Consolidated Statement 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	$ 2,609	$ 3,229	$ 1,801
Other comprehensive income (loss), before tax and net of reclassification adjustments:
Foreign currency translation	335	(280)	(176)
Tax (expense) benefit on foreign currency translation	2	0	12
Unrealized gains on investments, net	99	57	117
Tax (expense) benefit on unrealized gains (losses) on investments, net	(6)	(35)	(38)
Unrealized gains (losses) on hedging activities, net	(127)	58	18
Tax (expense) benefit on unrealized gains (losses) on hedging activities, net	4	(1)	(1)
Other comprehensive income (loss), net tax	307	(201)	(68)
Other comprehensive income	$ 2,916	$ 3,028	$ 1,733