Fair Value (Fair Value, by Balance Sheet Grouping) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 4,680	$ 1,062
Loans held-for-sale, net	400	654
Finance receivables and loans, net	135,852	132,037
Deposit liabilities	154,666	152,297
Short-term borrowings	3,297	2,399
Long-term debt	17,570	17,762
Carrying value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	4,680	1,062
Loans held-for-sale, net	375	641
Finance receivables and loans, net	135,852	132,034
FHLB/FRB stock	784	719
Deposit liabilities	55,187	42,336
Short-term borrowings	3,297	2,399
Long-term debt	17,570	17,762
Estimated fair value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	4,729	884
Loans held-for-sale, net	375	641
Finance receivables and loans, net	137,244	133,856
FHLB/FRB stock	784	719
Deposit liabilities	55,311	41,909
Short-term borrowings	3,335	2,417
Long-term debt	18,538	18,252
Estimated fair value \| 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
FHLB/FRB stock	0	0
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Estimated fair value \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	4,729	884
Loans held-for-sale, net	0	0
Finance receivables and loans, net	0	0
FHLB/FRB stock	784	719
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	12,789	12,989
Estimated fair value \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0	0
Loans held-for-sale, net	375	641
Finance receivables and loans, net	137,244	133,856
FHLB/FRB stock	0	0
Deposit liabilities	55,311	41,909
Short-term borrowings	3,335	2,417
Long-term debt	$ 5,749	$ 5,263

Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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