Net Income Per Share - Calculation of Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net income	$ 598,626	$ 306,276	$ 454,433
Basic:
Weighted average shares (in shares)	110,482	112,729	115,656
Diluted:
Weighted average shares (in shares)	110,482	112,729	115,656
Dilutive effect of potential common shares (in shares)	1,236	589	755
Diluted weighted average shares (in shares)	111,718	113,318	116,411
Net income per share:
Basic (usd per share)	$ 5.42	$ 2.72	$ 3.93
Diluted (usd per share)	$ 5.36	$ 2.70	$ 3.90