Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Change in amortization of accumulated actuarial losses, net of tax expense/(benefit)	$ 2	$ 0
Change in fuel hedge mark-to-market, net of tax expense/(benefit)	$ (4)	$ 25

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.

No definition available.

Name:	bni_ChangeInUnrecognizedPriorServiceCreditAndActuarialLossesTaxBenefitExpense
Namespace Prefix:	bni_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration