Securities - Contractual Maturities of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Amortized Cost
Due in one year or less	$ 22,976
Due after one year through five years	156,965
Due after five years through ten years	22,503
Due after ten years	0
Available-for-Sale Debt Securities With Fixed Maturities	202,444
Amortized Cost	1,057,581	$ 1,051,313
Fair Value
Due in one year or less	22,705
Due after one year through five years	145,090
Due after five years through ten years	22,389
Due after ten years	0
Available-for-Sale Debt Securities With Fixed Maturities	190,184
Total Available-for-Sale Debt Securities, Fair Value	969,793	969,308
Collateralized mortgage obligations of U.S. government corporations and agencies
Amortized Cost
Available-for-Sale Debt Securities With Fixed Maturities	517,555
Amortized Cost	517,555	507,942
Fair Value
Available-for-Sale Debt Securities With Fixed Maturities	467,198
Total Available-for-Sale Debt Securities, Fair Value	467,198	460,939
Residential mortgage-backed securities of U.S. government corporations and agencies
Amortized Cost
Available-for-Sale Debt Securities With Fixed Maturities	43,714
Amortized Cost	43,714	44,707
Fair Value
Available-for-Sale Debt Securities With Fixed Maturities	36,662
Total Available-for-Sale Debt Securities, Fair Value	36,662	38,177
Commercial mortgage-backed securities of U.S. government corporations and agencies
Amortized Cost
Available-for-Sale Debt Securities With Fixed Maturities	293,868
Amortized Cost	293,868	290,775
Fair Value
Available-for-Sale Debt Securities With Fixed Maturities	275,749
Total Available-for-Sale Debt Securities, Fair Value	$ 275,749	$ 273,425