Income Taxes Summary of Gross Unrecognized Income Tax Benefits (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Gross Unrecognized Income Tax Benefits [Line Items]
Balance at January 1	$ 224	$ 197	$ 139
Increases and decreases as a result of positions taken during prior years
Transfers to valuation allowances	0	(2)	(1)
Other increases	3	7	37
Other decreases, including foreign currency translation	(14)	(31)	(4)
Balances related to acquired businesses	2	34	5
Increases as a result of positions taken during the current year	31	23	28
Decreases relating to settlements with tax authorities	(2)	0	(4)
Decreases as a result of a lapse of the applicable statute of limitations	(8)	(4)	(3)
Balance at December 31	$ 236	$ 224	$ 197