Accounts Payable and Other Current Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts Payable and Other Current Liablities [Line Items]
Compensation and benefits payable	$ 821	$ 673
Accounts payable	311	310
Property and income tax liabilities	290	541
Accrued interest	243	208
Rents and leases	161	168
Customer incentives	151	155
Casualty and environmental liabilities	145	170
Other	1,084	895
Total	$ 3,206	$ 3,120