Components of Other Comprehensive Income (Loss) - Schedule of Reclassification from AOCI (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and fees on loans and leases	$ 617			$ 482			$ 1,553	$ 1,485
Income tax expense	78			63			183	222
Other expense	44			52			156	171
Amounts reclassified from AOCI	(268)	$ (177)	$ (198)	(235)	$ (311)	$ (236)	(642)	(781)
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	7			1			13	2
Reclassification out of Accumulated Other Comprehensive Income | Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and fees on loans and leases	5			(2)			9	(6)
Income tax expense	(1)			1			(2)	2
Amounts reclassified from AOCI	4			(1)			7	(4)
Reclassification out of Accumulated Other Comprehensive Income | Pension and Post-retirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax expense	(1)			(1)			(2)	(2)
Other expense	4			3			8	8
Amounts reclassified from AOCI	$ 3			$ 2			$ 6	$ 6