Business Segments - Reconciliation of Group Reporting Basis Segment Results (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting [Line Items]
Net Interest Income	$ (134)	$ (254)	$ (643)
Other Revenues	97	54	966
Provision For Credit Losses	185	(398)	(732)
Total Costs and Expenses	52	5	67
Profit (Loss) Before Tax	(274)	193	988
Receivables	(9,339)	(853)	(2,644)
Total Assets	(1,336)	(1,069)	(1,796)
Derivatives and hedge accounting
Segment Reporting [Line Items]
Net Interest Income	2	2	5
Other Revenues	0	0	0
Provision For Credit Losses	0	0	0
Total Costs and Expenses	0	0	0
Profit (Loss) Before Tax	2	2	5
Receivables	0	0	0
Total Assets	(6)	(6)	(6)
Purchase accounting
Segment Reporting [Line Items]
Net Interest Income	0	3	0
Other Revenues	(15)	(5)	16
Provision For Credit Losses	18	(8)	43
Total Costs and Expenses	0	0	0
Profit (Loss) Before Tax	(33)	6	(27)
Receivables	18	33	35
Total Assets	11	32	29
Deferred loan origination costs and premiums
Segment Reporting [Line Items]
Net Interest Income	(21)	(17)	(15)
Other Revenues	0	0	4
Provision For Credit Losses	0	0	0
Total Costs and Expenses	0	0	0
Profit (Loss) Before Tax	(21)	(17)	(11)
Receivables	50	81	97
Total Assets	37	51	63
Credit loss impairment provisioning
Segment Reporting [Line Items]
Net Interest Income	(132)	(243)	(649)
Other Revenues	0	0	250
Provision For Credit Losses	72	(36)	(110)
Total Costs and Expenses	0	0	0
Profit (Loss) Before Tax	(204)	(207)	(289)
Receivables	(1,087)	(1,088)	(911)
Total Assets	(906)	(842)	(719)
Loans held for sale
Segment Reporting [Line Items]
Net Interest Income	14	3	4
Other Revenues	95	76	671
Provision For Credit Losses	95	(354)	(665)
Total Costs and Expenses	1	0	(5)
Profit (Loss) Before Tax	13	433	1,345
Receivables	(8,325)	116	(1,871)
Total Assets	320	367	94
Interest recognition
Segment Reporting [Line Items]
Net Interest Income	0	(5)	9
Other Revenues	0	0	8
Provision For Credit Losses	0	0	0
Total Costs and Expenses	0	0	0
Profit (Loss) Before Tax	0	(5)	17
Receivables	5	6	7
Total Assets	23	23	27
Other
Segment Reporting [Line Items]
Net Interest Income	3	3	3
Other Revenues	17	(17)	17
Provision For Credit Losses	0	0	0
Total Costs and Expenses	51	5	72
Profit (Loss) Before Tax	(31)	(19)	(52)
Receivables	0	(1)	(1)
Total Assets	$ (815)	$ (694)	$ (1,284)