Deposits and Borrowings - Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total long-term debt	$ 40,764	$ 42,266
Total short-term borrowings and long-term debt	45,358	43,086
EUR denominated unsecured notes	26,976	27,219
Euro
Debt Instrument [Line Items]
EUR denominated unsecured notes	$ 1,300	1,400
Securitized debt obligations
Debt Instrument [Line Items]
Weighted average interest rate	1.59%
Carrying value	$ 13,740	14,994
Total senior and subordinated notes
Debt Instrument [Line Items]
Carrying value	$ 26,976	27,219
Senior notes \| Total unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	2.81%
Carrying value	$ 21,667	21,684
Senior notes \| Fixed unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	2.94%
Carrying value	$ 20,182	19,975
Senior notes \| Floating unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	1.01%
Carrying value	$ 1,485	1,709
Subordinated notes \| Fixed unsecured subordinated debt
Debt Instrument [Line Items]
Weighted average interest rate	3.52%
Carrying value	$ 5,309	5,535
Finance lease liabilities
Debt Instrument [Line Items]
Weighted average interest rate	3.45%
Carrying value	$ 48	53
Total other long-term borrowings
Debt Instrument [Line Items]
Carrying value	$ 48	$ 53
Minimum \| Securitized debt obligations
Debt Instrument [Line Items]
Stated interest rates	0.13%
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	0.96%
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	0.30%
Maximum \| Securitized debt obligations
Debt Instrument [Line Items]
Stated interest rates	2.80%
Maximum \| Senior notes \| Fixed unsecured senior debt
Debt Instrument [Line Items]
Stated interest rates	4.25%
Maximum \| Senior notes \| Floating unsecured senior debt
Debt Instrument [Line Items]
Stated interest rates	1.16%
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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