2.2.0.7 true Merger (Details) (USD $) 0602 - Disclosure - Merger (Details) true false false false 1 USD true false false false bni_ProFormaMember us-gaap_StatementScenarioAxis xbrldi http://xbrl.org/2006/xbrldi bni_ProFormaMember us-gaap_StatementScenarioAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 2 USD true false false false bni_ProFormaMember us-gaap_StatementScenarioAxis xbrldi http://xbrl.org/2006/xbrldi bni_ProFormaMember us-gaap_StatementScenarioAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 3 USD true false false false us-gaap_PredecessorMember us-gaap_StatementScenarioAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_PredecessorMember us-gaap_StatementScenarioAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 5 Purchase price allocation 3 us-gaap_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false xbrli:stringItemType string No definition available. false 6 Cash paid as merger consideration 4 us-gaap_BusinessAcquisitionCostOfAcquiredEntityCashPaid us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 true true false false 15874000000 15874000000 true false false xbrli:monetaryItemType monetary Amount of cash paid to acquire the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph f(1) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph d false 7 Value of Berkshire common stock issued as merger consideration 4 bni_ValueOfAcquiringCompanyCommonStockIssuedAsMergerConsideration bni false debit instant Value of acquiring company common stock issued as merger consideration. false false false false false false false false false false false totallabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 10577000000 10577000000 true false false xbrli:monetaryItemType monetary Value of acquiring company common stock issued as merger consideration. No authoritative reference available. true 8 Total merger consideration to acquire the remaining shares of Predecessor 4 bni_TotalMergerConsiderationToAcquireRemainingSharesOfPredecessor bni false debit instant Total merger consideration to acquire the remaining shares of predecessor. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 26451000000 26451000000 true false false xbrli:monetaryItemType monetary Total merger consideration to acquire the remaining shares of predecessor. No authoritative reference available. false 9 Value of Predecessor already owned by Berkshire valued at merger price of $100.00 per share 4 bni_ValueOfPredecessorAlreadyOwnedByAcquiringCompanyValuedAtMergerPriceOfHundredPerShare bni false debit instant Value of Predecessor already owned by Berkshire valued at merger price of $100.00 per share. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 7678000000 7678000000 true false false xbrli:monetaryItemType monetary Value of Predecessor already owned by Berkshire valued at merger price of $100.00 per share. No authoritative reference available. false 10 Value of Berkshire equity awards to replace pre-existing Predecessor equity awards 4 bni_ValueOfAcquiringCompanyEquityAwardsToReplacePreExistingPredecessorEquityAwards bni false debit instant Value of Berkshire equity awards to replace pre-existing Predecessor equity awards. false false false false false false false false false false false totallabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 366000000 366000000 true false false xbrli:monetaryItemType monetary Value of Berkshire equity awards to replace pre-existing Predecessor equity awards. No authoritative reference available. true 11 Total purchase price to be allocated 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 34495000000 34495000000 true false false xbrli:monetaryItemType monetary The total purchase price of the acquired entity. This includes cash paid to equity interest holders of the acquired entity, fair value of debt and equity securities issued to equity holders of the acquired entity, and transaction costs paid to third parties to consummate the acquisition. 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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e false 14 Accounts receivable, net 4 us-gaap_BusinessCombinationAcquiredReceivablesFairValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 808000000 808000000 true false false xbrli:monetaryItemType monetary For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of the receivables acquired, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 03-3 -Paragraph 3 -Subparagraph a-g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 6 -Subparagraph b(ii) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph h(1) false 15 Material and supplies 4 bni_BusinessCombinationPurchasePriceAllocationCurrentAssetsMaterialsAndSupplies bni false debit instant The amount of acquisition cost of a business combination allocated to unapplied materials and supplies to be used in the... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 630000000 630000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to unapplied materials and supplies to be used in the performance or support of carrier operations acquired in a business combination. No authoritative reference available. false 16 Current portion of deferred income taxes 4 bni_BusinessAcquisitionPurchasePriceAllocationCurrentPortionOfDeferredIncomeTaxes bni false debit instant The amount of acquisition cost of a business combination allocated to the current portion of deferred income taxes. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 210000000 210000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to the current portion of deferred income taxes. No authoritative reference available. false 17 Other current assets 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsPrepaidExpenseAndOtherAssets us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 144000000 144000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to prepaid expenses and other current assets. Does not include amounts allocated to cash and cash equivalents, marketable securities, receivables, inventory, and assets not to be used. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e false 18 Property and equipment, net 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 43987000000 43987000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to property, plant and equipment to be used in ongoing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 -Subparagraph d false 19 Goodwill 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 14803000000 14803000000 true false false xbrli:monetaryItemType monetary Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 52 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 53 -Subparagraph d false 20 Intangible assets, net 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 2025000000 2025000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to an identifiable intangible asset that will be amortized. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 52 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e false 21 Other assets 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentAssets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 2095000000 2095000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to noncurrent assets of the acquired entity, except for property plant and equipment, intangible assets, and goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 98-1 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 -Subparagraph f true 22 Total assets 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationAssetsAcquired us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 65673000000 65673000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to assets acquired. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 -Subparagraph g true 23 Liabilities and net assets acquired 3 bni_LiabilitiesAndNetAssetsAcquiredAbstract bni false na duration Liabilities and net assets acquired. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false xbrli:stringItemType string Liabilities and net assets acquired. false 24 Accounts payable and other current liabilities 4 bni_BusinessAcquisitionPurchasePriceAllocationAccountsPayableAndOtherCurrentLiabilities bni false credit instant The amount of acquisition cost of a business combination allocated to accounts payable and other current liabilities. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 2261000000 2261000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to accounts payable and other current liabilities. No authoritative reference available. false 25 Long-term debt due within one year 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesLongTermDebt us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 649000000 649000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to the current portion of long-term debt of the acquired entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e false 26 Long-term debt 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationNoncurrentLiabilitiesLongTermDebt us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 10493000000 10493000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to the noncurrent portion of the long-term debt assumed from the acquired entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 -Subparagraph g Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 98-1 false 27 Deferred income taxes 4 bni_BusinessAcquisitionPurchasePriceAllocationNoncurrentLiabilitiesDeferredIncomeTaxes bni false credit instant The amount of acquisition cost of a business combination allocated to the noncurrent portion of the deferred income tax... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 13413000000 13413000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to the noncurrent portion of the deferred income tax liability. No authoritative reference available. false 28 Intangible liabilities, net 4 bni_BusinessAcquisitionPurchasePriceAllocationNoncurrentLiabilitiesAmortizableIntangibleLiabilities bni false credit instant The amount of acquisition cost of a business combination allocated to an identifiable intangible liabilities that will be... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 2056000000 2056000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to an identifiable intangible liabilities that will be amortized. No authoritative reference available. false 29 Casualty and environmental liabilities 4 bni_BusinessAcquisitionPurchasePriceAllocationNoncurrentLiabilitiesCasualtyAndEnvironmentalLiabilities bni false credit instant The amount of acquisition cost of a business combination allocated to Casualty and Environmental Liabilities. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 928000000 928000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to Casualty and Environmental Liabilities. No authoritative reference available. false 30 Pension and retiree health and welfare liability 4 bni_BusinessAcquisitionPurchasePriceAllocationPensionAndRetireeHealthAndWelfareLiability bni false credit instant The amount of acquisition cost of a business combination allocated to the noncurrent liability for underfunded plans... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 865000000 865000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. No authoritative reference available. false 31 Other liabilities 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentLiabilities us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 513000000 513000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to other noncurrent liabilities of the acquired entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph e false 32 Net assets acquired 4 us-gaap_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 34495000000 34495000000 true false false xbrli:monetaryItemType monetary The total purchase price of the acquired entity. This includes cash paid to equity interest holders of the acquired entity, fair value of debt and equity securities issued to equity holders of the acquired entity, and transaction costs paid to third parties to consummate the acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph d Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 35 false 33 Total liabilities and net assets acquired 4 bni_BusinessAcquisitionPurchasePriceAllocationTotalLiabilitiesAndNetAssetsAssumed bni false na instant The amount of acquisition cost of a business combination allocated to liabilities assumed and net assets acquired. false false false false false false false false false false false totallabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 65673000000 65673000000 true false false xbrli:monetaryItemType monetary The amount of acquisition cost of a business combination allocated to liabilities assumed and net assets acquired. No authoritative reference available. true 34 Pro forma financial data 3 us-gaap_BusinessAcquisitionProFormaInformationAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false xbrli:stringItemType string No definition available. false 35 Revenues 4 us-gaap_BusinessAcquisitionProFormaRevenue us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 7991000000 7991000000 true false false 2 false true false false 6878000000 6878000000 true false false 3 false false false false 0 0 true false false xbrli:monetaryItemType monetary The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph r(2, 3) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 54 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 55 false 36 Net income 4 us-gaap_BusinessAcquisitionProFormaNetIncomeLoss us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1199000000 1199000000 true false false 2 false true false false 809000000 809000000 true false false 3 false false false false 0 0 true false false xbrli:monetaryItemType monetary The pro forma net income (loss) for the period as if the business combination or combinations had been completed at the beginning of a period Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph r(2, 3) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 54 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 55 false 37 Merger (Textuals) [Abstract] 3 bni_MergerTextualsAbstract bni false na duration Merger. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false xbrli:stringItemType string Merger. false 38 Common stock shares owned by acquiring company prior to the Merger 4 bni_CommonStockSharesOfPredecessorOwnedByAcquiringCompanyPriorToMerger bni false na instant Common stock shares of Predecessor owned by acquiring company prior to the Merger. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 76777029 76777029 true false false xbrli:integerItemType integer Common stock shares of Predecessor owned by acquiring company prior to the Merger. No authoritative reference available. false 39 Percentage of the acquired company's total common stock shares issued and outstanding owned by acquiring company prior to the Merger 4 bni_PercentageOfTotalPredecessorIssuedAndOutstandingSharesOfCommonStockOwnedByAcquiringCompanyPriorToMerger bni false na instant Percentage of total Predecessor issued and outstanding shares of common stock owned by acquiring company prior to the Merger. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 0.225 0.225 true false false us-types:percentItemType pure Percentage of total Predecessor issued and outstanding shares of common stock owned by acquiring company prior to the Merger. No authoritative reference available. false 40 Common stock, par value 4 us-gaap_CommonStockParOrStatedValuePerShare us-gaap true na instant No definition available. false false false false false false false false false false false verboselabel true 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 true true false false 0.01 0.01 true false false us-types:perShareItemType decimal Face amount or stated value of common stock per share; generally not indicative of the fair market value per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 false 41 Right to receive amount if consideration paid in cash 4 bni_RightToReceiveAmountIfConsiderationPaidInCash bni false na instant Amount of cash, without interest, each share of common stock converted into the right to receive if cash was paid as... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 100 100 true false false xbrli:monetaryItemType monetary Amount of cash, without interest, each share of common stock converted into the right to receive if cash was paid as consideration. No authoritative reference available. false 42 Right to receive calculation numerator if consideration issued in stock 4 bni_RightToReceiveCalculationNumeratorIfConsiderationIssuedInStock bni false na instant Numerator amount of the exchange ratio to calculate the amount of acquirer common stock included as the right to receive per... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 100 100 true false false xbrli:monetaryItemType monetary Numerator amount of the exchange ratio to calculate the amount of acquirer common stock included as the right to receive per share of common stock if the consideration was issued in acquirer stock. No authoritative reference available. false 43 Percentage of total merger consideration paid in the form of cash 4 bni_PercentageOfTotalMergerConsiderationPaidInFormOfCash bni false na instant Percentage of total merger consideration paid in the form of cash. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 0.6 0.6 true false false us-types:percentItemType pure Percentage of total merger consideration paid in the form of cash. No authoritative reference available. false 44 Percentage of total merger consideration paid in the form of common stock 4 bni_PercentageOfTotalMergerConsiderationPaidInFormOfAcquirerCommonStock bni false na instant Percentage of total merger consideration paid in the form of acquirer common stock. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 0.4 0.4 true false false us-types:percentItemType pure Percentage of total merger consideration paid in the form of acquirer common stock. No authoritative reference available. false 45 Costs related to the merger 4 us-gaap_BusinessCombinationAcquisitionRelatedCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 62000000 62000000 true false false xbrli:monetaryItemType monetary This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 59 false 46 Accounts receivable 4 us-gaap_BusinessCombinationAcquiredReceivablesFairValue us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 808000000 808000000 true false false xbrli:monetaryItemType monetary For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of the receivables acquired, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 03-3 -Paragraph 3 -Subparagraph a-g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 6 -Subparagraph b(ii) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph h(1) false 47 Gross amount due under contracts included in the fair value of accounts receivable acquired 4 us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 862000000 862000000 true false false xbrli:monetaryItemType monetary For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual amounts receivable, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 03-3 -Paragraph 3 -Subparagraph a-g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 6 -Subparagraph b(ii) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph h(2) false 48 Estimated uncollectible amount included in the fair value of accounts receivable acquired 4 us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 54000000 54000000 true false false xbrli:monetaryItemType monetary For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the best estimate at the acquisition date of the contractual cash flows not expected to be collected, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 03-3 -Paragraph 3 -Subparagraph a-g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 6 -Subparagraph b(ii) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph h(3) false 49 Intangible assets 4 us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 2025000000 2025000000 true false false xbrli:monetaryItemType monetary The amount of identifiable intangible assets recognized as of the acquisition date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 12, 13, 14, 20, A107 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph i false 50 Intangible liabilities 4 bni_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleLiabilities bni false debit instant The amount of identifiable intangible liabilities recognized as of the acquisition date. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 2056000000 2056000000 true false false xbrli:monetaryItemType monetary The amount of identifiable intangible liabilities recognized as of the acquisition date. No authoritative reference available. false 51 Weighted average amortization life of intangible assets acquired 4 us-gaap_AcquiredFiniteLivedIntangibleAssetWeightedAverageUsefulLife us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 10 10 true false false xbrli:decimalItemType decimal The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 44 -Subparagraph a(3) false 52 Weighted average amortization life of intangible liabilities 4 bni_AcquiredFiniteLivedIntangibleLiabilitiesWeightedAverageUsefulLife bni false na duration The calculated weighted-average amortization period of a major class of finite-lived intangible liabilities acquired during... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false true false false 16 16 true false false xbrli:decimalItemType decimal The calculated weighted-average amortization period of a major class of finite-lived intangible liabilities acquired during the current period either individually or as part of a group of liabilities (in either an asset acquisition or business combination). A major class is composed of intangible liabilities that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. No authoritative reference available. false 53 Contingencies related to casualty and environmental liabilities acquired 4 us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 true true false false 1178000000 1178000000 true false false xbrli:monetaryItemType monetary The amount of liability arising from an inherited contingency (as defined) which has been recognized as of the acquisition date. 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