Goodwill and Other Intangible Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Goodwill and Other Intangible Assets
Aggregate pre-tax amortization expense	$ 106	$ 67
Pre-tax amortization expense, 2012	338
Pre-tax amortization expense, 2013	332
Pre-tax amortization expense, 2014	348
Pre-tax amortization expense, 2015	351
Pre-tax amortization expense, 2016	308
Pre-tax amortization expense, 2017	$ 180