Finance Receivables and Loans, Net (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	$ 3,301	$ 3,152	$ 3,267	$ 3,283
Charge-offs	(331)	(197)	(632)	(505)
Recoveries	178	203	346	393
Net charge-offs	(153)	6	(286)	(112)
Provision for credit losses	302	(32)	469	(45)
Other	0	0	0
Allowance, ending balance	3,450	3,126	3,450	3,126
Unfunded Loan Commitment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Provision for credit losses	2		2
Consumer | Automotive
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	2,763	2,809	2,769	2,902
Charge-offs	(277)	(183)	(553)	(467)
Recoveries	169	188	332	375
Net charge-offs	(108)	5	(221)	(92)
Provision for credit losses	230	(12)	337	(8)
Other	0	0	0
Allowance, ending balance	2,885	2,802	2,885	2,802
Consumer | Mortgage/Real Estate
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	26	26	27	33
Charge-offs	(1)	(2)	(2)	(4)
Recoveries	5	3	8	6
Net charge-offs	4	1	6	2
Provision for credit losses	(3)	(4)	(6)	(11)
Other	(1)	1	(1)
Allowance, ending balance	26	24	26	24
Consumer | Other
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	258	69	221	73
Charge-offs	(27)	(5)	(51)	(13)
Recoveries	3	1	4	1
Net charge-offs	(24)	(4)	(47)	(12)
Provision for credit losses	70	8	129	11
Other	(1)	(1)	0
Allowance, ending balance	303	72	303	72
Finance receivables, fair value	7	8	7	8	$ 7	$ 7	$ 8
Commercial
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	254	248	250	275
Charge-offs	(26)	(7)	(26)	(21)
Recoveries	1	11	2	11
Net charge-offs	(25)	4	(24)	(10)
Provision for credit losses	5	(24)	9	(37)
Other	2	0	1
Allowance, ending balance	$ 236	$ 228	$ 236	$ 228