Investment Securities - Reconciliation of Available-for-Sale and Held-to-Maturity Securities in Continuous Unrealized Loss Position (Detail) $ in Thousands	Jun. 30, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Fair Value
Less Than 12 Months	$ 1,028,822	$ 378,941
12 Months or Longer	70,541	38,045
Total	$ 1,099,363	$ 416,986
Number of Securities | security	423	94
Unrealized Losses
Less Than 12 Months	$ 61,949	$ 3,508
12 Months or Longer	5,671	923
Total	67,620	4,431
Fair Value
Less Than 12 Months	783,431	650,352
12 Months or Longer	13,700	2,376
Total	797,131	652,728
Unrealized Losses
Less Than 12 Months	129,905	11,684
12 Months or Longer	3,043	107
Total	$ 132,948	$ 11,791
Number of Securities | security	577	336
U.S. government agencies
Fair Value
Less Than 12 Months	$ 338,126	$ 76,106
12 Months or Longer	16,698	14,670
Total	$ 354,824	$ 90,776
Number of Securities | security	67	15
Unrealized Losses
Less Than 12 Months	$ 18,373	$ 322
12 Months or Longer	1,550	467
Total	19,923	789
Fair Value
Less Than 12 Months	14,584
12 Months or Longer	0
Total	14,584
Unrealized Losses
Less Than 12 Months	425
12 Months or Longer	0
Total	$ 425
Number of Securities | security	4
Mortgage-backed securities, residential
Fair Value
Less Than 12 Months	$ 326,475	176,990
12 Months or Longer	11,948	14,582
Total	$ 338,423	$ 191,572
Number of Securities | security	126	45
Unrealized Losses
Less Than 12 Months	$ 29,130	$ 1,465
12 Months or Longer	1,241	266
Total	30,371	1,731
Fair Value
Less Than 12 Months	310,639	340,474
12 Months or Longer	8,440	2,376
Total	319,079	342,850
Unrealized Losses
Less Than 12 Months	41,624	5,882
12 Months or Longer	1,532	107
Total	$ 43,156	$ 5,989
Number of Securities | security	175	96
Collateralized mortgage obligations, residential
Fair Value
Less Than 12 Months	$ 142,202	$ 86,749
12 Months or Longer	29,481	5,000
Total	$ 171,683	$ 91,749
Number of Securities | security	101	18
Unrealized Losses
Less Than 12 Months	$ 7,592	$ 1,429
12 Months or Longer	2,049	59
Total	9,641	1,488
Fair Value
Less Than 12 Months	12,067
12 Months or Longer	0
Total	12,067
Unrealized Losses
Less Than 12 Months	1,705
12 Months or Longer	0
Total	$ 1,705
Number of Securities | security	12
Mortgage-backed securities, multifamily
Fair Value
Less Than 12 Months	$ 0	0
12 Months or Longer	1,505	1,741
Total	$ 1,505	$ 1,741
Number of Securities | security	1	1
Unrealized Losses
Less Than 12 Months	$ 0	$ 0
12 Months or Longer	299	75
Total	299	75
Fair Value
Less Than 12 Months	4,662
12 Months or Longer	0
Total	4,662
Unrealized Losses
Less Than 12 Months	477
12 Months or Longer	0
Total	$ 477
Number of Securities | security	4
Collateralized mortgage obligations, multifamily
Fair Value
Less Than 12 Months	$ 48,811	9,083
12 Months or Longer	770	1,072
Total	$ 49,581	$ 10,155
Number of Securities | security	19	4
Unrealized Losses
Less Than 12 Months	$ 3,069	$ 210
12 Months or Longer	90	36
Total	3,159	246
Fair Value
Less Than 12 Months		2,051
12 Months or Longer		0
Total		2,051
Unrealized Losses
Less Than 12 Months		2
12 Months or Longer		0
Total		$ 2
Number of Securities | security		1
Asset-backed securities
Fair Value
Less Than 12 Months	49,524	$ 14,688
12 Months or Longer	7,297	0
Total	$ 56,821	$ 14,688
Number of Securities | security	16	3
Unrealized Losses
Less Than 12 Months	$ 1,442	$ 87
12 Months or Longer	284	0
Total	1,726	87
Obligations of states and political subdivisions
Fair Value
Less Than 12 Months	22,695
12 Months or Longer	0
Total	$ 22,695
Number of Securities | security	50
Unrealized Losses
Less Than 12 Months	$ 903
12 Months or Longer	0
Total	903
Fair Value
Less Than 12 Months	438,702	307,827
12 Months or Longer	5,260	0
Total	443,962	307,827
Unrealized Losses
Less Than 12 Months	85,451	5,800
12 Months or Longer	1,511	0
Total	$ 86,962	$ 5,800
Number of Securities | security	381	239
Corporate bonds
Fair Value
Less Than 12 Months	$ 100,989	$ 15,325
12 Months or Longer	2,842	980
Total	$ 103,831	$ 16,305
Number of Securities | security	43	8
Unrealized Losses
Less Than 12 Months	$ 1,440	$ (5)
12 Months or Longer	158	20
Total	1,598	$ 15
Fair Value
Less Than 12 Months	2,777
12 Months or Longer	0
Total	2,777
Unrealized Losses
Less Than 12 Months	223
12 Months or Longer	0
Total	$ 223
Number of Securities | security	1