Income Taxes - Summary of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Expected federal tax expense	$ 8,158	$ 7,371	$ 6,280
Nondeductible interest expense	94	78	63
Tax-exempt interest	(1,265)	(1,338)	(1,370)
State income taxes	296	222	405
Other, net	(276)	(313)	(176)
Total income tax expense	$ 7,007	$ 6,020	$ 5,202