Contingent Liabilities and Commitments with Off-Balance Sheet Risk - Summary of Financial Instruments with Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Contract or Notional Amount
Commitments to extend credit	$ 1,018,020	$ 982,739
Unfunded limited partner equity commitment	6,011	7,252
Secured
Contract or Notional Amount
Standby letters of credit and financial guarantees written	13,073	17,736
Unsecured
Contract or Notional Amount
Standby letters of credit and financial guarantees written	$ 663	$ 847