Finance Receivables And Loans, Net (Allowance For Credit Losses On Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	$ 974	$ 1,171	$ 977	$ 1,208
Allowance for Loan and Lease Losses, Write-offs	(231)	(201)	(621)	(554)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	70	52	210	187
Allowance for Loan and Lease Losses Write-offs, Net	(161)	(149)	(411)	(367)
Allowance for Loan and Lease Losses, Provision for Loss, Net	211	102	467	302
Allowance for Loan and Lease Losses, Adjustments, Net	(6)	(11)	(15)	(30)
Loans and Leases Receivable, Allowance, Ending Balance	1,018	1,113	1,018	1,113
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, Individually evaluated for impairment	89	220	89	220
Allowance for loan losses, Collectively evaluated for impairment	929	893	929	893
Finance receivables and loans, net	107,991		107,991		$ 99,948
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	107,990	99,517	107,990	99,517	99,947
Financing Receivable, Individually Evaluated for Impairment	628	1,266	628	1,266
Financing receivable, Collectively evaluated for impairment	107,362	98,249	107,362	98,249
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	2	0	2
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	767	729	685	673
Allowance for Loan and Lease Losses, Write-offs	(220)	(188)	(579)	(511)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	64	51	195	170
Allowance for Loan and Lease Losses Write-offs, Net	(156)	(137)	(384)	(341)
Allowance for Loan and Lease Losses, Provision for Loss, Net	200	112	510	372
Allowance for Loan and Lease Losses, Adjustments, Net	(7)	(11)	(7)	(11)
Loans and Leases Receivable, Allowance, Ending Balance	804	693	804	693
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, Individually evaluated for impairment	22	25	22	25
Allowance for loan losses, Collectively evaluated for impairment	782	668	782	668
Finance receivables and loans, net	63,610		63,610		56,570
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	63,610	58,675	63,610	58,675
Financing Receivable, Individually Evaluated for Impairment	285	289	285	289
Financing receivable, Collectively evaluated for impairment	63,325	58,384	63,325	58,384
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	2	0	2
Consumer Portfolio Segment [Member] \| Residential Mortgage [Member]
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	119	302	152	389
Allowance for Loan and Lease Losses, Write-offs	(10)	(13)	(41)	(38)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	4	1	12	6
Allowance for Loan and Lease Losses Write-offs, Net	(6)	(12)	(29)	(32)
Allowance for Loan and Lease Losses, Provision for Loss, Net	6	(7)	4	(55)
Allowance for Loan and Lease Losses, Adjustments, Net	0	0	(8)	(19)
Loans and Leases Receivable, Allowance, Ending Balance	119	283	119	283
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, Individually evaluated for impairment	48	180	48	180
Allowance for loan losses, Collectively evaluated for impairment	71	103	71	103
Finance receivables and loans, net	9,770		9,770		7,474
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	9,769	7,594	9,769	7,594	7,473
Financing Receivable, Individually Evaluated for Impairment	268	904	268	904
Financing receivable, Collectively evaluated for impairment	9,501	6,690	9,501	6,690
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	88	140	140	146
Allowance for Loan and Lease Losses, Write-offs	(1)	0	(1)	(5)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	2	0	3	11
Allowance for Loan and Lease Losses Write-offs, Net	1	0	2	6
Allowance for Loan and Lease Losses, Provision for Loss, Net	5	(3)	(47)	(15)
Allowance for Loan and Lease Losses, Adjustments, Net	1	0	0	0
Loans and Leases Receivable, Allowance, Ending Balance	95	137	95	137
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, Individually evaluated for impairment	19	15	19	15
Allowance for loan losses, Collectively evaluated for impairment	76	122	76	122
Finance receivables and loans, net	34,611		34,611		$ 35,904
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	34,611	33,248	34,611	33,248
Financing Receivable, Individually Evaluated for Impairment	75	73	75	73
Financing receivable, Collectively evaluated for impairment	34,536	33,175	34,536	33,175
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

Loans and Leases Receivable, Gross, Excluding Fair Value Option Election

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Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of other addition (reduction) in allowance reserve for credit loss.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount, after recoveries, of loans and leases that have been written-off.

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A valuation allowance for financing receivables that are expected to be uncollectible.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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