Derivative Financial Instruments - Amounts Related to Fair Value Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Income recognized from securities with terminated hedges	$ 12	$ 17	$ 22		$ 25
Fair Value Hedges | Interest Rate Contracts | Net interest income
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Net income (expense) recognized	59	74	113		153
Fair Value Hedges | Interest Rate Contracts | Investment securities | Net interest income
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Amounts related to interest settlements	87	9	163		4
Recognized on derivatives	42	60	(53)		474
Recognized on hedged items	(31)	(42)	75		(444)
Net income (expense) recognized	98	27	185	[1]	34	[1]
Fair Value Hedges | Interest Rate Contracts | Loans and leases | Net interest income
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Recognized on hedged items	0	0	(1)		(1)
Net income (expense) recognized	0	0	(1)		(1)
Fair Value Hedges | Interest Rate Contracts | Long-term debt | Net interest income
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Amounts related to interest settlements	(47)	3	(93)		19
Recognized on derivatives	(291)	(38)	(135)		(467)
Recognized on hedged items	299	82	157		568
Net income (expense) recognized	$ (39)	$ 47	$ (71)		$ 120

[1] Includes $12 million and $22 million of income recognized for the three and six months ended June 30, 2023, respectively, and $17 million and $25 million for the three and six months ended June 30, 2022, respectively, from securities with terminated hedges that were reclassified to HTM. The income recognized was offset by the amortization of the fair value mark.