Finance Receivables And Loans, Net (Allowance For Credit Losses On Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	$ 1,077	$ 933	$ 1,054	$ 977
Allowance for Loan and Lease Losses, Write-offs	(237)	(175)	(500)	(390)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	85	75	169	140
Allowance for Loan and Lease Losses Write-offs, Net	(152)	(100)	(331)	(250)
Allowance for Loan and Lease Losses, Provision for Loss, Net	172	140	392	256
Allowance for Loan and Lease Losses, Adjustments, Net	(8)	1	(26)	(9)
Loans and Leases Receivable, Allowance, Ending Balance	1,089	974	1,089	974
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	86	91	86	91
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,003	883	1,003	883
Finance receivables and loans, net	112,653	105,172	112,653	105,172	$ 111,600
Financing Receivable, Individually Evaluated for Impairment	724	639	724	639
Financing Receivable, Collectively Evaluated for Impairment	111,929	104,533	111,929	104,533
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses	0	0	0	0
Finance receivables and loans, net	0	0	0	0
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	850	711	834	685
Allowance for Loan and Lease Losses, Write-offs	(227)	(166)	(480)	(359)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	79	70	159	131
Allowance for Loan and Lease Losses Write-offs, Net	(148)	(96)	(321)	(228)
Allowance for Loan and Lease Losses, Provision for Loss, Net	168	152	375	310
Allowance for Loan and Lease Losses, Adjustments, Net	(8)	0	(26)	0
Loans and Leases Receivable, Allowance, Ending Balance	862	767	862	767
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	26	22	26	22
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	836	745	836	745
Finance receivables and loans, net	63,281	60,786	63,281	60,786	64,292
Financing Receivable, Individually Evaluated for Impairment	348	275	348	275
Financing Receivable, Collectively Evaluated for Impairment	62,933	60,511	62,933	60,511
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses	0	0	0	0
Finance receivables and loans, net	0	0	0	0
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	115	119	114	152
Allowance for Loan and Lease Losses, Write-offs	(9)	(9)	(19)	(31)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	5	5	9	8
Allowance for Loan and Lease Losses Write-offs, Net	(4)	(4)	(10)	(23)
Allowance for Loan and Lease Losses, Provision for Loss, Net	(2)	3	5	(2)
Allowance for Loan and Lease Losses, Adjustments, Net	0	1	0	(8)
Loans and Leases Receivable, Allowance, Ending Balance	109	119	109	119
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	37	50	37	50
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	72	69	72	69
Finance receivables and loans, net	11,084	9,211	11,084	9,211	9,773
Financing Receivable, Individually Evaluated for Impairment	254	265	254	265
Financing Receivable, Collectively Evaluated for Impairment	10,830	8,946	10,830	8,946
Consumer Portfolio Segment [Member] | Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses	0	0	0	0
Finance receivables and loans, net	0	0	0	0
Commercial Portfolio Segment [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	112	103	106	140
Allowance for Loan and Lease Losses, Write-offs	(1)	0	(1)	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1	0	1	1
Allowance for Loan and Lease Losses Write-offs, Net	0	0	0	1
Allowance for Loan and Lease Losses, Provision for Loss, Net	6	(15)	12	(52)
Allowance for Loan and Lease Losses, Adjustments, Net	0	0	0	(1)
Loans and Leases Receivable, Allowance, Ending Balance	118	88	118	88
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	23	19	23	19
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	95	69	95	69
Finance receivables and loans, net	38,288	35,175	38,288	35,175	$ 37,535
Financing Receivable, Individually Evaluated for Impairment	122	99	122	99
Financing Receivable, Collectively Evaluated for Impairment	38,166	35,076	38,166	35,076
Commercial Portfolio Segment [Member] | Commercial Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Financing Receivable, Allowance for Credit Losses	0	0	0	0
Finance receivables and loans, net	$ 0	$ 0	$ 0	$ 0