Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 1,253	$ 1,568
Loans held-for-sale, net	406	158
Finance receivables and loans, net	115,251	126,968
Deposit liabilities	137,036	120,752
Short-term borrowings	2,136	5,531
Long-term debt	22,006	34,027
Reported value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,253	1,568
Loans held-for-sale, net	315	128
Finance receivables and loans, net	115,243	126,957
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	725	1,150
Deposit liabilities	55,210	60,146
Short-term borrowings	2,136	5,531
Long-term debt	22,006	34,027
Estimate of fair value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,331	1,600
Loans held-for-sale, net	315	128
Finance receivables and loans, net	122,156	130,837
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	725	1,150
Deposit liabilities	55,932	60,678
Short-term borrowings	2,136	5,532
Long-term debt	25,471	36,927
Estimate of fair value measurement \| Fair value, inputs, level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0	0
Loans held-for-sale, net	0	0
Finance receivables and loans, net	0	0
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	0	0
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Estimate of fair value measurement \| Fair value, inputs, level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,331	1,600
Loans held-for-sale, net	0	0
Finance receivables and loans, net	0	0
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	725	1,150
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	19,161	22,789
Estimate of fair value measurement \| Fair value, inputs, level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0	0
Loans held-for-sale, net	315	128
Finance receivables and loans, net	122,156	130,837
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	0	0
Deposit liabilities	55,932	60,678
Short-term borrowings	2,136	5,532
Long-term debt	$ 6,310	$ 14,138

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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Amount of investment in debt security measured at amortized cost (held-to-maturity).

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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