Investment Securities - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	$ 847,845	$ 923,415
AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	520,318	546,563
AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	311,224	317,566
A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	1,020
BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	3,000
BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		3,000
Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	13,303	55,266
U.S. government agencies
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	10,598	11,099
U.S. government agencies | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	10,598	11,099
U.S. government agencies | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
U.S. government agencies | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
U.S. government agencies | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0
U.S. government agencies | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		0
U.S. government agencies | Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Mortgage-backed securities, residential
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	339,427	360,683
Mortgage-backed securities, residential | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	339,427	360,683
Mortgage-backed securities, residential | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Mortgage-backed securities, residential | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Mortgage-backed securities, residential | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0
Mortgage-backed securities, residential | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		0
Mortgage-backed securities, residential | Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Collateralized mortgage obligations, residential
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	12,474	13,026
Collateralized mortgage obligations, residential | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	12,474	13,026
Collateralized mortgage obligations, residential | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Collateralized mortgage obligations, residential | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Collateralized mortgage obligations, residential | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0
Collateralized mortgage obligations, residential | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		0
Collateralized mortgage obligations, residential | Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Mortgage-backed securities, multifamily
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	5,024	5,094
Mortgage-backed securities, multifamily | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	5,024	5,094
Mortgage-backed securities, multifamily | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Mortgage-backed securities, multifamily | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Mortgage-backed securities, multifamily | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0
Mortgage-backed securities, multifamily | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		0
Mortgage-backed securities, multifamily | Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Obligations of states and political subdivisions
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	477,322	530,513
Obligations of states and political subdivisions | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	152,795	156,661
Obligations of states and political subdivisions | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	311,224	317,566
Obligations of states and political subdivisions | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	1,020
Obligations of states and political subdivisions | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0
Obligations of states and political subdivisions | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		0
Obligations of states and political subdivisions | Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	13,303	55,266
Corporate bonds
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	3,000	3,000
Corporate bonds | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Corporate bonds | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Corporate bonds | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	0	0
Corporate bonds | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	3,000
Corporate bonds | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total		3,000
Corporate bonds | Not Rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total	$ 0	$ 0