Consolidated Statement of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Unrealized gains (losses) on marketable securities, deferred taxes	$ (2)	$ 0	$ (4)
Deferred gains (losses) on cash flow hedges, deferred taxes	15	47	0
Realized (gains) losses on marketable securities, deferred taxes	5	2	2
Realized (gains) losses on cash flow hedges, deferred taxes	(11)	(21)	(20)
Employee benefit obligations, deferred taxes	22	9	(15)
Currency translation adjustments, deferred taxes	$ 3	$ 0	$ 0