Finance Receivables And Loans, Net (Past Due Financing Receivables And Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 2,414	$ 2,031
Current	109,186	97,916
Finance receivables and loans, net	111,600	99,948
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	111,600	99,947
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,715	1,416
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	394	327
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	305	288
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,209	1,797
Current	62,083	54,773
Finance receivables and loans, net	64,292	56,570
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election		56,570
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	205	225
Current	9,568	7,248
Finance receivables and loans, net	9,773	7,474
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election		7,473
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,618	1,340
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	97	76
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	369	293
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	25	25
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	222	164
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	83	124
Commercial Portfolio Segment [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	9
Current	37,535	35,895
Finance receivables and loans, net	37,535	35,904
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election		35,904
Commercial Portfolio Segment [Member] | Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	9
Current	31,469	30,862
Finance receivables and loans, net	31,469	30,871
Commercial Portfolio Segment [Member] | Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Current	2,640	1,882
Finance receivables and loans, net	2,640	1,882
Commercial Portfolio Segment [Member] | Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Current	3,426	3,151
Finance receivables and loans, net	3,426	3,151
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	9
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	9
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 0	$ 0