Commitments, Contingencies, Guarantees, and Others - Schedule of Allocation of Representation and Warranty Reserves (Details) (USD $)	49 Months Ended	12 Months Ended
	Feb. 28, 2009 Subsidiary	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Number of subsidiaries acquired that originated residential mortgage loans	3
Subsidiaries | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		$ 111,000,000,000
Subsidiaries | GSEs and Active Insured Securitizations
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		27,000,000,000
Subsidiaries | Inactive Insured Securitizations and Others
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		84,000,000,000
Subsidiaries | Government-sponsored enterprises (“GSEs”) | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		11,000,000,000
Subsidiaries | Insured Securitizations | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		20,000,000,000
Original principal balance, sold to third party with repurchase requests		16,000,000,000
Original principal balance, sold to third party without repurchase requests		4,000,000,000
Subsidiaries | Uninsured Securitizations | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		48,000,000,000
Subsidiaries | Private Investors | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008		22,000,000,000
Subsidiaries | Representation and Warranty Liability
Loss Contingencies [Line Items]
Reserve liability		731,000,000	1,172,000,000	899,000,000
Loss contingency, range of loss, portion not accrued		2,100,000,000	2,600,000,000
Net realized losses		408,000,000	36,000,000
Subsidiaries | Representation and Warranty Liability | GSEs and Active Insured Securitizations
Loss Contingencies [Line Items]
Reserve liability		499,000,000	965,000,000
Subsidiaries | Representation and Warranty Liability | Inactive Insured Securitizations and Others
Loss Contingencies [Line Items]
Reserve liability		$ 232,000,000	$ 207,000,000