Commitments and Guarantees (Analysis of Indemnification and Repurchase Liability for Asserted and Unasserted Claims) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Total Indemnification and Repurchase Liability
Loss Contingencies [Line Items]
Reserves, Beginning balance	$ 153,000,000	$ 672,000,000
Reserve adjustments, net	10,000,000	69,000,000
Reserves, Ending balance	132,000,000	494,000,000
Total Indemnification and Repurchase Liability | Loan repurchases and private investor settlements [Member]
Loss Contingencies [Line Items]
Losses	(31,000,000)	(247,000,000)
Residential Mortgages [Member]
Loss Contingencies [Line Items]
Repurchase obligations - sold loan portfolios	86,100,000,000	97,900,000,000
Residential Mortgages [Member] | Total Indemnification and Repurchase Liability
Loss Contingencies [Line Items]
Reserves, Beginning balance	131,000,000	614,000,000
Reserve adjustments, net	(4,000,000)	71,000,000
Reserves, Ending balance	108,000,000	471,000,000
Residential Mortgages [Member] | Total Indemnification and Repurchase Liability | Loan repurchases and private investor settlements [Member]
Loss Contingencies [Line Items]
Losses	(19,000,000)	(214,000,000)
Home Equity [Member]
Loss Contingencies [Line Items]
Repurchase obligations - sold loan portfolios	2,600,000,000	2,900,000,000
Prior Period Reduction For Correction Of Error		800,000,000
Home Equity [Member] | Total Indemnification and Repurchase Liability
Loss Contingencies [Line Items]
Reserves, Beginning balance	22,000,000	58,000,000
Reserve adjustments, net	14,000,000	(2,000,000)
Reserves, Ending balance	24,000,000	23,000,000
Home Equity [Member] | Total Indemnification and Repurchase Liability | Loan repurchases and private investor settlements [Member]
Loss Contingencies [Line Items]
Losses	$ (12,000,000)	$ (33,000,000)