Receivables Held For Sale - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 86	$ 0	$ 13	$ 0
Initial valuation allowance for real estate secured receivables transferred to held for sale during the period	2	0	6	0
Increase in valuation allowance resulting from changes in fair value	62	53	130	53
Change in valuation allowance for receivables sold	0	(21)	0	(21)
Change in valuation allowance for collections, charged-off, transferred to REO or short sale	0	1	1	1
Balance at end of period	$ 150	$ 33	$ 150	$ 33