Stock-Based Compensation - Assumptions and Activity (Details) - Stock Options. - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Shares
Outstanding at beginning of period (in shares)	18,168
Granted (in shares)	0	0
Exercised (in shares)	0	0
Outstanding at end of period (in shares)	18,168
Exercisable at end of period (in shares)	12,166
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per shares)	$ 13.81
Outstanding at end of period (in dollars per share)	13.81
Exercisable at end of period (in dollars per share)	$ 15.46
Aggregate intrinsic value of all options outstanding	$ 0