Goodwill and Other Intangible Assets - Key Economic Assumptions (Details 6) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Weighted-average prepayment speed assumption (CPR)	8.07%	13.04%
Impact on fair value of 10% adverse change	$ (362)	$ (517)
Impact on fair value of 20% adverse change	(705)	(1,009)
Weighted-average option adjusted spread	7.77%	7.61%
Impact on fair value of 100 basis points adverse change	(389)	(306)
Impact on fair value of 200 basis points adverse change	$ (750)	$ (591)