Earnings Per Share - Schedule of Dilutive Effect of Stock Options RSUs and PSAs (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net Income	$ 14,611	$ 13,617	$ 29,929	$ 26,034
Weighted-average number of basic shares outstanding during the period	18,805	18,806	18,815	18,738
Dilutive effect of stock options, RSUs, and performance shares	328	403	398	470
Weighted-average number of diluted shares outstanding during the period	19,133	19,209	19,213	19,208
Basic earnings per share	$ 0.78	$ 0.72	$ 1.59	$ 1.39
Diluted earnings per share	$ 0.76	$ 0.71	$ 1.56	$ 1.36