Summary of Significant Accounting Policies - Reconciliation between Basic and Diluted Weighted Average Shares Outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Net income	$ 587,104	$ 480,483	$ 398,514
Net income attributable to unvested awarded performance stock	(12,942)	(15,197)	(12,873)
Net income attributable to common shares	$ 574,162	$ 465,286	$ 385,641
Weighted average number of common shares outstanding – basic	282,246	283,294	281,566
Less unvested awarded performance stock included in weighted average number of common shares outstanding – basic	(6,222)	(8,960)	(9,095)
Weighted average number of common shares outstanding for basic earnings per common share	276,024	274,334	272,471
Dilutive effect of stock options	1,390	1,533	2,145
Weighted average number of shares outstanding – diluted	277,414	275,867	274,616
Net income per share:
Basic (in dollars per share)	$ 2.08	$ 1.70	$ 1.42
Diluted (in dollars per share)	$ 2.07	$ 1.69	$ 1.40