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 ($)	Successor [Member] USD ($)	Successor [Member] Parent USD ($)	Successor [Member] Members Equity USD ($)	Successor [Member] Accumulated Other Comprehensive Income (Loss) USD ($)
Balance at Dec. 31, 2009		$ 12,798		$ 7,781	$ 13,941	$ (8,428)	$ (496)
Shares, Issued at Dec. 31, 2009			543,416			(202,677)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income, net of tax	183	183		0	224	0	(41)
Common stock dividends, $0.26 per share		(89)		0	(89)	0	0
Restricted stock and stock options expense		8		8	0	0	0
Restricted stock activity			4			0
Excercise of stock options			544			(1)
Exercise of stock options and related tax benefit of $10	(10)	31		31	0	0	0
Purchase of BNSF common stock			0			(1)
Increase (Decrease) in Member's Equity [Roll Forward]
Net contribution from Berkshire Hathaway Inc.									34,495	34,495	0
Cash distributions to Parent	(226)
Comprehensive income, net of tax	183	183		0	224	0	(41)
Balance at Feb. 12, 2010		12,931		7,820	14,076	(8,428)	(537)
Shares, Issued at Feb. 12, 2010			543,964			(202,679)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income, net of tax								2,262	2,262	2,235	27
Increase (Decrease) in Member's Equity [Roll Forward]
Cash distributions to Parent								(1,250)	(1,250)	(1,250)	0
Comprehensive income, net of tax								2,262	2,262	2,235	27
Balance at Dec. 31, 2010									35,507	35,480	27
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income, net of tax								2,742	2,742	2,972	(230)
Increase (Decrease) in Member's Equity [Roll Forward]
Cash distributions to Parent								(3,500)	(3,500)	(3,500)	0
Comprehensive income, net of tax								2,742	2,742	2,972	(230)
Balance at Dec. 31, 2011								34,749	34,749	34,952	(203)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income, net of tax								3,330	3,330	3,372	(42)
Excercise of stock options								2,552
Increase (Decrease) in Member's Equity [Roll Forward]
Cash distributions to Parent								(3,750)	(3,750)	(3,750)	0
Comprehensive income, net of tax								3,330	3,330	3,372	(42)
Balance at Dec. 31, 2012								$ 34,329	$ 34,329	$ 34,574	$ (245)