Finance Receivables and Loans, Net (Schedule of Financing Receivables, Nonaccrual Status) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	$ 1,285		$ 1,285		$ 1,283	$ 1,522	$ 1,532	$ 1,036
Financing receivable, nonaccrual, with no allowance	549		549			706
Financing receivable, nonaccrual, interest income	2	$ 2	7	$ 8
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,087		1,087		1,111	1,361	1,314	821
Financing receivable, nonaccrual, with no allowance	481		481			650
Consumer | Automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,015		1,015		1,033	1,256	1,250	762
Financing receivable, nonaccrual, with no allowance	432		432			604
Consumer | Mortgage/Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	69		69		76	102	63	57
Financing receivable, nonaccrual, with no allowance	49		49			46
Consumer | Mortgage Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	45		45		49	67	27	17
Financing receivable, nonaccrual, with no allowance	27		27			18
Consumer | Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	24		24		27	35	36	40
Financing receivable, nonaccrual, with no allowance	22		22			28
Consumer | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	3		3		2	3	1	2
Financing receivable, nonaccrual, with no allowance	0		0			0
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	198		198		172	161	218	215
Financing receivable, nonaccrual, with no allowance	68		68			56
Commercial | Automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	32		32		33	40	80	73
Financing receivable, nonaccrual, with no allowance	3		3			10
Commercial | Mortgage/Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	3		3		6	5	6	4
Financing receivable, nonaccrual, with no allowance	3		3			5
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	163		163		$ 133	116	$ 132	$ 138
Financing receivable, nonaccrual, with no allowance	$ 62		$ 62			$ 41