Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified					3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2013 Accumulated Translation Adjustment [Member]	Mar. 31, 2012 Accumulated Translation Adjustment [Member]	Mar. 31, 2013 Accumulated Defined Benefit Plans Adjustment [Member]	Mar. 31, 2012 Accumulated Defined Benefit Plans Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 155	$ 293	$ 410	$ 224
Other comprehensive income (loss), adjustments during the period					(154)	180
Other comprehensive income (loss), adjustments reclassified to income					4	(4)	19	14
Income taxes					0	0	(7)	(4)
Other comprehensive income (loss), net of tax					(150)	176	12	10
Ending balance	$ 155	$ 293	$ 410	$ 224	$ 717	$ 949	$ (562)	$ (539)