CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement of Other Comprehensive Income [Abstract]
Net income	$ 53	$ 1,000	$ 606
Other comprehensive income (loss):
Foreign currency translation adjustment	9	0	(6)
Unrealized gain on available-for-sale investments, net of tax	1	0	0
Unrealized loss on derivatives arising during period, net of tax	(2)	0	0
Comprehensive income	$ 61	$ 1,000	$ 600