Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 1,568	$ 2,362
Loans held-for-sale, net	158	314
Finance receivables and loans, net	126,968	128,684
Deposit liabilities	120,752	106,178
Short-term borrowings	5,531	9,987
Long-term debt	34,027	44,193
Reported value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,568	2,362
Loans held-for-sale, net	128	306
Finance receivables and loans, net	126,957	128,684
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,150	1,351
Deposit liabilities	60,146	51,985
Short-term borrowings	5,531	9,987
Long-term debt	34,027	44,193
Estimate of fair value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,600	2,307
Loans held-for-sale, net	128	306
Finance receivables and loans, net	130,837	130,878
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,150	1,351
Deposit liabilities	60,678	51,997
Short-term borrowings	5,532	9,992
Long-term debt	36,927	45,646
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	1,600	2,307
Loans held-for-sale, net	0	0
Finance receivables and loans, net	0	0
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,150	1,351
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	22,789	23,846
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	128	306
Finance receivables and loans, net	130,837	130,878
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	0	0
Deposit liabilities	60,678	51,997
Short-term borrowings	5,532	9,992
Long-term debt	$ 14,138	$ 21,800

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 Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock.

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