Amendment Flag Current Fiscal Year End Date Document Fiscal Period Focus Document Fiscal Year Focus Document Period End Date Document Type Entity Central Index Key Entity Common Stock, Shares Outstanding Entity Filer Category Entity Registrant Name This element is used to disclose the term, in days, of the Accounts Receivable Securitization Facility. Account Receivable Securitization Facility Term Days Receivables securitization facility term, days The balance as of the reporting period of the amount owed by the reporting entity to counterparties in securitized loan transactions. Accounts Receivable Securitization Balance Securitization borrowings Accounts receivable securitization balance Accumulated other comprehensive gain (loss) reclassifications adjustments Accumulated Other Comprehensive Income (Loss) Reclassification Adjustments Amounts reclassified into net income Accumulated other comprehensive loss of equity investees component of accumulated other comprehensive income Accumulated Other Comprehensive Loss Equity Investees [Member] Accumulated other comprehensive loss net gain (loss) Accumulated Other Comprehensive Loss Net Gain (Loss) Net gain Equity interest in affiliate Affiliate Equity [Member] Conrail Equity [Member] Voting interest in affiliate Affiliate Voting [Member] Conrail Voting [Member] Allocated Share Based Compensation Benefit Stock-based compensation benefit This element is used to disclose the amount of receivables associated with the contested portion of arbitration. Arbitration Decision Expense Arbitration decision expense This element is used to disclose the authority the Company has from the Board of Directors to issue additional debt or equity securities through public or private sale. Authority To Issue Debt Equity Securities Authority to issue debt/equity securities Cash Premium Associated with Debt Exchange Cash Premium Debt Exchange Cash premium, debt exchange This element is used to disclose the contested portion of arbitration with one of the company's insurance carriers. Contested Portion Of Arbitration Contested portion of arbitration Document and Entity Information[Abstract] Document And Entity Information [Abstract] This element is used to disclose the average interest rate associated with long-term advances from an affiliate. Due to affiliate, average interest rate Employee Service Share Based Compensation Tax Expense From Compensation Benefit Tax expenses associated with stock-based compensation costs This element is used to disclose the number of known locations and projects of environmental loss contingencies. Environmental Cleanup Locations Known cleanup and remediation locations and projects Environmental Locations Representative Sample Liability Period Environmental Locations Representative Sample Liability Period Environmental locations representative sample liability payout period, in years This element is used to disclose the liability associated with the representative sample of environmental locations and projects. Environmental Locations Representative Sample Liability Liability associated with those sites This element is used to disclose a representative sample of the total number of environmental locations and projects. Environmental Locations Representative Sample Number of sites - representative sample This element is used to disclose the 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). Environmental Responsible Party In Conjunction With Other Parties Responsible locations with another party This element is used to disclose the "purchased services and rents" and "fuel" expenses for the use of the Shared Assets Area. Expenses For Use Of Shared Assets Area Expenses for the use of the Shared Assets Area The gains (losses) included in the results of operations resulting form the sale of property or investments. Gain Loss On Properties And Investments t Gains and losses on properties and investments This element is used to disclose the fair value at pay out of incentive awards paid out during the reporting period. Incentive Award Payout Fair Value Fair value at payout Sum of operating profit (loss) and non-operating income (expense) before income taxes. Income before income taxes Income before income taxes This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment losses recognized. Income Loss Equity In Affiliate Equity method investments Maturity date of long-term advances due to an affiliate Long Term Advances Due To Affiliate Maturity Date Due to affiliate, noncurrent, maturity date This element is used to disclose the number of years holders of LTIP options who remain actively employed, are eligible for dividend equivalent payments on a particular stock option grant. LTIP Dividend Equivalent Payment Years LTIP dividend equivalent payment, in years Norfolk Southern Corporation Long-Term Incentive Plan Ltip [Member] LTIP [Member] Materials and other operating expenses not separately disclosed. This element is used when other, more specific, elements are not appropriate. Materials and other Materials and other 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. Materials and supplies This element is used to identify new debt issued associated with a debt exchange New Debt Debt Exchange New debt, debt exchange New Due Date Debt Exchange New due date, debt exchange Element indicates the rate associated with new debt issued as a part of a debt exchange New Rate Debt Exchange New rate, debt exchange New Stock Repurchase Authorization New stock repurchase authorization This element is used to disclose the number of options having exercise prices exceeding the average market price of Common Stock. Options With Exercise Prices Above Average Market Price Options having exercise prices exceeding average market price This element lists principal retired through debt exchange Original Debt Original debt Element represents due date of debt retired through debt exchange Original Due Date Year Original due date, year Represents percentage rate on debt retired through debt exchange Original Rate Original rate This element is used to disclose the amount of other receivables associated with the arbitration claim for which recovery is no longer probable. Other Arbitration Expense Other arbitration expense This element is used to disclose other comprehensive income or loss associated with equity investees for the reporting period. Other comprehensive loss of equity investess Other comprehensive loss of equity investess Other Comprehensive Income Loss Of Equity Investees Other comprehensive income (loss) of equity investees Pensions and other postretirement liabilities component of accumulated other comprehensive loss Pensions And Other Postretirement Liabilities [Member] Pensions And Other Postretirement Liabilities [Member] Percentage of PSUs grants earned and paid in cash. Percentage Of Performance Share Units Grants Earned And Paid In Cash Percentage of PSUs grants earned and paid in cash Percentage of PSUs grants earned and paid in common shares. Percentage Of Performance Share Units Grants Earned And Paid In Common Shares Percentage of PSUs grants earned and paid in common shares This element is used to disclose the number of PSUs paid out in Common Stock, net of any forfeits and unearned awards. Performance Share Units Paid Performance share units paid Performance share units earned Performance Share Units (PSUs) [Member] Performance Share Units Psus [Member] PSU [Member] Previously Issued Notes Member Previously Issued Notes Member Previously Issued Notes [Member] Proceeds From Stock Options Exercised, Including Tax Benefit Proceeds From Stock Options Exercised Including Tax Benefit Common stock issued, net This elements is used to disclose the cycle, in years, when corporate performance achieves predetermined goals. PSU Cycle Performance Share Units Cycle, in years 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. Purchased services and rents This element is used to disclose the period of time over which an employee's restricted stock unit award is earned. Restricted Stock Unit Restriction Period Restriction period, in years This element is used to disclose the number of restricted stock units paid out in stock during the period related to Restricted Stock Unit awards, net of any forfeits. Restricted Stock Units Paid In Stock Restricted stock units earned and paid in stock Restricted stock units vested Restricted Stock Units Tax Benefit Expense Restricted Stock Units Tax Benefit Expense Restricted Stock Units tax (expense) benefit This element is used to disclose the amount above which the company is self-insured per occurrence for bodily injury and property damage to third parties. Self Insured For Bodily Injury And Property Damage To Third Parties Above Self-insured injury/damage to third parties - and above, per occurrence This element is used to disclose the amount up to which the company is self-insured per occurrence for bodily injury and property damage to third parties. Self Insured For Bodily Injury And Property Damage To Third Parties Up To Self-insured injury/damage to third party - up to This element is used to disclose the amount above which the company is self-insured, per occurrence, for property owned or in the care, custody or control of the company. Self-Insured For Property Owned Above Self-insured NS owned property - and above, per occurrence This element is used to disclose the 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 For Property Owned Up To Self-insured NS owned property - up to Senior Note Five Point Five Nine Percent Due Two Thousand Twenty Five [Member] Senior Note Five Point Five Nine Percent Due Two Thousand Twenty Five Member Senior Note 5.59% Due 2025 [Member] Senior Note Five Point Six Four Percent Due Two Thousand Twenty Nine [Member] Senior Note Five Point Six Four Percent Due Two Thousand Twenty Nine Member Senior Note 5.64% Due 2029 [Member] Senior Note Seven Point Eight Percent Due Two Thousand Twenty Seven Member Senior Note Seven Point Eight Percent Due Two Thousand Twenty Seven Member Senior Note 7.80% Due 2027 [Member] Senior Note Seven Point Two Five Percent Due Two Thousand Thirty One [Member] Senior Note Seven Point Two Five Percent Due Two Thousand Thirty One Member Senior Note 7.25% Due 2031 [Member] Senior Note Seven Point Zero Five Percent Due Two Thousand Thirty Seven Member Senior Note Seven Point Zero Five Percent Due Two Thousand Thirty Seven Member Senior Note 7.05% Due 2037 [Member] Senior Note Three Percent Due Two Thousand Twenty Two [Member] Senior Note Three Percent Due Two Thousand Twenty Two Member Senior Note 3.00% Due 2022 [Member] Senior note Three Point 95 Percent Due 2042 [Member] Senior Note Three Point Nine Five Percent Due Two Thousand Forty Two Member Senior Note 3.95% Due 2042 [Member] Senior Note Two Point Nine Percent Due Two Thousand Twenty Three [Member] Senior Note Two Point Nine Percent Due Two Thousand Twenty Three Member Senior Note 2.90% Due 2023 [Member] Documents the compensation other than options 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 Shares issued net of withholding taxes 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. Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate When Dividend Equivalents Are Not 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 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 paid 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 Grant Date Fair Value Share-based compensation arrangement by share-based payment award, options, grants in period grant date fair value Option per share grant-date fair value The grant-date fair value of incentive awards paid out during the reporting period. Share Based Compensation Arrangement By Share Based Payment Award Options Paid Out In Period Grant Date Fair Value Grant-date fair value for PSUs paid out Stock Repurchase Program [Abstract] Stock Repurchase Program [Abstract] Stock repurchased and retired since inception of stock repurchase program, shares. Stock repurchased and retired since inception shares Stock repurchased and retired since beginning of stock repurchase program in 2006, shares Stock repurchased and retired since inception, value. Stock repurchased and retired since inception, value Stock repurchased and retired since beginning of stock repurchase program in 2006, cost Reductions in the entity's income taxes that arise when compensation cost (from incentive awards) recognized on the entity's tax return exceeds compensation cost from incentive awards recognized on the income statement. Tax Benefit Expense From Incentive Awards Performance Share Units tax benefit (expense) Norfolk Southern Corporation Thoroughbred Stock Option Plan Tsop [Member] TSOP [Member] Accounts payable Accounts payable Total accounts payable Accounts receivable - net Accounts receivable, net Accounts Receivable, Net, Current, Total Accrual for Environmental Loss Contingencies, Undiscounted, Due within One Year Current environmental liability Accrual for Environmental Loss Contingencies, Ending Balance Accrual for Environmental Loss Contingencies, Beginning Balance Accrual for Environmental Loss Contingencies Environmental liability Accrual for Environmental Loss Contingencies, Total Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total Properties, accumulated depreciation Accumulated Depreciation Accumulated Other Comprehensive Income (Loss) Defined Benefit Pension And Other Postretirement Plans, Net Of Tax Pensions and other postretirement liabilities - ending balance Pensions and other postretirement liabilities - beginning balance Accumulated other comprehensive loss - ending balance Accumulated other comprehensive loss - beginning balance Accumulated other comprehensive loss Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated other comprehensive loss Accumulated other comprehensive loss - ending balance Accumulated other comprehensive loss - beginning balance Additional Paid in Capital, Ending Balance Additional Paid in Capital, Beginning Balance Additional Paid In Capital Additional paid-in capital Additional Paid in Capital, Total Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities Abstract Reconciliation of net income to net cash provided by operating activities: Allocated Share-based Compensation Expense Stock-based compensation expense Allocated Share-based Compensation Expense, Total Stock-based compensation expense Assets Abstract Assets Total current assets Total current assets Assets Fair Value Disclosure Assets or liabilities measured at fair value Assets Total assets Available-for-sale Securities, Fair Value Disclosure Fair value available-for-sale securities valued under Level 2 Award Type [Axis] Cash and Cash Equivalents, at Carrying Value [Abstract] Cash and cash equivalents At end of period At beginning of year Cash and cash equivalents at carrying value Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value, Total Net increase (decrease) in cash and cash equivalents Net increase (decrease) in cash and cash equivalents Net increase (decrease) in cash and cash equivalents Class Of Stock [Domain] Class of Stock [Domain] Commitments And Contingencies [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments And Contingencies Common Stock Dividends Per Share Cash Paid Dividends 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, Ending Balance Common Stock, Shares, Outstanding, Beginning Balance Common Stock, Shares, Outstanding, net of treasury shares Common stock, shares outstanding, net of treasury shares Common stock $1.00 per share par value, 1,350,000,000 shares authorized; outstanding 315,088,379 and 314,034,174 shares, respectively, net of treasury shares Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income Total comprehensive income Cost Of Services Depreciation Depreciation Debt [Abstract] Debt Disclosure [Text Block] Debt Debt Instrument, Fair Value Long-term debt fair value Long-term debt, including current maturities, fair value Long-term debt, including current maturities Debt instrument, interest rate, stated percentage Debt Instrument [Line Items] Debt Instrument, Maturity Date, Description Debt instrument, maturity date, year Schedule of Long-term Debt Instruments [Table] Deferred Income Tax Expense (Benefit), Total Deferred income taxes Total deferred income taxes Deferred Income Tax Expense (Benefit), Total Deferred Tax Assets, Net, Current, Ending Balance Deferred Tax Assets, Net, Current, Beginning Balance Deferred Tax Assets Net Current Deferred income taxes Deferred Tax Assets, Net, Current, Total Net current deferred tax asset Deferred Tax Liabilities Noncurrent Deferred income taxes Net long-term deferred tax liability Net long-term deferred tax liability Net long-term deferred tax liability Net long-term deferred tax liability Defined Benefit Plan Amortization Of Net Gains Losses Amortization of net losses Estimated net loss amortized from AOCI into net periodic cost Amortization of prior service cost Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Expected Return On Plan Assets Expected return on plan assets Defined Benefit Plan Interest Cost Interest cost Defined Benefit Plan Net Periodic Benefit Cost Net cost Net cost Defined Benefit Plan Service Cost Service cost Defined Benefit Plans Disclosures, Defined Benefit Plans [Axis] Defined Benefit Plans [Domain] Defined Benefit Plans [Domain] Pensions And Other Postretirement Benefits [Abstract] Depreciation Depreciation, Total Stock Based Compensation Abstract Stock-Based Compensation StockBasedCompensationAbstract Stock-Based Compensation [Abstract] Due to Affiliate, Current Due to affiliate, current Due to Affiliate, Noncurrent Due to affiliate, noncurrent Earnings Per Share [Abstract] Per share amounts: Earnings Per Share Basic [Member] Earnings Per Share, Basic [Member] Basic Basic earnings per share Basic Earnings Per Share Diluted [Member] Earnings Per Share, Diluted [Member] Diluted Diluted earnings per share Diluted Earnings Per Share [Text Block] Earnings Per Share Investment in Conrail [Axis] Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Tax benefits associated with compensation costs Tax benefits associated with stock-based compensation costs Tax benefits associated with stock-based compensation costs Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options Related excess tax benefits realized Excess tax benefits recognized for share-based awards Employee Stock Ownership Plan (ESOP), Dividends Paid to ESOP Dividend equivalent payments Dividend equivalent payments Stockholders' Equity [Abstract] Equity Component [Domain] Equity method investment, ownership percentage Equity Method Investments [Member] Accumulated Other Comprehensive Loss of Equity Investees [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 [Table] Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule Of Carrying Amounts And Estimated Fair Values Schedule Of Carrying Amounts And Estimated Fair Values Fair Value, Hierarchy [Axis] Fair Value [Abstract] Fair Value Inputs Level1 [Member] Level 1 [Member] Fair Value Inputs Level2 [Member] Level 2 [Member] Fair Value Measurement Inputs Disclosure [Text Block] Fair Value Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Option Eligible Item Or Group [Domain] Fair Value, Option, Eligible Item or Group [Domain] Fair Value, Option, Qualitative Disclosures Related to Election, by Eligible Item or Group [Axis] Fuel Income (Loss) from Equity Method Investments Equity in the earnings of Conrail Income (Loss) from Equity Method Investments, Total Equity in the earnings of Conrail Inc. (Note 5) Consolidated Statements Of Income [Abstract] Income Taxes [Abstract] Income Tax Disclosure [Text Block] Income Taxes Provision for income taxes Provision for income taxes Provision for income taxes Provision for income taxes Income taxes (net of refunds) Income Taxes Paid, Net, Total Accounts receivable Accounts receivable Accounts receivable increase (decrease) in Materials and supplies Materials and supplies Materials and supplies Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities affecting operations: Increase (Decrease) in Other Current Assets Other current assets Current liabilities other than debt Current liabilities other than debt Increase (Decrease) in Other Operating Liabilities, Total Interest expense on debt Interest expense on debt Interest expense on debt Interest (net of amounts capitalized) Interest Paid, Net, Total Investment Holdings [Text Block] Investment In Conrail Short-term investments Investment In Conrail [Abstract] Compensation and benefits Labor and Related Expense, Total Liabilities and stockholders' equity [Abstract] Liabilities and stockholders' equity Liabilities and Stockholders' Equity Total liabilities and stockholders' equity Total current liabilities Total current liabilities Liabilities Total liabilities Current maturities of long-term debt Current maturities of long-term debt Current maturities of long-term debt Long Term Debt And Capital Lease Obligations Long-term debt Long-term Debt and Capital Lease Obligations, Total Long-term Debt Long-term debt carrying value Long-term Debt, Total Long-term debt, including current maturities, carrying value Long Term Investments Investments Total long-term investments Total long-term investments Long-term Purchase Commitment, Amount Purchase commitments, long-term service contracts Long-term Debt, Type [Axis] Longterm Debt Type [Domain] Long-term Debt, Type [Domain] Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities Net Cash Used in Investing Activities Net cash used in investing activities Cash flows from operating activities Net cash provided by operating activities Net cash provided by operating activities Net Income (Loss) Available to Common Stockholders, Basic Income available to common stockholders, basic Income available to common stockholders Net Income (Loss) Available to Common Stockholders, Diluted Income available to common stockholders, diluted Net Income (Loss) Available to Common Stockholders, Diluted, Total New Accounting Pronouncements [Abstract] New Accounting Pronouncements [Text Block] Operating Expenses [Abstract] Railway operating expenses: Operating Expenses Total railway operating expenses Income from railway operations Income from railway operations Other current assets Other current assets Other assets Other assets Other assets Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax Pension and other postretirement benefits Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Total Other comprehensive income, before tax: Other Comprehensive Income (Loss), before Tax Other comprehensive income, before tax Other comprehensive income, before tax Other comprehensive income, before tax Other Comprehensive Income (Loss), Net of Tax Other comprehensive income, net of tax Other comprehensive income, net of tax Other comprehensive income (loss) Other comprehensive income Other comprehensive income, net of tax Pension and other postretirement benefit Pension and other postretirement benefits Other Comprehensive Income (Loss), Tax Income tax expense related to items of other comprehensive income Other Comprehensive Income (Loss), Tax, Total Income tax expense related to items of other comprehensive income Other Liabilities Current Other current liabilities Total other current liabilities Other Liabilities, Noncurrent, Total Other Liabilities Noncurrent Other liabilities Total Other Nonoperating Income Expense Other income, net Total other income - net Other Nonoperating Income (Expense), Total Other Operating Activities, Cash Flow Statement Other, net Other Postretirement Benefit Plans Defined Benefit [Member] Other Postretirement Benefit Plans, Defined Benefit [Member] Payments for (Proceeds from) Other Investing Activities Investment sales and other transactions Investment sales and other transactions Investment sales and other transactions Purchase and retirement of common stock Purchase and retirement of common stock Payments of Dividends, Common Stock Dividends Investments, including short-term Payments to Acquire Investments, Total Investments, including short-term Property additions Payments to Acquire Property, Plant, and Equipment, Total Property additions Pension And Other Postretirement Benefits Disclosure [Text Block] Pensions And Other Postretirement Benefits Pension Plans Defined Benefit [Member] Pension Plans, Defined Benefit [Member] Proceeds from Debt, Net of Issuance Costs Proceeds from borrowings, net Proceeds from borrowings - net Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt, Total Proceeds from Sale of Available-for-sale Securities Sales of available-for-sale securities Proceeds from Sale of Available-for-sale Securities, Total Property sales and other transactions Proceeds from Sale of Property, Plant, and Equipment, Total Proceeds from Short-term Debt Proceeds from Short-term Debt, Total Proceeds from issuance of short-term debt Proceeds from Stock Options Exercised Proceeds from stock options exercised Net income Net income Net income Property, Plant and Equipment, Net, Ending Balance Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net Properties less accumulated depreciation of $10,042 and $9,922, respectively Property, Plant and Equipment, Net, Total Net Book Value Debt Repayments Debt repayments Debt repayments Repayments of Short-term Debt Repayments of short-term debt Repayments of Short-term Debt, Total Restricted Stock Units R S U [Member] Restricted Stock Units (RSUs) [Member] Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit), Beginning Balance Retained income Retained income Retained income Railway operating revenues Railway operating revenues Revenues, Total Schedule Of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Accumulated Other Comprehensive Loss Schedule of Defined Benefit Plans Disclosures [Table] Schedule Of Earnings Per Share Basic And Diluted [Table Text Block] Schedule Of Earnings Per Share Calculation Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule Of Fair Value Of Long-term Assets And Liabilities Schedule of Investments [Line Items] Schedule of Investments [Table] Schedule of Net Benefit Costs [Table Text Block] Pension And Other Postretirement Benefit Cost Components Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule Of Assumptions Used For LTIP And TSOP Grants ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Award vesting period, grant anniversary Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Grant-date fair value of units granted 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 Granted Grants other than stock options Share Based Compensation Arrangement By Share Based Payment Award Expiration Date Stock option term, in years Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Maximum Expected volatility rate, maximum Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Minimum Expected volatility rate, minimum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Average risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate Average expected volatility rate Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Grant price of options granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period Granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total Stock options granted Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Share-based Compensation Arrangements by Share-based Payment Award, Award Type and Plan Name [Domain] Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 Average expected option term, in years Short-term debt Short-term Borrowings, Total Proceeds from issuance of short-term debt Short-term Debt, Weighted Average Interest Rate Average variable interest rate Short-term investments Total short-term investments Total short-term investments Class of Stock [Axis] Statement, Equity Components [Axis] Statement [Line Items] Consolidated Statements Of Cash Flows [Abstract] Consolidated Balance Sheets [Abstract] Consolidated Statements Of Comprehensive Income [Abstract] Statement [Table] Stock Issued During Period, Shares, Stock Options Exercised Stock options exercised Options exercised Stock options exercised Stock repurchased and retired during period, shares Share repurchases Share repurchases - cost Stock repurchased and retired during period, cost Share repurchases Stockholders' equity: Balance Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total stockholders' equity Stockholders' Equity Note Disclosure [Text Block] Stockholders' Equity Summary of Investments, Other than Investments in Related Parties, Carrying Amount Long-term investments, carrying value Summary of Investments, Other than Investments in Related Parties, Fair Value Long-term investments, fair value Long-term investments Supplemental Cash Flow Information [Abstract] Supplemental disclosure of cash flow information Income and other taxes Taxes Payable, Current, Total Treasury Stock, Number of Shares Held Shares held by consolidated subsidiaries Treasury Stock [Text Block] Stock Repurchase Program Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Treasury Stock, Value Value of shares held by consolidated subsidiaries Weighted Average Number Diluted Shares Outstanding Adjustment Dilutive effect of outstanding options and share-settled awards Weighted Average Number Diluted Shares Outstanding Adjustment, Total Weighted Average Number of Shares Outstanding, Diluted Adjusted weighted-average shares outstanding Weighted Average Number of Shares Outstanding, Diluted, Total Weighted Average Number of Shares Outstanding, Basic Weighted-average shares outstanding Weighted Average Number of Shares Outstanding, Basic, Total