Investment Securities - Reconciliation of Available-for-Sale Securities (Detail) $ in Thousands	Mar. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,122,901	$ 1,158,534
Gross Unrealized Gains	101	106
Gross Unrealized Losses	(93,715)	(104,018)
Allowance for Credit Losses	(160)	(310)	$ (1,267)	$ (83)
Total	1,029,127	1,054,312
Less Than 12 Months	70,038	129,018
Less Than 12 Months	1,026	7,192
12 Months or Longer	680,671	617,633
12 Months or Longer	$ 138,889	$ 155,731
Number of Securities | security	568	581
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 750,709	$ 746,651
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	139,915	162,923
U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	372,114	383,958
Gross Unrealized Gains	95	100
Gross Unrealized Losses	(23,790)	(28,419)
Allowance for Credit Losses	0	0
Total	348,419	355,639
Less Than 12 Months	0	6,671
Less Than 12 Months	0	336
12 Months or Longer	9,115	2,412
12 Months or Longer	$ 622	$ 389
Number of Securities | security	3	3
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 9,115	$ 9,083
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	622	725
Mortgage-backed securities, residential
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	344,792	351,355
Gross Unrealized Gains	6	6
Gross Unrealized Losses	(36,615)	(40,748)
Allowance for Credit Losses	0	0
Total	308,183	310,613
Less Than 12 Months	20,853	32,549
Less Than 12 Months	849	2,275
12 Months or Longer	274,937	264,035
12 Months or Longer	$ 51,994	$ 55,853
Number of Securities | security	183	182
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 295,790	$ 296,584
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	52,843	58,128
Collateralized mortgage obligations, residential
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	165,787	170,502
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(14,069)	(16,444)
Allowance for Credit Losses	0	0
Total	151,718	154,058
Less Than 12 Months	0	4,668
Less Than 12 Months	0	516
12 Months or Longer	10,488	5,787
12 Months or Longer	$ 2,325	$ 2,054
Number of Securities | security	11	12
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 10,488	$ 10,455
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	2,325	2,570
Mortgage-backed securities, multifamily
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	994	1,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(206)	(215)
Allowance for Credit Losses	0	0
Total	788	785
Less Than 12 Months	0
Less Than 12 Months	0
12 Months or Longer	4,406
12 Months or Longer	$ 665
Number of Securities | security	4
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 4,406
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	665
Collateralized mortgage obligations, multifamily
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,692	51,108
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(4,270)	(4,775)
Allowance for Credit Losses	0	0
Total	46,422	46,333
Less Than 12 Months		2,671
Less Than 12 Months		376
12 Months or Longer		1,676
12 Months or Longer		$ 371
Number of Securities | security		4
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value		$ 4,347
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss		747
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,826	54,105
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,577)	(1,710)
Allowance for Credit Losses	0	0
Total	49,249	52,395
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	21,993	22,112
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(701)	(989)
Allowance for Credit Losses	(2)	(1)
Total	21,290	21,122
Less Than 12 Months	49,185	82,459
Less Than 12 Months	177	3,689
12 Months or Longer	379,143	341,076
12 Months or Longer	$ 82,865	$ 96,711
Number of Securities | security	366	379
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 428,328	$ 423,535
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	83,042	100,400
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	115,703	124,394
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(12,487)	(10,718)
Allowance for Credit Losses	(158)	(309)
Total	103,058	113,367
Less Than 12 Months	0
Less Than 12 Months	0
12 Months or Longer	2,582
12 Months or Longer	$ 418
Number of Securities | security	1
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value	$ 2,582
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss	$ 418
Debt securities
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months		0
Less Than 12 Months		0
12 Months or Longer		2,647
12 Months or Longer		$ 353
Number of Securities | security		1
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value		$ 2,647
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Accumulated Loss		$ 353