Finance Receivables and Loans, Net (Schedule of Financing Receivables, Nonaccrual Status) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	$ 1,283		$ 1,283		$ 1,439	$ 1,522	$ 1,396	$ 1,036
Financing receivable, nonaccrual, with no allowance	584		584			706
Financing receivable, nonaccrual, interest income	3	$ 4	5	$ 6
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,111		1,111		1,270	1,361	1,140	821
Financing receivable, nonaccrual, with no allowance	523		523			650
Consumer | Consumer automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,033		1,033		1,173	1,256	1,077	762
Financing receivable, nonaccrual, with no allowance	472		472			604
Consumer | Consumer mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	76		76		95	102	62	57
Financing receivable, nonaccrual, with no allowance	51		51			46
Consumer | Mortgage Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	49		49		63	67	22	17
Financing receivable, nonaccrual, with no allowance	26		26			18
Consumer | Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	27		27		32	35	40	40
Financing receivable, nonaccrual, with no allowance	25		25			28
Consumer | Consumer other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	2		2		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	172		172		169	161	256	215
Financing receivable, nonaccrual, with no allowance	61		61			56
Commercial | Consumer automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	33		33		17	40	86	73
Financing receivable, nonaccrual, with no allowance	4		4			10
Commercial | Consumer mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	6		6		2	5	8	4
Financing receivable, nonaccrual, with no allowance	6		6			5
Commercial | Consumer other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	133		133		$ 150	116	$ 162	$ 138
Financing receivable, nonaccrual, with no allowance	$ 51		$ 51			$ 41