Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	$ (6,404)	$ 32,449
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0	424
Net earnings available to common shareholders	$ (6,404)	$ 32,025
Weighted-average outstanding shares of common stock - basic	47,620,774	47,560,749
Dilutive effect of equity incentive plans	0	89,013
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares	0	859,419
Weighted-average outstanding shares of common stock - diluted	47,620,774	48,509,181
Basic	$ (0.13)	$ 0.67
Share options excluded from the computation of diluted earnings per share	0	0
Diluted EPS impact	$ (0.13)	$ 0.66
Share-based Payment Arrangement, Option [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Share options excluded from the computation of diluted earnings per share	40,074
3.25% Convertible Debt Securities [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Share options excluded from the computation of diluted earnings per share	1,460,431
1.75% Convertible Debt Securities [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Share options excluded from the computation of diluted earnings per share	0