Deposits and Borrowings - Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total long-term debt	$ 48,235	$ 47,832
Total short-term borrowings and long-term debt	48,777	48,715
Senior and subordinated notes	30,398	30,826
Euro
Debt Instrument [Line Items]
Senior and subordinated notes	$ 1,200	1,200
Securitized debt obligations
Debt Instrument [Line Items]
Weighted average interest rate	2.80%
Carrying value	$ 17,813	16,973
Total senior and subordinated notes
Debt Instrument [Line Items]
Carrying value	$ 30,398	30,826
Senior notes \| Total unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	3.72%
Carrying value	$ 26,676	25,731
Senior notes \| Fixed unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	3.63%
Carrying value	$ 25,429	24,134
Senior notes \| Floating unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	5.69%
Carrying value	$ 1,247	1,597
Subordinated notes \| Fixed unsecured subordinated debt
Debt Instrument [Line Items]
Weighted average interest rate	3.57%
Carrying value	$ 3,722	5,095
Finance lease liabilities
Debt Instrument [Line Items]
Weighted average interest rate	5.76%
Carrying value	$ 24	33
Total other long-term borrowings
Debt Instrument [Line Items]
Carrying value	$ 24	$ 33
Minimum \| Securitized debt obligations
Debt Instrument [Line Items]
Stated interest rates	0.32%
Minimum \| Senior notes \| Fixed unsecured senior debt
Debt Instrument [Line Items]
Stated interest rates	0.80%
Minimum \| Senior notes \| Floating unsecured senior debt
Debt Instrument [Line Items]
Stated interest rates	5.51%
Minimum \| Subordinated notes \| Fixed unsecured subordinated debt
Debt Instrument [Line Items]
Stated interest rates	2.36%
Minimum \| Finance lease liabilities
Debt Instrument [Line Items]
Stated interest rates	0.35%
Maximum \| Securitized debt obligations
Debt Instrument [Line Items]
Stated interest rates	5.38%
Maximum \| Senior notes \| Fixed unsecured senior debt
Debt Instrument [Line Items]
Stated interest rates	5.82%
Maximum \| Senior notes \| Floating unsecured senior debt
Debt Instrument [Line Items]
Stated interest rates	6.17%
Maximum \| Subordinated notes \| Fixed unsecured subordinated debt
Debt Instrument [Line Items]
Stated interest rates	4.20%
Maximum \| Finance lease liabilities
Debt Instrument [Line Items]
Stated interest rates	9.91%

Amount of short-term and long-term debt and lease obligation.

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