Investment Securities - Available-for-sale Securities by Maturities (Details) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		$ 28,343
Debt securities, maturing 1 to 5 years, amortized cost		163,000
Debt securities, maturing 5 to 10 years, amortized cost		200,064
Debt securities, maturing over 10 years, amortized cost		820,387
Amortized Cost		1,211,794	$ 1,300,719
Debt securities, maturing within 1 year, fair value		28,034
Debt securities, maturing 1 to 5 years, fair value		149,131
Debt securities, maturing 5 to 10 years, fair value		168,665
Debt securities, maturing over 10 years, fair value		672,751
Debt securities	[1]	$ 1,018,581	1,131,399
Available-for-sale securities, maturing within 1 year, weighted average yield		2.77%
Available-for-sale securities, maturing 1 to 5 years, weighted average yield		2.27%
Available-for-sale securities, maturing 5 to 10 years, weighted average yield		2.10%
Available-for-sale securities, maturing over 10 years, weighted average yield		2.29%
Available-for-sale securities, total weighted average yield		2.27%
U.S. Treasury and government agencies
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		$ 0
Debt securities, maturing 1 to 5 years, amortized cost		30,703
Debt securities, maturing 5 to 10 years, amortized cost		8,439
Debt securities, maturing over 10 years, amortized cost		6,065
Amortized Cost		45,207	158,473
Debt securities, maturing within 1 year, fair value		0
Debt securities, maturing 1 to 5 years, fair value		28,284
Debt securities, maturing 5 to 10 years, fair value		8,242
Debt securities, maturing over 10 years, fair value		5,940
Debt securities		42,466	152,422
U.S. government sponsored agencies
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		7,929
Debt securities, maturing 1 to 5 years, amortized cost		60,184
Debt securities, maturing 5 to 10 years, amortized cost		32,335
Debt securities, maturing over 10 years, amortized cost		17,700
Amortized Cost		118,148	101,753
Debt securities, maturing within 1 year, fair value		7,858
Debt securities, maturing 1 to 5 years, fair value		54,328
Debt securities, maturing 5 to 10 years, fair value		26,545
Debt securities, maturing over 10 years, fair value		15,201
Debt securities		103,932	88,115
States and political subdivisions
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		18,785
Debt securities, maturing 1 to 5 years, amortized cost		52,478
Debt securities, maturing 5 to 10 years, amortized cost		66,632
Debt securities, maturing over 10 years, amortized cost		125,106
Amortized Cost		263,001	261,612
Debt securities, maturing within 1 year, fair value		18,554
Debt securities, maturing 1 to 5 years, fair value		48,537
Debt securities, maturing 5 to 10 years, fair value		54,148
Debt securities, maturing over 10 years, fair value		99,221
Debt securities		220,460	225,882
Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		1
Debt securities, maturing 1 to 5 years, amortized cost		4,052
Debt securities, maturing 5 to 10 years, amortized cost		61,904
Debt securities, maturing over 10 years, amortized cost		648,544
Amortized Cost		714,501	707,025
Debt securities, maturing within 1 year, fair value		1
Debt securities, maturing 1 to 5 years, fair value		3,845
Debt securities, maturing 5 to 10 years, fair value		54,760
Debt securities, maturing over 10 years, fair value		534,498
Debt securities		593,104	604,653
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		1,628
Debt securities, maturing 1 to 5 years, amortized cost		12,583
Debt securities, maturing 5 to 10 years, amortized cost		27,254
Debt securities, maturing over 10 years, amortized cost		21,119
Amortized Cost		62,584	61,091
Debt securities, maturing within 1 year, fair value		1,621
Debt securities, maturing 1 to 5 years, fair value		11,195
Debt securities, maturing 5 to 10 years, fair value		21,986
Debt securities, maturing over 10 years, fair value		16,038
Debt securities		50,840	50,049
Bank-issued trust preferred securities
Schedule of Available-for-sale Securities
Debt securities, maturing within 1 year, amortized cost		0
Debt securities, maturing 1 to 5 years, amortized cost		3,000
Debt securities, maturing 5 to 10 years, amortized cost		3,500
Debt securities, maturing over 10 years, amortized cost		1,853
Amortized Cost		8,353	10,765
Debt securities, maturing within 1 year, fair value		0
Debt securities, maturing 1 to 5 years, fair value		2,942
Debt securities, maturing 5 to 10 years, fair value		2,984
Debt securities, maturing over 10 years, fair value		1,853
Debt securities		$ 7,779	$ 10,278

[1]     Available-for-sale investment securities and held-to-maturity investment securities are presented net of allowance for credit losses of $0 and $238, respectively, at September 30, 2023, and $0 and $241, respectively, at December 31, 2022.