Income Taxes - Summary of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Expected federal tax expense	$ 5,411	$ 5,927	$ 9,126
Tax impact from enacted change in tax rate	0	0	2,747
Nondeductible interest expense	67	69	85
Tax-exempt interest	(478)	(504)	(949)
State income taxes	149	337	296
Other, net	(288)	(183)	(479)
Total income tax expense	4,861	5,646	10,826
Downward adjustment of net deferred tax assets	$ 0	$ 0	$ 2,747