Earnings Per Share - Two-class method (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share
Net Income	$ 15,215	$ 5,363
Dividends and undistributed earnings allocated to participating securities	254	82
Net income available to common shareholders	$ 14,961	$ 5,281
Weighted-average common shares outstanding	17,145	17,070
Dilutive effect of stock-based awards	320	335
Weighted-average common shares outstanding for diluted earnings per share	17,465	17,405
Earnings per common share:
Basic earnings per common share	$ 0.87	$ 0.31
Diluted earnings per common share	$ 0.86	$ 0.30