Earnings Per Share - Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income	$ 288,957	$ 75,387	$ 222,878
Income allocated to participating securities	(1,125)	(423)	(1,352)
Net income available to common shareholders	$ 287,832	$ 74,964	$ 221,526
Denominator:
Weighted average common shares outstanding - basic (in shares)	55,379	55,175	55,358
Basic earnings per share (in dollars per share)	$ 5.20	$ 1.36	$ 4.00
Numerator:
Net income	$ 288,957	$ 75,387	$ 222,878
Income allocated to participating securities	(1,125)	(423)	(1,346)
Net income available to common shareholders	$ 287,832	$ 74,964	$ 221,532
Denominator:
Weighted average common shares outstanding - basic (in shares)	55,379	55,175	55,358
Diluted effect of stock options and PVRSUs (in shares)	504	354	310
Weighted average commons shares outstanding - diluted (in shares)	55,883	55,529	55,668
Diluted earnings per share (in dollars per share)	$ 5.15	$ 1.35	$ 3.98