Income Taxes - Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Losses on loans and other assets	$ 671	$ 686	$ 641
Operating lease liabilities	170	182	183
Postretirement and other employee benefits	63	47	0
Incentive and other compensation plans	36	30	34
Unrealized losses	52	64	115
Interest on loans	28	42	54
Losses on cash flow hedges	34	52	87
Stock-based compensation	49	54	51
Other	139	153	81
Gross deferred tax assets	1,242	1,310	1,246
Deferred tax liabilities:
Retirement benefits	(304)	(198)	(88)
Leases	(150)	(171)	(204)
Right-of-use assets	(147)	(165)	(163)
Depreciation and amortization	(56)	(157)	(155)
Capitalized servicing rights	(36)	(38)	(51)
Postretirement and other employee benefits	0	0	(29)
Other	(68)	(59)	(69)
Gross deferred tax liabilities	(761)	(788)	(759)
Net deferred tax asset	$ 481	$ 522	$ 487