Significant Accounting Policies (Schedule of Components of Accumulated Other Comprehensive Gain (Loss)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012
Unrealized gains (losses) on securities, beginning balance	$ 2	$ 4
Unrealized gains (losses) on securities, other comprehensive gain/loss	(2)	(2)	2
Unrealized gains (losses) on securities, ending balance		2	4
Unfunded pension gains (losses), beginning balance	(44)	(23)		(3)
Unfunded pension gains (losses), other comprehensive gain/loss	12	(21)	17
Unfunded pension gains (losses), ending balance	(32)	(44)	(23)	(3)
Foreign currency translation adjustments, beginning balance	196	277
Foreign currency translation adjustment, other comprehensive gains/loss	(20)	(81)	74
Foreign currency translation adjustments, ending balance	176	196	277
Accumulated other comprehensive income gain (loss), beginning balance	154	258
Accumulated other comprehensive gain (loss), other comprehensive gain/loss	(10)	(104)
Accumulated other comprehensive income gain (loss), ending balance	$ 144	$ 154	$ 258