Receivables Held For Sale - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 150	$ 33	$ 13	$ 0
Initial valuation allowance for real estate secured receivables transferred to held for sale during the period	5	0	11	0
Increase in valuation allowance resulting from changes in fair value	15	84	145	137
Change in valuation allowance for receivables sold	(81)	(33)	(81)	(54)
Change in valuation allowance for collections, charged-off, transferred to REO or short sale	(1)	0	0	1
Balance at end of period	$ 88	$ 84	$ 88	$ 84