Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Statement, Scenario [Axis] Statement, Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Successor Successor [Member] Predecessor Predecessor [Member] Statement [Line Items] Statement [Line Items] OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income to net cash provided by operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Deferred income taxes Deferred Income Tax Expense (Benefit) Long-term casualty and environmental liabilities, net Long term casualty and environmental liabilities, net The net change during the reporting period in the amount of noncurrent costs accrued for casualty, environmental and other loss contingencies. Contributions to defined benefit pension plan Pension Contributions Other, net Other, net The net cash inflow (outflow) from other operating activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Changes in current assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable, net Increase (Decrease) in Accounts Receivable Change in accounts receivable securitization program Change in Accounts Receivable Securitization Program Change in Accounts Receivable Securitization Program Materials and supplies Inc(Dec) in Materials and Supplies The net change during the reporting period in the aggregate value of all materials and supplies held by the reporting entity, associated with underlying transactions that are classified as operating activities. Other current assets Increase (Decrease) in Other Current Assets Accounts payable and other current liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures excluding equipment Capital Expenditures Excluding Equipment The cash outflow associated with the acquisition of long-lived, physical assets, excluding equipment, that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets. Acquisition of equipment Acquisition of equipment The cash outflow associated with the acquisition of equipment which includes locomotive, freight cars and other equipment, some or all of which may be sold and leased back by the Company through either an operating or capital lease. Other, net Payments for (Proceeds from) Other Investing Activities Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt Payments on long-term debt Repayments of Long-term Debt Cash distributions Cash Distributions/ Dividends Paid The cash outflow from the distribution of an entity's earnings in the form of dividends to common shareholders or distributions to the parent company. Other, net Proceeds from (Payments for) Other Financing Activities Net cash provided by (used for) by financing activities Net Cash Provided by (Used in) Financing Activities 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] Beginning of period Cash and Cash Equivalents, at Carrying Value End of period SUPPLEMENTAL CASH FLOW INFORMATION Supplemental Cash Flow Information [Abstract] Interest paid, net of amounts capitalized Interest Paid, Net Capital investments accrued but not yet paid Capital Expenditures Incurred but Not yet Paid Income taxes paid, net of refunds Income Taxes Paid, Net Non-cash asset financing Capital Lease Obligations Incurred Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Other Assets, Noncurrent [Abstract] Other Assets Other Asset, Investment in Variable Interest Entity [Text Block] Other Asset, Investment in Variable Interest Entity [Text Block] Consolidated Statements of Comprehensive Income [Abstract] Consolidated Statements of Comprehensive Income [Abstract] Net income Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax [Abstract] Change in amortization of accumulated actuarial losses, net of tax expense of $2 million and $0, respectively Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net (Gain) Loss Recognized in Net Periodic Benefit Cost, Net of Tax Change in fuel hedge mark-to-market, net of tax benefit of $4 million and tax expense of $25 million Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Change in accumulated other comprehensive income of equity method investees Change In Other Comprehensive Income Of Equity Method Investees Change In Other Comprehensive Income Of Equity Method Investees. Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Accounting Pronouncements Description of New Accounting Pronouncements Not yet Adopted [Text Block] Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents 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. Current portion of deferred income taxes Deferred Tax Assets, Net, Current Other current assets Other Assets, Current Total current assets Assets, Current Property and equipment, net of accumulated depreciation of $1,235 and $1,056, respectively Property, Plant and Equipment, Net Goodwill Goodwill Intangible assets, net Finite-Lived Intangible Assets, Net Other assets Other Assets, Noncurrent Total assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable and other current liabilities Accounts Payable and Accrued Liabilities, Current Long-term debt due within one year Long-term Debt and Capital Lease Obligations, Current Total current liabilities Liabilities, Current Deferred income taxes Deferred Tax Liabilities, Noncurrent Long-term debt Long-term Debt and Capital Lease Obligations Intangible liabilities, net Intangible liabilities, net The aggregate sum of gross carrying value of a major finite-lived intangible liability class, less accumulated amortization and any impairment charges. Casualty and environmental liabilities Casualty and environmental liabilities Noncurrent portion of costs accrued as of the balance sheet date for casualty, environmental and other loss contingencies. Pension and retiree health and welfare liability Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Other liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (see Notes 2, 6 and 7) Commitments and Contingencies Equity: Stockholders' Equity Attributable to Parent [Abstract] Member's equity Member's equity Total of Member's Capital (deficit) items, which includes both contributed capital and earned capital. Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total equity Stockholders' Equity Attributable to Parent Total liabilities and equity Liabilities and Equity Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income Comprehensive Income (Loss) Note [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Other Intangible Assets and Liabilities Goodwill and Intangible Assets Disclosure [Text Block] Receivables [Abstract] Accounts Receivable, Net Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Compensation and Retirement Disclosure [Abstract] Employment Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Accounting Policies and Interim Results [Abstract] Accounting Policies and Interim Results [Abstract] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Consolidated Statements of Changes in Equity [Abstract] Consolidated Statements of Changes in Equity [Abstract] Report Date [Axis] Report Date [Axis] Financial Statements Date [Domain] Financial Statements Date [Domain] Statement, Equity Components [Axis] Statement, Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Members Equity [Member] Members Equity [Member] Member's equity. Accumulated Other Comprehensive Income (Loss) [Member] Accumulated Other Comprehensive Income (Loss) [Member] Parent [Member] Parent [Member] Balance Cash Distributions To Parent Cash Distributions To Parent Company By Reporting Entity Cash distributions declared to parent company by the reporting entity. Comprehensive income, net of tax Balance Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Debt Disclosure [Abstract] Debt Debt Disclosure [Text Block] Income Statement [Abstract] Revenues Revenue, Net Operating expenses: Operating Expenses [Abstract] Compensation and benefits Labor and Related Expense Fuel Fuel Costs Purchased services Purchased services The amount of expense for contract services provided to the Company. Equipment rents Equipment rents 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. 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 operating expenses Operating Expenses Operating income Operating Income (Loss) Interest expense Interest and Debt Expense Other expense, net Other Nonoperating Income (Expense) Income before income taxes Income before income taxes Sum of operating profit (loss) and non-operating income (expense) before income taxes. Income tax expense Income Tax Expense (Benefit) Net income OCI Parenthetical [Abstract] OCI Parenthetical [Abstract] Change in amortization of accumulated actuarial losses, net of tax expense/(benefit) Change In Unrecognized Prior Service Credit And Actuarial Losses Tax Benefit (Expense) The net tax benefit (expense) resulting from the adjustment out of other comprehensive income for prior service costs and actual losses recognized as a component of net period benefit cost during the period. Change in fuel hedge mark-to-market, net of tax expense/(benefit) Fuel Interest Hedge Mark To Market Tax Benefit (Expense) The net tax benefit (expense) resulting from the change in accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges, net of tax effect. Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Entities [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date 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 Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Public Float Entity Public Float