Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Income tax
Net UTB impacting the effective tax rate	$ 210		$ 210		$ 295
Period discussed over which uncertain tax positions could include material unrecognized tax benefits due to the closing of various audit years	12 months
Interest and penalties related to unrecognized tax benefits, expense (benefit) recognized on a gross basis	(3)	(3)	(8)
Interest and penalties related to unrecognized tax benefits, accrued on a gross basis	48		48		56
Deferred tax assets valuation allowance	$ 31		$ 31		$ 82
Reconciliation of Effective Income Tax Rate
Effective tax rate (as a percent)	28.20%	28.60%	29.00%	28.10%
Change in effective income tax rate from prior reporting period to current reporting period (as a percent)	(0.40%)		0.90%
Change in effective tax rate from prior reporting period to current reporting period primarily due to international taxes for corporate reorganization of subsidiary and lapse of research development credit (as a percent)	2.50%		1.60%
Change in effective income tax rate from prior reporting period to current reporting period due to international tax geographic mix and benefits from certain realized credits and adjustments to tax reserves (as a percent)	(2.90%)		(0.70%)