Restructuring and Other Items (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	$ 242	$ 450	$ 407
Facilities and Fleet [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	135	202	13
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	100	15	119
Impairment of Intangible Assets [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	50	0	0
Gain on Divestiture of Slot Swaps [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	(43)	0	0
Merger Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	$ 0	$ 233	$ 275