Commitments and Contingencies - Personal Injury (Details) (USD $) In Millions, unless otherwise specified					6 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2013 Unasserted Claim	Jun. 30, 2013 Personal Injury	Jun. 30, 2012 Personal Injury	Jun. 30, 2013 Personal Injury	Jun. 30, 2012 Personal Injury	Jun. 30, 2013 Bank Time Deposits and Money Market Funds BNSF Insurance Company	Dec. 31, 2012 Bank Time Deposits and Money Market Funds BNSF Insurance Company	Jun. 30, 2013 Current Liabilities [Member]
Asbestos and Personal Injury [Abstract]
Percent of future unasserted asbestos claims to be filed within the next ten years					60.00%
Percent of future unasserted asbestos claims to be filed within the next fifteen years					80.00%
Percent of future unasserted asbestos claims to be filed within the next twenty-five years					95.00%
Length in years for 60 percent of future unasserted asbestos claims to be filed					10 years
Length in years for 80 percent of future unasserted asbestos claims to be filed					15 years
Length in years for 95 percent of future unasserted asbestos claims to be filed					25 years
Accrued obligations for asbestos and other personal injury matters, current liabilities												$ 95
Future costs to settle personal injury claims, minimum						420		420
Future costs to settle personal injury claims, maximum						530		530
Loss Contingency Accrual [Roll Forward]
Beginning balance						453	506	462	540
Accruals						29	27	55	50
Payments						(15)	(22)	(50)	(79)
Ending balance						467	511	467	511
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 1,672	$ 1,794	$ 1,718	$ 1,960						$ 465	$ 485