Employment Benefit Plans Other Details (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Description of 401(k) plans and non-qualified defined contribution plan	BNSF sponsors qualified 401(k) plans that cover substantially all employees and a non-qualified defined contribution plan that covers certain officers and other employees. BNSF matched 75 percent of the first six percent of non-union employees’ contributions and matched 25 percent on the first four percent of a limited number of union employees’ contributions, which are subject to certain percentage limits of the employees’ earnings, at each pay period. Employer contributions are subject to a five-year length of service vesting schedule.
401(k) matching expense	$ 36	$ 34	$ 32
Collective bargaining agreements description	Under collective bargaining agreements, BNSF participates in multi-employer benefit plans that provide certain postretirement health care and life insurance benefits for eligible union employees. Insurance premiums paid attributable to retirees, which are generally expensed as incurred
Multiemployer Plan, insurance premiums	65	65	71
Average number of employees covered under multi-employer benefit plans	40,000	37,000	36,000
Funded Pension Plan [Member] | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	1
Unfunded Non-Qualified Pension Plan [Member] | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 9