Securitizations and Variable Interest Entities (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Variable Interest Entity [Line Items]
Carrying value of total assets	$ 188,640	$ 182,114	$ 179,184
Carrying value of total liabilities	176,206	165,064
Non-recourse debt	16,628	17,029
Other assets	9,343	8,057
On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Carrying value of total assets	9,109	7,509
Carrying value of total liabilities	1,270	1,339
Non-recourse debt	1,267	1,337
Other assets	695	563
On-balance sheet variable interest entities | Consumer | Consumer automotive
Variable Interest Entity [Line Items]
Carrying value of total assets	19,793	18,158
Carrying value of total liabilities	1,384	1,162
Assets sold to nonconsolidated VIEs	0	0
Maximum exposure to loss in nonconsolidated VIEs	0	0
Assets held-in-trust	10,700	11,000
On-balance sheet variable interest entities | Consumer | Consumer automotive | Nonrecourse
Variable Interest Entity [Line Items]
Non-recourse debt	114	124
On-balance sheet variable interest entities | Consumer | Other
Variable Interest Entity [Line Items]
Carrying value of total assets		318
Carrying value of total liabilities		300
Assets sold to nonconsolidated VIEs		0
Maximum exposure to loss in nonconsolidated VIEs		0
Off-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Carrying value of total assets	21,874	20,290
Carrying value of total liabilities	2,225	2,188
Assets sold to nonconsolidated VIEs	133	0
Maximum exposure to loss in nonconsolidated VIEs	2,773	2,416
Off-balance sheet variable interest entities | Consumer | Consumer automotive
Variable Interest Entity [Line Items]
Carrying value of total assets	0
Carrying value of total liabilities	0
Assets sold to nonconsolidated VIEs	57
Maximum exposure to loss in nonconsolidated VIEs	57
Off-balance sheet variable interest entities | Consumer | Other
Variable Interest Entity [Line Items]
Carrying value of total assets	0
Carrying value of total liabilities	0
Assets sold to nonconsolidated VIEs	76
Maximum exposure to loss in nonconsolidated VIEs	76
Off-balance sheet variable interest entities | Commercial | Other
Variable Interest Entity [Line Items]
Carrying value of total assets	2,081	1,814
Carrying value of total liabilities	841	726
Assets sold to nonconsolidated VIEs	0	0
Maximum exposure to loss in nonconsolidated VIEs	2,640	2,416
Other assets	$ 1	$ 8