Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Change in amortization of accumulated actuarial losses, net of tax expense	$ 2	$ 0	$ 4	$ 2
Change in fuel hedge mark-to-market, net of tax expense/(benefit)	$ 0	$ (2)	$ 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