Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income (loss) to shareholders	$ 35,614	$ 20,307	$ (1,201)	$ 43,035
Weighted average common shares outstanding:
Basic (in shares)	30,529,241	30,246,420	30,502,774	30,153,426
Common share equivalents (in shares)	253,368	442,654	0	427,779
Diluted (in shares)	30,782,609	30,689,074	30,502,774	30,581,205
Earnings (loss) per share:
Basic (in dollars per share)	$ 1.17	$ 0.67	$ (0.04)	$ 1.43
Common share equivalents (in dollars per share)	(0.01)	(0.01)	0	(0.02)
Diluted (in dollars per share)	$ 1.16	$ 0.66	$ (0.04)	$ 1.41