Investment Securities - Summary of Contractual Maturities of Investment Securities Classified as Available for Sale and Held to Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Available for Sale, Amortized Cost
Due in one year or less	$ 24,606
Due after one year through five years	254,918
Due after five years through ten years	190,823
Due after ten years	70,425
Total	540,772
Total	1,209,588	$ 768,689
Available for Sale, Fair Value
Due in one year or less	24,384
Due after one year through five years	244,056
Due after five years through ten years	181,632
Due after ten years	65,711
Total	515,783
Total	1,139,414	769,956
Held to Maturity, Amortized Cost
Due in one year or less	72,185
Due after one year through five years	33,004
Due after five years through ten years	67,896
Due after ten years	386,680
Total	559,765
Amortized Cost	941,748	825,137
Held to Maturity, Fair Value
Due in one year or less	71,921
Due after one year through five years	32,092
Due after five years through ten years	60,215
Due after ten years	307,767
Total	471,995
Total	808,663	$ 815,211
Mortgage-backed and asset-backed securities
Available for Sale, Amortized Cost
Mortgage-backed and asset-backed securities	668,816
Available for Sale, Fair Value
Mortgage-backed and asset-backed securities	623,631
Held to Maturity, Amortized Cost
Mortgage-backed and asset-backed securities	381,983
Held to Maturity, Fair Value
Mortgage-backed and asset-backed securities	$ 336,668