Commitments, Contingencies, Guarantees, and Others - Schedule of Changes in Representation and Warranty Reserve (Details) - Subsidiaries - Representation and Warranty Liability [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Loss Contingency Accrual [Roll Forward]
Representation and warranty repurchase reserve, beginning of period	$ 516	$ 613	$ 630	$ 610
Provision (benefit) for mortgage representation and warranty losses	6	1	(86)	3
Net realized losses	(1)	0	(23)	1
Representation and warranty repurchase reserve, end of period	521	614	521	614
Continuing Operations
Loss Contingency Accrual [Roll Forward]
Provision (benefit) for mortgage representation and warranty losses	0	(1)	(25)	(2)
Discontinued Operations
Loss Contingency Accrual [Roll Forward]
Provision (benefit) for mortgage representation and warranty losses	$ 6	$ 2	$ (61)	$ 5