Investment Securities - Reconciliation of Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,212,819	$ 768,689
Gross Unrealized Gains	538	5,781
Gross Unrealized Losses	(41,152)	(4,431)
Allowance for Credit Losses	(1,267)	(83)
Total	1,170,938	769,956
Less Than 12 Months	38,694	3,508
U.S. Treasury and U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	397,100	202,961
Gross Unrealized Gains	131	1,215
Gross Unrealized Losses	(13,516)	(789)
Allowance for Credit Losses	0	0
Total	383,715	203,387
Less Than 12 Months	12,391	322
Mortgage-backed securities, residential
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	377,454	238,456
Gross Unrealized Gains	59	1,250
Gross Unrealized Losses	(16,817)	(1,731)
Allowance for Credit Losses	0	0
Total	360,696	237,975
Less Than 12 Months	15,974	1,465
Collateralized mortgage obligations, residential
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	196,369	191,086
Gross Unrealized Gains	80	1,693
Gross Unrealized Losses	(6,659)	(1,488)
Allowance for Credit Losses	0	0
Total	189,790	191,291
Less Than 12 Months	6,557	1,429
Mortgage-backed securities, multifamily
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,809	1,816
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(206)	(75)
Allowance for Credit Losses	0	0
Total	1,603	1,741
Less Than 12 Months	0	0
Collateralized mortgage obligations, multifamily
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	56,101	32,254
Gross Unrealized Gains	31	511
Gross Unrealized Losses	(1,901)	(246)
Allowance for Credit Losses	0	0
Total	54,231	32,519
Less Than 12 Months	1,832	210
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	63,685	52,518
Gross Unrealized Gains	9	153
Gross Unrealized Losses	(738)	(87)
Allowance for Credit Losses	0	0
Total	62,956	52,584
Less Than 12 Months	738	87
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	24,069
Gross Unrealized Gains	1
Gross Unrealized Losses	(590)
Allowance for Credit Losses	(2)
Total	23,478
Less Than 12 Months	590
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	96,232	49,598
Gross Unrealized Gains	227	959
Gross Unrealized Losses	(725)	(15)
Allowance for Credit Losses	(1,265)	(83)
Total	94,469	50,459
Less Than 12 Months	$ 612	$ (5)

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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