Commitments and Guarantees (Analysis of Indemnification and Repurchase Liability for Asserted and Unasserted Claims) (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Total Indemnification and Repurchase Liability
Loss Contingencies [Line Items]
Reserves, Beginning balance	$ 153,000,000	$ 672,000,000
Reserve adjustments, net	(5,000,000)	75,000,000
Reserves, Ending balance	126,000,000	547,000,000
Total Indemnification and Repurchase Liability | Loan repurchases and private investor settlements [Member]
Loss Contingencies [Line Items]
Losses	(22,000,000)	(200,000,000)
Residential Mortgages [Member]
Loss Contingencies [Line Items]
Repurchase obligations - sold loan portfolios	88,200,000,000	97,100,000,000
Residential Mortgages [Member] | Total Indemnification and Repurchase Liability
Loss Contingencies [Line Items]
Reserves, Beginning balance	131,000,000	614,000,000
Reserve adjustments, net	(17,000,000)	77,000,000
Reserves, Ending balance	101,000,000	523,000,000
Residential Mortgages [Member] | Total Indemnification and Repurchase Liability | Loan repurchases and private investor settlements [Member]
Loss Contingencies [Line Items]
Losses	(13,000,000)	(168,000,000)
Home Equity [Member]
Loss Contingencies [Line Items]
Repurchase obligations - sold loan portfolios	2,700,000,000	3,100,000,000
Prior period reduction of repurchase obligations - sold loan portfolios		700,000,000
Home Equity [Member] | Total Indemnification and Repurchase Liability
Loss Contingencies [Line Items]
Reserves, Beginning balance	22,000,000	58,000,000
Reserve adjustments, net	12,000,000	(2,000,000)
Reserves, Ending balance	25,000,000	24,000,000
Home Equity [Member] | Total Indemnification and Repurchase Liability | Loan repurchases and private investor settlements [Member]
Loss Contingencies [Line Items]
Losses	$ (9,000,000)	$ (32,000,000)