Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated other comprehensive income (loss) [Line Items]
Accumulated other comprehensive income (loss), balance at beginning of period	$ (26,000,000)	$ (72,000,000)
Other comprehensive income (loss) before reclassifications	(69,000,000)	39,000,000
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Accumulated other comprehensive income (loss), balance at end of period	(95,000,000)	(33,000,000)
Foreign currency translation adjustment
Accumulated other comprehensive income (loss) [Line Items]
Accumulated other comprehensive income (loss), balance at beginning of period	(26,000,000)	(72,000,000)
Other comprehensive income (loss) before reclassifications	(70,000,000)	38,000,000
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Accumulated other comprehensive income (loss), balance at end of period	(96,000,000)	(34,000,000)
Unrealized gain on available-for-sale securities
Accumulated other comprehensive income (loss) [Line Items]
Accumulated other comprehensive income (loss), balance at beginning of period	0	0
Other comprehensive income (loss) before reclassifications	1,000,000	1,000,000
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Accumulated other comprehensive income (loss), balance at end of period	$ 1,000,000	$ 1,000,000