Receivables Held for Sale - Summary of Secured Receivables Transferred to REO or the Underlying Collateral Sold in a Short Sale (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Carrying value of real estate secured receivables held for sale settled through short sale or transfer to REO	$ (148)	$ (243)	$ (711)
Impact to lower of amortized cost or FV adjustment previously recorded resulting from the transfer to REO or short sales	130	(314)	(748)
Transferred to REO after obtaining title to the underlying collateral [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Carrying value of real estate secured receivables held for sale settled through short sale or transfer to REO	93	182	529
Impact to lower of amortized cost or FV adjustment previously recorded resulting from the transfer to REO or short sales	(1)	5	(40)
Underlying collateral sold in a short sale [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Carrying value of real estate secured receivables held for sale settled through short sale or transfer to REO	55	61	182
Impact to lower of amortized cost or FV adjustment previously recorded resulting from the transfer to REO or short sales	$ 2	$ 3	$ (22)