Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income (loss) to shareholders	$ 26,283	$ (25,167)	$ 25,082	$ 17,868
Weighted average common shares outstanding:
Basic (in shares)	30,582,540	30,382,105	30,529,557	30,230,490
Common share equivalents (in shares)	364,303	0	309,038	428,899
Diluted (in shares)	30,946,843	30,382,105	30,838,595	30,659,389
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.86	$ (0.83)	$ 0.82	$ 0.59
Common share equivalents (in dollars per share)	(0.01)	0	(0.01)	(0.01)
Diluted (in dollars per share)	$ 0.85	$ (0.83)	$ 0.81	$ 0.58