Goodwill and Other Intangible Assets (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amortization expense and projected amortization expense for intangible assets
Amortization of intangibles	$ 48	$ 33	$ 21
Expected amortization expense, 2013	51
Expected amortization expense, 2014	52
Expected amortization expense, 2015	49
Expected amortization expense, 2016	49
Expected amortization expense, 2017	$ 46