Income Taxes (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes.
Undistributed earnings of foreign subsidiaries	$ 1,123
Unrecognized tax benefits that affect our effective tax rate if recognized	152
Reconciliation of unrecognized tax benefits
Unrecognized tax benefits balance at January 1	132	139	103
Gross increase for tax positions of prior years	4	0	3
Gross decrease for tax positions of prior years	0	0	(1)
Gross increase for tax positions of current year	65	21	35
Settlements	0	(16)	0
Lapse of statute of limitations	(47)	(12)	(1)
Unrecognized tax benefits balance at December 31	154	132	139
Income tax liabilities, non-current	146	111
Accrued interest and penalties related to uncertain tax positions	12	11
Interest expense related to uncertain tax positions	1	3	6
Reduction in previously unrecognized tax benefits within next twelve months	$ 16