Investment Securities - Summary of Contractual Maturities of Investment Securities Classified as Available for Sale and Held to Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Available for Sale, Amortized Cost
Due in one year or less	$ 42,276
Due after one year through five years	250,381
Due after five years through ten years	155,291
Due after ten years	61,862
Total	509,810
Total	1,122,901	$ 1,158,534
Available for Sale, Fair Value
Due in one year or less	41,645
Due after one year through five years	235,641
Due after five years through ten years	139,130
Due after ten years	56,351
Total	472,767
Total	1,029,127	1,054,312
Held to Maturity, Amortized Cost
Due in one year or less	54,927
Due after one year through five years	33,746
Due after five years through ten years	77,738
Due after ten years	363,846
Total	530,257
Amortized Cost	902,655	923,415
Held to Maturity, Fair Value
Due in one year or less	54,712
Due after one year through five years	32,297
Due after five years through ten years	68,421
Due after ten years	290,602
Total	446,032
Total	762,720	$ 760,455
Mortgage-backed and asset-backed securities
Available for Sale, Amortized Cost
Mortgage-backed and asset-backed securities	613,091
Available for Sale, Fair Value
Mortgage-backed and asset-backed securities	556,360
Held to Maturity, Amortized Cost
Mortgage-backed and asset-backed securities	372,398
Held to Maturity, Fair Value
Mortgage-backed and asset-backed securities	$ 316,688