Commitments, Contingencies, Guarantees, and Others - Schedule of Allocation of Representation and Warranty Reserves (Details) $ in Millions	3 Months Ended		49 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Feb. 28, 2009 Subsidiary	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Number of subsidiaries acquired that originated residential mortgage loans | Subsidiary			3
Subsidiaries | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008	$ 111,000
Subsidiaries | Government-sponsored enterprises (“GSEs”) | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008	11,000
Subsidiaries | Insured Securitizations | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008	20,000
Original principal balance, sold to third party with repurchase requests	16,000
Original principal balance, sold to third party without repurchase requests	4,000
Subsidiaries | Uninsured Securitizations | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008	48,000
Subsidiaries | Private Investors | 2005 to 2008 Year
Loss Contingencies [Line Items]
Loans sold 2005 to 2008	22,000
Subsidiaries | Representation and Warranty Liability [Member]
Loss Contingencies [Line Items]
Loss contingency accrual	516	$ 613		$ 630	$ 610
Loss Contingency Accrual, Provision	(92)	2
Net realized losses	(22)	1
Loss Contingency, Range of Possible Loss, Portion Not Accrued	1,400			$ 1,500
Continuing Operations | Subsidiaries | Representation and Warranty Liability [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, Provision	(25)	(1)
Discontinued Operations | Subsidiaries | Representation and Warranty Liability [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, Provision	$ (67)	$ 3