Summary of Stock Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) Years $ / shares shares	Dec. 31, 2017 USD ($) Years $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options outstanding | shares	124,653	174,510
Options granted | shares	0
Options exercised | shares	(49,857)
Options outstanding weighted average exercise price | $ / shares	$ 30.31	$ 28.70
Options outstanding weighted average exercise price - Granted | $ / shares	0
Options outstanding weighted average exercise price - Exercised | $ / shares	$ 24.69
Options outstanding weighted average remaining term | Years	6.1	6.0
Options outstanding weighted average grant date fair value | $	$ 1,406	$ 1,901
Options granted weighted average grant date fair value | $	0
Options exercised weighted average grant date fair value | $	$ (495)
Options exercisable at September 30, 2018 | shares	108,188
Options exerciseable weighted average exercise price | $ / shares	$ 30.34
Options exerciseable weighted average remaining term | Years	6.0
Options vested weighted average grant date fair value | $	$ 454
Options vested during nine months ended September 30, 2018 | shares	28,129
Options exercisable weighted average grant date fair value | $	$ 1,182