Earnings Per Share - Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 110,690	$ 36,760
Less: distributed earnings allocated to participating securities	(158)	(135)
Less: undistributed earnings allocated to participating securities	(463)	(96)
Net income attributable to common stockholders (numerator for basic earnings per share)	110,069	36,529
Add back: undistributed earnings allocated to participating securities	463	96
Less: undistributed earnings reallocated to participating securities	(447)	(93)
Numerator for diluted earnings per share under two class method	$ 110,085	$ 36,532
Weighted-average common shares outstanding (in shares)	69,790,927	67,490,537
Denominator for diluted earnings per share under two class method (in shares)	72,788,177	70,125,723
Basic Earnings Per Common Share (in dollars per share)	$ 1.58	$ 0.54
Diluted Earnings Per Common Share (in dollars per share)	$ 1.51	$ 0.52
Stock option grants expense
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted-average common shares outstanding, dilutive effect of stock options and performance share units (in shares)	2,367,394	2,011,629
Performance Shares
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted-average common shares outstanding, dilutive effect of stock options and performance share units (in shares)	629,856	623,557