Investment Securities - Schedule of Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Amortized cost
Due in one year or less	$ 34,965	$ 4,277
Due in one to five years	138,189	161,556
Due in five to ten years	58,876	61,290
Due in over ten years	229,559	234,720
Amortized cost, sub-total	461,589	461,843
Total debt securities	1,678,270	1,705,574
Fair value
Due in one year or less	34,270	4,225
Due in one to five years	130,585	152,181
Due in five to ten years	56,982	57,859
Due in over ten years	206,057	205,084
Fair value, sub-total	427,894	419,349
Total debt securities	1,471,005	1,471,186
Mortgage-backed securities - residential
Amortized cost
Mortgage-backed securities	1,197,702	1,224,522
Total debt securities	1,197,702	1,224,522
Fair value
Mortgage-backed securities	1,025,388	1,034,193
Total debt securities	1,025,388	1,034,193
Mortgage-backed securities - commercial
Amortized cost
Mortgage-backed securities	18,979	19,209
Total debt securities	18,979	19,209
Fair value
Mortgage-backed securities	17,723	17,644
Total debt securities	$ 17,723	$ 17,644