Finance Receivables and Loans, Net (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	$ 3,450	$ 3,126	$ 3,267	$ 3,283
Charge-offs	(447)	(218)	(1,079)	(723)
Recoveries	171	164	517	557
Net charge-offs	(276)	(54)	(562)	(166)
Provision for credit losses	438	76	907	31
Other	(1)		(1)
Allowance, ending balance	3,611	3,148	3,611	3,148
Unfunded Loan Commitment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			2
Consumer | Automotive
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	2,885	2,802	2,769	2,902
Charge-offs	(381)	(211)	(934)	(678)
Recoveries	164	160	496	535
Net charge-offs	(217)	(51)	(438)	(143)
Provision for credit losses	326	59	663	51
Other	(1)		(1)
Allowance, ending balance	2,993	2,810	2,993	2,810
Consumer | Consumer mortgage
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	26	24	27	33
Charge-offs	(1)	(2)	(3)	(6)
Recoveries	2	4	10	10
Net charge-offs	1	2	7	4
Provision for credit losses	(1)	(1)	(7)	(12)
Other	1		0
Allowance, ending balance	27	25	27	25
Consumer | Other
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	303	72	221	73
Charge-offs	(33)	(5)	(84)	(18)
Recoveries	4	0	8	1
Net charge-offs	(29)	(5)	(76)	(17)
Provision for credit losses	99	19	228	30
Other	(1)		(1)
Allowance, ending balance	372	86	372	86
Fair value, option, carrying amount, financing receivable, no allowance	6	8	6	8	$ 7	$ 7	$ 8	$ 8
Fair value, option, carrying amount, financing receivable	6		6			$ 7
Commercial
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	236	228	250	275
Charge-offs	(32)	0	(58)	(21)
Recoveries	1	0	3	11
Net charge-offs	(31)	0	(55)	(10)
Provision for credit losses	14	(1)	23	(38)
Other	0		1
Allowance, ending balance	$ 219	$ 227	$ 219	$ 227