(Loss) Earnings Per Common Share - Computation of basic and diluted (loss) earnings per common share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Basic (Loss) Earnings Per Share:
Net (loss) income available to common shareholders	$ (22,482)	$ 11,482
Less: (loss) income allocated to participating securities	(39)	9
Net (loss) income allocated to common shareholders	$ (22,443)	$ 11,473
Weighted average common shares outstanding including participating securities	31,721	20,030
Less: Participating securities	55	16
Average common shares	31,666	20,014
Basic (loss) earnings per common share	$ (0.71)	$ 0.57
Diluted (Loss) Earnings Per Share:
Net (loss) income allocated to common shareholders	$ (22,443)	$ 11,473
Weighted average common shares outstanding for basic (loss) earnings per common share	31,666	20,014
Add: Dilutive effects of stock options		81
Average shares and dilutive potential common shares	31,666	20,095
Diluted (loss) earnings per common share	$ (0.71)	$ 0.57