Fair Value of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other investments:
Mutual fund - CRA qualified	$ 2,534	$ 2,488
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
U.S. Government sponsored agency securities	6,940	6,906
Mortgage-backed securities - residential	13,700	14,129
Collateralized mortgage obligations	33,476	34,301
Other investments:
Mutual fund - CRA qualified	2,534	2,488
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Other investments:
Mutual fund - CRA qualified	2,534	2,488
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
U.S. Government sponsored agency securities	6,940	6,906
Mortgage-backed securities - residential	13,700	14,129
Collateralized mortgage obligations	$ 33,476	$ 34,301