Commitments, Contingencies, Guarantees, and Others - Schedule of Open Claims in Pipeline (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Increase (Decrease) In Unresolved Repurchase Claims Face Amount	$ 847
Subsidiaries
Unresolved Repurchase Claims [Roll Forward]
Open claims, beginning balance	2,512	$ 2,825
Gross new demands received	43	764
Loans repurchased/made whole	(15)	(36)
Demands rescinded	(875)	(1,041)
Open claims, ending balance	1,665	2,512
Subsidiaries | Government-sponsored enterprises (“GSEs”)
Unresolved Repurchase Claims [Roll Forward]
Open claims, beginning balance	16	89
Gross new demands received	21	22
Loans repurchased/made whole	(14)	(31)
Demands rescinded	(15)	(64)
Open claims, ending balance	8	16
Subsidiaries | Insured Securitizations
Unresolved Repurchase Claims [Roll Forward]
Open claims, beginning balance	649	1,614
Gross new demands received	0	0
Loans repurchased/made whole	0	0
Demands rescinded	(106)	(965)
Open claims, ending balance	543	649
Subsidiaries | Uninsured Securitizations and Other
Unresolved Repurchase Claims [Roll Forward]
Open claims, beginning balance	1,847	1,122
Gross new demands received	22	742
Loans repurchased/made whole	(1)	(5)
Demands rescinded	(754)	(12)
Open claims, ending balance	$ 1,114	$ 1,847