Consolidated Statements of Changes in Equity (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Predecessor [Member] USD ($)	Predecessor [Member] Parent USD ($)	Predecessor [Member] Common Stock [Member]	Predecessor [Member] Common Stock Including Additional Paid in Capital [Member] USD ($)	Predecessor [Member] Retained Earnings [Member] USD ($)	Predecessor [Member] Treasury Stock [Member] USD ($)	Predecessor [Member] Accumulated Other Comprehensive Income (Loss) USD ($)	Successor USD ($)	Successor Parent USD ($)	Successor Member's Equity USD ($)	Successor Accumulated Other Comprehensive Income (Loss) USD ($)
Balance, Shares, Value at Dec. 31, 2008		$ 11,131		$ 7,636	$ 12,764	$ (8,395)	$ (874)
Balance, Shares, Issued at Dec. 31, 2008			541,346			(202,165)
Comprehensive income:
Net income	1,721	1,721			1,721
Change in unrecognized prior service credit and actuarial losses, net of tax expense/(benefit)	(13)	24					24
Change in fuel hedge mark-to-market, net of tax expense/(benefit)		327					327
Recognized loss on derivative instruments discontinued hedges, net of tax expense/(benefit)		27					27
Total comprehensive income		2,099		0	1,721	0	378
Common Stock Dividends		(544)		0	(544)
Restricted stock and stock options expense		38		38
Restricted Stock Activity Shares			43			1
Restricted Stock Activity Value		2		2
Exercise of stock options and related tax benefit, shares			2,027			(267)
Exercise of stock options and related tax expense/(benefit), value	(29)	88		105		(17)
Purchase of BNSF Common Stock, Shares			0			(246)
Purchase of BNSF Common Stock, Value		(16)		0		(16)
Balance, Shares, Value at Dec. 31, 2009		12,798		7,781	13,941	(8,428)	(496)
Balance, Shares, Issued at Dec. 31, 2009			543,416			(202,677)
NetContribution									34,495	34,495	0
Comprehensive income:
Net income	224	224			224
Change in unrecognized prior service credit and actuarial losses, net of tax expense/(benefit)	(1)	2					2
Change in fuel hedge mark-to-market, net of tax expense/(benefit)		(45)					(45)
Change In Other Comprehensive Income Of Equity Method Investees		2					2
Total comprehensive income		183		0	224	0	(41)
Common Stock Dividends		(89)			(89)
Restricted stock and stock options expense		8		8
Restricted Stock Activity Shares			4
Restricted Stock Activity Value		0
Exercise of stock options and related tax benefit, shares			544			(1)
Exercise of stock options and related tax expense/(benefit), value	(10)	31		31
Purchase of BNSF Common Stock, Shares			0			(1)
Purchase of BNSF Common Stock, Value		0
Balance, Shares, Value at Feb. 12, 2010		12,931		7,820	14,076	(8,428)	(537)
Balance, Shares, Issued at Feb. 12, 2010			543,964			(202,679)
Comprehensive income:
Net income								2,235	2,235	2,235	0
Change in unrecognized prior service credit and actuarial losses, net of tax expense/(benefit)								8	(13)		(13)
Change in fuel hedge mark-to-market, net of tax expense/(benefit)									41		41
Change In Other Comprehensive Income Of Equity Method Investees									(1)		(1)
Total comprehensive income									2,262	2,235	27
Cash distributions to Parent									(1,250)	(1,250)	0
Balance, Shares, Value at Dec. 31, 2010								35,507	35,507	35,480	27
Comprehensive income:
Net income								2,972	2,972	2,972
Change in unrecognized prior service credit and actuarial losses, net of tax expense/(benefit)								125	(200)		(200)
Change in fuel hedge mark-to-market, net of tax expense/(benefit)									(30)		(30)
Total comprehensive income									2,742	2,972	(230)
Cash distributions to Parent									(3,500)	(3,500)	0
Balance, Shares, Value at Dec. 31, 2011								$ 34,749	$ 34,749	$ 34,952	$ (203)