Revenue Service audit, settlement Effective Income Tax Rate Reconciliation, Tax Settlement, Domestic, Percent State tax law changes, net of federal tax effect Effective Income Tax Rate Reconciliation, Tax Settlement, State and Local, Percent Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Provision for income taxes Effective Income Tax Rate Reconciliation, Percent Railway Property Recorded Pursuant To Capital Leases Railway Property Recorded Pursuant To Capital Leases Amount as of the balance sheet date of railway property assets recorded pursuant to capital leases. Accumulated Depreciation Associated With Railway Property Recorded Pursuant To Capital Leases Accumulated Depreciation Associated With Railway Property Recorded Pursuant To Capital Leases Amount of accumulated depreciation as of the balance sheet date associated with railway property assets recorded pursuant to capital leases. Costs Of Obtaining Rights To Natural Resources Costs Of Obtaining Rights To Natural Resources Amount as of the balance sheet date included in "other property" related to the costs of obtaining rights to natural resources. Accumulated Depreciation Associated With Costs Of Obtaining Rights To Natural Resources Accumulated Depreciation Associated With Costs Of Obtaining Rights To Natural Resources The amount of accumulated depreciation as of the balance sheet date associated with costs of obtaining rights to natural resources. Interest Costs Incurred Interest Costs Incurred Interest Costs Capitalized Interest Costs Capitalized Environmental liability Accrual for Environmental Loss Contingencies Current environmental liability Accrual for Environmental Loss Contingencies, Undiscounted, Due in Next Twelve Months Known cleanup and remediation locations and projects Environmental Cleanup Locations Number of known locations and projects of environmental loss contingencies. Number of sites - representative sample Environmental Locations Representative Sample A representative sample of the total number of environmental locations and projects. Liability associated with those sites Environmental Locations Representative Sample Liability Liability associated with the representative sample of environmental locations and projects. Environmental locations representative sample liability payout period, in years Environmental Locations Representative Sample Liability Period Number of years over which environmental liabilities are expected to be paid out. Responsible locations with another party Environmental Responsible Party In Conjunction With Other Parties Number of locations the company or its subsidiaries in conjunction with other parties have been identified as potentially responsible parties by the Environmental Protection Agency (EPA). Self-insured injury/damage to third party - up to Self Insured For Bodily Injury And Property Damage To Third Parties Up To Amount up to which the company is self-insured per occurrence for bodily injury and property damage to third parties. Self-insured injury/damage to third parties - and above, per occurrence Self Insured For Bodily Injury And Property Damage To Third Parties Above Amount above which the company is self-insured per occurrence for bodily injury and property damage to third parties. Self-insured NS owned property - up to Self-Insured For Property Owned Up To Amount up to which the company is self-insured, per occurrence, for property owned or in the care, custody or control of the company. Self-insured NS owned property - and above, per occurrence Self-Insured For Property Owned Above Amount above which the company is self-insured, per occurrence, for property owned or in the care, custody or control of the company. Purchase commitments, long-term service contracts Long-term Purchase Commitment, Amount Liable Guarantors Of Indebtedness Liable Guarantors Of Indebtedness Amount as of the balance sheet date in which certain of the company's subsidiaries are contingently liable as guarantors with respect to indebtedness due in 2019 of the Terminal Railroad Association of St. Louis. Four other railroads are jointly and severally liable as guarantors. Long-term investments, carrying value Summary of Investments, Other than Investments in Related Parties, Carrying Amount Long-term debt, including current maturities, carrying value Long-term Debt Investments Investment Holdings [Text Block] Leases [Abstract] 2015 - Operating Leases Operating Leases, Future Minimum Payments Due, Next Twelve Months 2016 - Operating Leases Operating Leases, Future Minimum Payments, Due in Two Years 2017 - Operating Leases Operating Leases, Future Minimum Payments, Due in Three Years 2018 - Operating Leases Operating Leases, Future Minimum Payments, Due in Four Years 2019 - Operating Leases Operating Leases, Future Minimum Payments, Due in Five Years 2020 and subsequent years Operating Leases, Future Minimum Payments, Due Thereafter Total - Operating Leases Operating Leases, Future Minimum Payments Due 2015 - Capital Leases Capital Leases, Future Minimum Payments Due, Next Twelve Months 2016 - Capital Leases Capital Leases, Future Minimum Payments Due in Two Years 2017 - Capital Leases Capital Leases, Future Minimum Payments Due in Three Years 2018 - Capital Leases Capital Leases, Future Minimum Payments Due in Four Years 2019 - Capital Leases Capital Leases, Future Minimum Payments Due in Five Years 2020 and subsequent years - Capital Leases Capital Leases, Future Minimum Payments Due Thereafter Total - Capital Leases Capital Leases, Future Minimum Payments Due Imputed interest on capital leases Imputed Interest On Capital Leases This element is used to disclose the imputed interest on capital lease at a calculated average rate. Present value of minimum lease payments - capital leases Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Average rate of imputed interest on capital leases Average Rate Of Imputed Interest On Capital Leases The average rate by which imputed interest is calculated on capital leases. Operating lease expense - minimum rents Operating Leases, Rent Expense, Minimum Rentals Operating lease expense - contingent rents Contingent Rents This element represents the payments that result from changes occurring after the inception of the lease in the factors (other than passage of time) on which lease payments are based. Primarily comprised of usage-based rent paid to other railroads for joint facility operations. Total operating lease expense Operating Leases, Rent Expense Valuation and Qualifying Accounts [Abstract] Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Valuation Allowance (Included Net In Deferred Tax Liability) For Deferred Tax Assets Valuation Allowance of Deferred Tax Assets [Member] Casualty And Other Claims Included In Other Liabilities Other Liabilities Casualty And Other Claims [Member] Other Liabilities Casualty And Other Claims Current Portion Of Casualty And Other Claims Included In Accounts Payable Accounts Payable Casualty And Other Claims Current [Member] Accounts Payable Casualty And Other Claims Current Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Movement in Valuation Allowances and Reserves [Roll Forward] Movement in Valuation Allowances and Reserves [Roll Forward] Beginning Balance Valuation Allowances and Reserves, Balance Expenses Valuation Allowances and Reserves, Charged to Cost and Expense Other Accounts Valuation Allowances and Reserves, Charged to Other Accounts Deductions Valuation Allowances and Reserves, Deductions Ending Balance Schedule Of Earnings Per Share Calculation Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Summary Of Significant Accounting Policies Significant Accounting Policies [Text Block] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at beginning of year Unrecognized Tax Benefits Additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Additions for tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Reductions for tax positions of prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Settlements with taxing authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Lapse of statutes of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Balance at end of year Future Minimum Lease Payments Future Minimum Lease Payments Table [Text Block] Total amount of future contractually required payments on leases defined as operating and capital. Operating Lease Expense Schedule of Rent Expense [Table Text Block] Common Stock, Dividends, Per Share, Declared Common Stock, Dividends, Per Share, Declared Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Performance Performance [Member] Performance [Member] Market Condition Market Condition [Member] The grant date fair value of performance share units based on a market condition: achievement of a total shareholder return target measured using a Monte Carlo simulation model. Maximum number of shares available for grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Amended LTIP plan-award granted as an option or stock appreciation right Amended LTIP Plan Award Granted As Option Or Stock Appreciation Right Amended LTIP Plan Award Granted As Option Or Stock Appreciation Right Amended LTIP plan - award granted in a form other than option or stock appreciation right Amended LTIP Plan Award Granted As Other Than Option Or Stock Appreciation Right Amended LTIP Plan Award Granted As Other Than Option Or Stock Appreciation Right Compensation costs Allocated Share-based Compensation Expense Tax benefits associated with compensation costs Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Excess tax benefits recognized for share-based awards Excess Tax Benefit from Share-based Compensation, Financing Activities Grant price of options granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value LTIP dividend equivalent payment, in years LTIP Dividend Equivalent Payment Years Number of years holders of LTIP options who remain actively employed, are eligible for dividend equivalent payments on a particular stock option grant. Dividend yield for period dividend equivalents paid Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate When Dividend Equivalents Are Paid Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate When Dividend Equivalents Are Paid. Dividend yield for period dividend equivalents not paid Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate When Dividend Equivalents Are Not Paid The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term where no dividend equivalent payments are made. Aggregate intrinsic value of options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Weighted average remaining contractual term of options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Number of shares exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Aggregate intrinsic value of options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Exercisable weighted average exercise price Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted average remaining contractual term of options exercisable Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term Unrecognized compensation related to stock options granted Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Unrecognized compensation, weighted average period of recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Units other than stock options granted Grant-date fair value of units granted Restriction period, in years Restricted Stock Unit Restriction Period Period of time over which an employee's restricted stock unit award is earned. Restricted Stock Units Paid In Stock Restricted Stock Units Paid In Stock The number of restricted stock units paid out in stock during the period related to Restricted Stock Unit awards, net of any forfeits. Shares issued net of withholding taxes Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Shares Issued Net Of Withholding Taxes Documents the compensation other than options issued net of withholding taxes. Excess tax benefit/expense realized Excess Tax Benefit from Share-based Compensation, Equity Instruments Other than Options, Amount Realized Excess Tax Benefit from Share-based Compensation, Equity Instruments Other than Options, Amount Realized Vesting Period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Performance Share Units Paid Performance Share Units Paid The number of PSUs paid out in Common Stock, net of any forfeits and unearned awards. Current Liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Operating Activities Operating Activities [Axis] Segment, Operating Activities [Domain] Operating Activities [Domain] Intermodal Railway Operating Revenues Market Group Intermodal [Member] Railway Operating Revenues, Market Group, Intermodal Coal Railway Operating Revenues Market Group Coal [Member] Railway Operating Revenues, Market Group, Coal Chemicals Railway Operating Revenues Market Group Chemicals [Member] Railway Operating Revenues, Market Group, Chemicals Metals/Construction Railway Operating Revenues Market Group Metals Construction [Member] Railway Operating Revenues, Market Group, Metals/Construction Agriculture/Consumer Products/Government Railway Operating Revenues Market Group Agriculture Consumer Products Government [Member] Railway Operating Revenues, Market Group, Agriculture/Consumer Products/Government Automotive Railway Operating Revenues Market Group Automotive [Member] Railway Operating Revenues, Market Group, Automotive Paper/Clay/Forest Products Railway Operating Revenues Market Group Paper Clay Forest Products [Member] Railway Operating Revenues, Market Group, Paper/Clay/Forest Products Roadway Roadway [Member] Disclosures over those assets included in our Roadway asset class. Examples include rail, track material, ties, ballast, etc. Equipment Number Of Depreciable Asset Classes Used Range Low End Number Of Depreciable Asset Classes Used Range Low End Number Of Depreciable Asset Classes Used Range Low End Depreciation Studies, Period Depreciation Studies, Period Depreciation Studies, Period Operating route miles Operating Route Miles Approximate number of route miles operated by the company in the East and Midwest. Market groups percent of total railway operating revenues Market Groups Percent Of Total Railway Operating Revenues Percent of total railway operating revenues by market group. Employees covered by collective bargaining agreements Employees Covered By Collective Bargaining Agreements Percent of the company's employees covered by collective bargaining agreements with various labor unions. Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable Depreciation studies description Depreciation Studies Description Explanation of how often depreciation studies are conducted Depreciation rate range minimum Depreciation Rate Range Minimum Depreciation Rate Range Minimum Depreciation rate range maximum Depreciation Rate Range Maximum Depreciation Rate Range Maximum Options exercised Total intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Cash received upon exercise Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options Related tax benefits realized Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options Stock repurchased and retired during period, shares Stock Repurchased and Retired During Period, Shares Stock repurchased and retired during period, cost New stock repurchase program New stock repurchase program Additional number of shares authorized under the new stock repurchase program. Stock repurchased and retired since beginning of stock repurchase program in 2006, shares Stock repurchased and retired since inception shares Stock repurchased and retired since inception of stock repurchase program, shares. Stock repurchased and retired since beginning of stock repurchase program in 2006, cost Stock repurchased and retired since inception, value Stock repurchased and retired since inception, value. Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block] Schedule Of Carrying Amounts And Estimated Fair Values Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule Of Fair Value Of Long-term Assets And Liabilities Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Other Income - Net Schedule of Other Nonoperating Income, by Component [Table Text Block] Lease Commitments Leases of Lessee Disclosure [Text Block] Pensions And Other Postretirement Benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Earnings Per Share Earnings Per Share [Text Block] Other Income - Net Other Income and Other Expense Disclosure [Text Block] Document And Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Debt Debt Disclosure [Text Block] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Liabilities Other Liabilities [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Purchased Services and Rent Purchased Services and Rent [Member] Purchased Services and Rent [Member] Conrail Equity Equity Method Investee [Member] Conrail Voting Affiliate Voting [Member] Voting interest in affiliate. Shared Assets Areas CRC Lease Fixed Maturities [Member] Equity method investment, ownership percentage Equity Method Investment, Ownership Percentage Pension plan status change in investment, affiliate Pension Plan Status, Change In Investment, Affiliate Pension Plan Status, Change In Investment, Affiliate Portion of pension plan change attributable to other comprehensive income (loss), affiliate Pension Plan Status Change Attributable To Other Comprehensive Income (Loss), Affiliate Pension Plan Status Change Attributable To Other Comprehensive Income (Loss), Affiliate Portion of pension plan change attributable to deferred taxes, affiliate Pension Plan Status Change Attributable To Deferred Taxes Affiliate Pension Plan Status Change Attributable To Deferred Taxes, Affiliate Difference between investment in Conrail and share of Conrail's underlying net equity Equity Method Investment, Difference Between Carrying Amount and Underlying Equity Expenses for the use of the Shared Assets Area Expenses For Use Of Shared Assets Area "Purchased services and rents" and "fuel" expenses for the use of the Shared Assets Area. Future annual minimum payments, due next five years Future Annual Minimum Payments, Due Next Five Years Future annual minimum payments due to Consolidated Rail Corporation for operation of the shared asset areas in the next five years. 2020 and subsequent years - Operating Leases General and administrative support to Conrail Accounts Receivable, Net Due to affiliate, current Due to Affiliate, Current Due to affiliate, noncurrent Due to Affiliate, Noncurrent Due to affiliate, noncurrent, maturity date Long Term Advances Due To Affiliate Maturity Date Maturity date of long-term advances due to an affiliate. Due to affiliate, average interest rate Due to affiliate, average interest rate The average interest rate associated with long-term advances from an affiliate. Statement of Comprehensive Income [Abstract] Other comprehensive income (loss), before tax: Other Comprehensive Income (Loss), before Tax [Abstract] Pension and other postretirement benefits Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax Other comprehensive income (loss) of equity investees Other Comprehensive Income Loss Of Equity Investees Amount of other comprehensive income or loss associated with equity investees for the reporting period. Other comprehensive income (loss), before tax Other Comprehensive Income (Loss), before Tax Income tax benefit (expense) related to items of other comprehensive income (loss) Other Comprehensive Income (Loss), Tax Other comprehensive income (loss), net of tax Net loss arising during the year Defined Benefit Plan Net Gain Loss During Year Net gain or loss arising during the year for defined benefit plans recognized in other comprehensive income/loss for the reporting period. Prior service effect of plan amendment Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax Amortization of net losses Amortization Of Net Losses Recognized In Other Comprehensive Income Loss Amortization of net losses associated with defined benefit plans recognized in other comprehensive income/loss for the reporting period. Amortization of prior service benefit (cost) Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax Total recognized in other comprehensive loss Other Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Net Gain Loss Before Tax Other Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Net Gain Loss Before Tax Total recognized in net periodic cost and other comprehensive loss Pension And Other Postretirement Benefit Obligations And Plan Assets Schedule of Defined Benefit Plans Disclosures [Table Text Block] Pension And Other Postretirement Benefit Cost Components Schedule of Net Benefit Costs [Table Text Block] Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Loss Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Pension And Other Postretirement Benefit Assumptions Schedule of Assumptions Used [Table Text Block] Health Care Cost Trend Assumptions Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block] Pension Plan Weighted-Average Asset Allocations, By Asset Category Pension Plan Weighted-Average Asset Allocations [Table Text Block] The weighted-average asset allocations by asset category for the reporting period associated with the pension plan. Fair Value Of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Estimated Future Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Pretax Amount Pretax Amount [Member] Pretax amount of other comprehensive income (loss) components. Tax Expense Benefit Tax Expense Benefit [Member] Tax (expense) benefit of other comprehensive income (loss) components. Net Of Tax Amount Net Of Tax Amount [Member] Net-of-tax amount of other comprehensive income (loss) components. Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Pensions and other postretirement benefits Pension And Other Postretirement Benefits Amortization Effect of amortization of pension and other postretirement benefits on other comprehensive income (loss) for the period. Reclassification adjustments for costs included in net income Reclassification Adjustments For Costs Included In Net Income Amount of reclassification adjustments related to pension and other post retirement benefits included in net income during the reporting period. Subtotal Total Pension And Other Postretirement Other Comprehensive Income Loss Amount of the total pension and other postretirement benefits effect on other comprehensive income (loss) for the period. Other comprehensive income loss of equity investees Other Comprehensive Income (Loss), Tax Net retiree other postretirement benefit obligations (Note 11) Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Long-term advances from Conrail (Note 5) Due to Affiliate Net pension benefit obligations (Note 11) Net pension obligations This element is used to disclose the amount as of the balance sheet date of noncurrent liabilities related to net pension obligations. Casualty and other claims (Note 16) Casualty And Other Claims Total amount of obligations incurred and payable related to casualty and other claims. Deferred compensation Deferred Compensation Liability, Classified, Noncurrent Other Other Accrued Liabilities, Noncurrent Total Schedule II - Valuation And Qualifying Accounts Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Available for future grants Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Shares of Common Stock issued Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Change in benefit obligations: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Benefit obligation at beginning of year Defined Benefit Plan, Benefit Obligation Actuarial losses (gains) Defined Benefit Plan, Actuarial Gain (Loss) Plan amendments Defined Benefit Plan, Plan Amendments Benefits paid Defined Benefit Plan, Benefits Paid Benefit obligation at end of year Change in plan assets: Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair value of plan assets at beginning of year Defined Benefit Plan, Fair Value of Plan Assets Actual return on plan assets Defined Benefit Plan, Actual Return on Plan Assets Employer contribution Defined Benefit Plan, Contributions by Employer Benefits paid Fair value of plan assets at end of year Funded status at end of year Defined Benefit Plan, Funded Status of Plan Noncurrent assets Defined Benefit Plan, Assets for Plan Benefits, Noncurrent Current liabilities Defined Benefit Pension Plan Liabilities, Current Noncurrent liabilities Defined Benefit Pension Plan, Liabilities, Noncurrent Net amount recognized Defined Benefit Plan, Amounts Recognized in Balance Sheet Net loss (gain) Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Actuarial Gain (Loss), before Tax Prior service cost (benefit) Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax International Equity Securities Common Stock Pension Plan Assets Common Stock This element is used to disclose the value of common stock related to total pension plan assets. Common collective trusts Pension Plan Assets Common Collective Trusts This element is used to disclose the value of common collective trusts related to total pension plan assets. Commingled funds Pension Plan Assets Commingled Funds This element is used to disclose the value of commingled funds related to total pension plan assets. Interest bearing cash Pension Plan Assets Interest Bearing Cash This element is used to disclose the value of interest bearing cash related to total pension plan assets. U.S. government and agencies securities Pension Plan Assets US Government And Agencies Securities This element is used to disclose the value of U.S. Government and agencies securities related to total pension plan assets. Preferred stock Pension Plan Assets Preferred Stock Pension Plan Assets Preferred Stock Total pension plan assets Pension Plan Assets Total This element is used to disclose the total value of pension plan assets.