Securities - Reconciliation of Held-to-Maturity Securities (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 825,137,000	$ 90,766,000
Gross Unrealized Gains	2,046,000	3,114,000
Gross Unrealized Losses	(11,791,000)	(12,000)
Allowance for Credit Losses	(181,000)	0
Fair Value	815,211,000	93,868,000
U.S. government agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	18,672,000	25,565,000
Gross Unrealized Gains	293,000	779,000
Gross Unrealized Losses	0	0
Allowance for Credit Losses	0	0
Fair Value	18,965,000	26,344,000
Mortgage-backed securities, residential
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	370,247,000	39,276,000
Gross Unrealized Gains	718,000	1,469,000
Gross Unrealized Losses	(5,989,000)	(12,000)
Allowance for Credit Losses	0	0
Fair Value	364,976,000	40,733,000
Collateralized mortgage obligations, residential
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	13,921,000	14,590,000
Gross Unrealized Gains	168,000	532,000
Gross Unrealized Losses	0	0
Allowance for Credit Losses	0	0
Fair Value	14,089,000	15,122,000
Mortgage-backed securities, multifamily
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	2,710,000	705,000
Gross Unrealized Gains	26,000	54,000
Gross Unrealized Losses	(2,000)	0
Allowance for Credit Losses	0	0
Fair Value	2,734,000	759,000
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	416,587,000	10,630,000
Gross Unrealized Gains	810,000	280,000
Gross Unrealized Losses	(5,800,000)	0
Allowance for Credit Losses	(21,000)	0
Fair Value	411,576,000	$ 10,910,000
Debt securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,000,000
Gross Unrealized Gains	31,000
Gross Unrealized Losses	0
Allowance for Credit Losses	(160,000)
Fair Value	$ 2,871,000