Derivatives and Hedging Activities (Schedule of Impact of the Derivative Instruments on Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings	$ (136)	$ (82)	$ (4)
Deposits \| Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	(4,772)	(3,886)	(1,257)
Deposits \| Designated as Hedges \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings	0	0	0
Amounts reclassified from OCI into earnings	0
(Losses) gains on hedged items	(19)	0	0
(Losses) gains on interest rate swaps	(1)	0	0
Total (losses) gains on fair value hedging relationships	$ (20)	0	0
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Expense, Deposits
Deposits \| Not Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains on derivatives not designated as hedges			0
Long-term Borrowings \| Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	$ (933)	(855)	(606)
Long-term Borrowings \| Designated as Hedges \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings	9	9	(2)
Amounts reclassified from OCI into earnings	0
(Losses) gains on hedged items	21	(19)	66
(Losses) gains on interest rate swaps	(158)	(80)	(70)
Total (losses) gains on fair value hedging relationships	$ (137)	(99)	(4)
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Expense, Long-Term Debt
Long-term Borrowings \| Not Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains on derivatives not designated as hedges			0
Credit Card Loans \| Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	$ 16,109	14,438	10,632
Credit Card Loans \| Designated as Hedges \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings	(158)	(91)	(2)
Amounts reclassified from OCI into earnings	0
(Losses) gains on hedged items	0	0	0
(Losses) gains on interest rate swaps	0	0	0
Total (losses) gains on fair value hedging relationships	$ 0	0	0
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Credit card loans
Credit Card Loans \| Not Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains on derivatives not designated as hedges			0
Other Income \| Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	$ 763	85	75
Other Income \| Designated as Hedges \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings	0	0	0
Amounts reclassified from OCI into earnings	0
(Losses) gains on hedged items	0	0	0
(Losses) gains on interest rate swaps	0	0	0
Total (losses) gains on fair value hedging relationships	0	0	0
Other Income \| Not Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains on derivatives not designated as hedges			1
Other Expense \| Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	929	803	540
Other Expense \| Designated as Hedges \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings	0	0	0
Amounts reclassified from OCI into earnings	13
(Losses) gains on hedged items	0	0	0
(Losses) gains on interest rate swaps	0	0	0
Total (losses) gains on fair value hedging relationships	$ 0	$ 0	0
Other Expense \| Not Designated as Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains on derivatives not designated as hedges			$ 0

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