Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 1,497	$ 1,568
Loans held-for-sale, net	235	158
Finance receivables and loans, net	124,894	126,968
Deposit liabilities	122,324	120,752
Short-term borrowings	9,493	5,531
Long-term debt	31,066	34,027
Reported value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,497	1,568
Loans held-for-sale, net	167	128
Finance receivables and loans, net	124,884	126,957
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,242	1,150
Deposit liabilities	61,333	60,146
Short-term borrowings	9,493	5,531
Long-term debt	31,066	34,027
Estimate of fair value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,580	1,600
Loans held-for-sale, net	167	128
Finance receivables and loans, net	129,594	130,837
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,242	1,150
Deposit liabilities	62,368	60,678
Short-term borrowings	9,494	5,532
Long-term debt	32,164	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	1,580	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	1,242	1,150
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	18,316	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	167	128
Finance receivables and loans, net	129,594	130,837
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	0	0
Deposit liabilities	62,368	60,678
Short-term borrowings	9,494	5,532
Long-term debt	$ 13,848	$ 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 Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock.

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