Earnings 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]
Anti-dilutive stock options outstanding that were not included in computation of diluted earnings per common share	0
Basic	102,700	100,200	102,700
Dilutive Effect Of Stock Options Restricted Stock And Equity Settled Awards	600	300	400
Diluted	103,300	100,500	103,100
Net income available to common stockholders	$ 895,700	$ 506,600	$ 499,200
Earnings (loss) per share - basic	$ 8.72	$ 5.06	$ 4.86
Diluted	$ 8.67	$ 5.04	$ 4.84