Accumulated Other Comprehensive Income - Reclassification Out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Securities (losses) gains, net	$ (38)	$ (1)	$ (84)	$ 12
Interest and fees on loans and leases	1,315	1,014	3,377	3,078
Compensation and benefits	605	627	1,900	1,971
Income (loss) before income taxes	845	895	2,179	2,689
Applicable income tax expense	(192)	(191)	(470)	(582)
Net income	653	704	1,709	2,107
Reclassification out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net income	2	57	107	161
Reclassification out of AOCI | Available-for-sale debt securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Securities (losses) gains, net	0	1	3	(9)
Income (loss) before income taxes	0	1	3	(9)
Applicable income tax expense	0	0	(1)	2
Net income	0	1	2	(7)
Reclassification out of AOCI | Net unrealized gains on cash flow hedge
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest and fees on loans and leases	4	74	140	219
Income (loss) before income taxes	4	74	140	219
Applicable income tax expense	(1)	(16)	(31)	(46)
Net income	3	58	109	173
Reclassification out of AOCI | Net periodic benefit costs
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income (loss) before income taxes	(1)	(3)	(5)	(7)
Applicable income tax expense	0	1	1	2
Net income	(1)	(2)	(4)	(5)
Reclassification out of AOCI | Amortization of net actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Compensation and benefits	(1)	(2)	(3)	(5)
Reclassification out of AOCI | Settlements
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Compensation and benefits	$ 0	$ (1)	$ (2)	$ (2)