Federal, State and Local Taxes - Components of Net Deferred Tax Asset (Liability) (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets:
Allowance for credit losses on loans and leases	$ 55	$ 53
Acquisition accounting and fair value adjustments on securities (including OTTI)	21
Compensation and related benefit obligations	17	21
Net operating loss carryforwards	1	6
Other	15	18
Gross deferred tax assets	109	98
Deferred tax asset after valuation allowance	109	98
Deferred Tax Liabilities:
Amortizable intangibles	(3)	(3)
Acquisition accounting and fair value adjustments on securities (including OTTI)		(13)
Premises and equipment	(5)	(6)
Prepaid pension cost	(35)	(25)
Fair value adjustments on loans	(81)	(92)
Leases	(360)	(370)
Other	(9)	(9)
Gross deferred tax liabilities	(493)	(518)
Net deferred tax liability	$ (384)	$ (420)