Restructuring and Other Items (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	$ 106	$ 149	$ 242	$ 330
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	0	66	0	237
Facilities and Fleet [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	106	122	242	171
Gain on Slot Exchange [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	$ 0	$ (39)	$ 0	$ (78)