Fair Value Measurements - Fair Value Measurement on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	$ 961,092	$ 952,312
U.S. Treasury and U.S. Government-sponsored agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	87,062	105,223
Municipal securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	179,608	133,014
Residential
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	322,684	339,608
Commercial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	325,756	327,095
Corporate obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	23,832	24,194
Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	22,150	23,178
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		952,312
Equity security	96	148
Recurring | U.S. Treasury and U.S. Government-sponsored agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	87,062	105,223
Recurring | Municipal securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	179,608	133,014
Recurring | Residential
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	322,684	339,608
Recurring | Commercial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	325,756	327,095
Recurring | Corporate obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	23,832	24,194
Recurring | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	22,150	23,178
Recurring | Interest rate swap
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets - interest rate swaps	28,075	8,318
Derivative liabilities - interest rate swaps	28,075	8,318
Recurring | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		0
Equity security	96	148
Recurring | Level 1 | U.S. Treasury and U.S. Government-sponsored agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 1 | Municipal securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	850	0
Recurring | Level 1 | Residential
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 1 | Commercial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 1 | Corporate obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 1 | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 1 | Interest rate swap
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets - interest rate swaps	0	0
Derivative liabilities - interest rate swaps	0	0
Recurring | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		952,312
Equity security	0	0
Recurring | Level 2 | U.S. Treasury and U.S. Government-sponsored agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	87,062	105,223
Recurring | Level 2 | Municipal securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	178,758	133,014
Recurring | Level 2 | Residential
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		339,608
Recurring | Level 2 | Commercial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		327,095
Recurring | Level 2 | Corporate obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		24,194
Recurring | Level 2 | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale		23,178
Recurring | Level 2 | Interest rate swap
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets - interest rate swaps	28,075	8,318
Derivative liabilities - interest rate swaps	28,075	8,318
Recurring | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Equity security	0	0
Recurring | Level 3 | U.S. Treasury and U.S. Government-sponsored agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 3 | Municipal securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 3 | Residential
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 3 | Commercial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 3 | Corporate obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 3 | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total investment securities available for sale	0	0
Recurring | Level 3 | Interest rate swap
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative assets - interest rate swaps	0	0
Derivative liabilities - interest rate swaps	$ 0	$ 0