Securitizations and Variable Interest Entities (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Carrying value of total assets	$ 182,114	$ 182,165	$ 180,644
Carrying value of total liabilities	165,064	167,462
Other assets	8,057	6,415
On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Carrying value of total assets	7,509	14,196
Carrying value of total liabilities	1,339	4,161
Other assets	563	983
On-balance sheet variable interest entities | Consumer | Automotive loan
Variable Interest Entity [Line Items]
Carrying value of total assets	18,158	17,833
Carrying value of total liabilities	1,162	3,103
Assets sold to nonconsolidated VIEs	0	0
Maximum exposure to loss in nonconsolidated VIEs	0	0
Assets held-in-trust	11,000	9,900
Non-recourse debt	124	94
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
On-balance sheet variable interest entities | Commercial | Automotive loan
Variable Interest Entity [Line Items]
Carrying value of total assets		6,276
Carrying value of total liabilities		1,152
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	20,290	25,404
Carrying value of total liabilities	2,188	4,784
Assets sold to nonconsolidated VIEs	0	0
Maximum exposure to loss in nonconsolidated VIEs	2,416	1,754
Off-balance sheet variable interest entities | Commercial | Other
Variable Interest Entity [Line Items]
Carrying value of total assets	1,814	1,295
Carrying value of total liabilities	726	529
Assets sold to nonconsolidated VIEs	0	0
Maximum exposure to loss in nonconsolidated VIEs	2,416	$ 1,754
Other assets	$ 8