Securities (Schedule of Credit Losses on Other-than-Temporarily Impaired Non-agency RMBS where Portion of the Unrealized Loss was Recognized in OCI (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Securities
Balance at beginning of period	$ 98	$ 130	$ 31
Credit losses on securities not previously considered other-than-temporarily impaired	0	0	1
Credit losses on securities with previously recognized OTTI	0	5	111
Reductions for securities sold/settled during the period	(20)	(37)	(13)
Balance at end of period	$ 78	$ 98	$ 130