Fair Value - Financial Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	$ 442,636	$ 489,596
U.S. Treasury
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	382,369	418,474
Agency mortgage-backed securities
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	60,267	71,122
Recurring basis
Financial Assets and Liabilities Measured on a Recurring Basis
I/O strip receivables	117	152
Recurring basis | U.S. Treasury
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	382,369	418,474
Recurring basis | Agency mortgage-backed securities
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	60,267	71,122
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	382,369	418,474
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial Assets and Liabilities Measured on a Recurring Basis
I/O strip receivables	117	152
Recurring basis | Significant Other Observable Inputs (Level 2) | Agency mortgage-backed securities
Financial Assets and Liabilities Measured on a Recurring Basis
Securities available-for-sale	$ 60,267	$ 71,122