Investment Securities - Amortized Cost of Debt Securities Held-to-Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	$ 186,748	$ 199,759
AAA/AA/A
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	186,748	199,759
BBB/BB/B
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	0	0
Obligations of U.S. government agencies | AAA/AA/A
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	180,290	192,068
Obligations of U.S. government agencies | BBB/BB/B
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	0	0
Obligations of states and political subdivisions | AAA/AA/A
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	6,458	7,691
Obligations of states and political subdivisions | BBB/BB/B
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Securities held to maturity	$ 0	$ 0