Fair Value (Fair Value Option Gains Losses for Mortgage Loans Held-for-Sale) (Details) (Residential Mortgage Loans - FVO [Member], Net Investment Income [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Residential Mortgage Loans - FVO [Member] | Net Investment Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Instrument-specific credit risk based on changes in credit spreads for non-agency loans and adjustments in individual loan quality	$ (1)	$ 0	$ 0
Other changes in estimated fair value	1	0	0
Total gains (losses) recognized	$ 0	$ 0	$ 0