Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in Pension and Retiree Health and Welfare benefits, net of tax (benefit) / expense	$ (156)	$ 305	$ (16)
Change in fuel hedge mark-to-market, net of tax expense/(benefit)	$ 0	$ 0	$ (7)

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.

No definition available.

Name:	bni_FuelInterestHedgeMarkToMarketTaxBenefitExpense
Namespace Prefix:	bni_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration