Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Deferred Compensation Trust	Deferred Compensation Liability
Beginning Balance at Dec. 31, 2018	$ 1,808,562	$ 206	$ 1,820,223	$ 7,031,333	$ (7,043,200)	$ (16,937)	$ 16,937
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	878,539			878,539
Deferred compensation activity, net						25	(25)
Purchase of common stock for treasury	(698,417)				(698,417)
Equity-based compensation	78,532		78,532
Proceeds from stock options exercised	274,028		274,028
Treasury stock issued upon option exercise and restricted share vesting			(117,376)		117,376
Ending Balance at Dec. 31, 2019	2,341,244	206	2,055,407	7,909,872	(7,624,241)	(16,912)	16,912
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	901,248			901,248
Deferred compensation activity, net						202	(202)
Purchase of common stock for treasury	(371,078)				(371,078)
Equity-based compensation	50,794		50,794
Proceeds from stock options exercised	180,866		180,866
Treasury stock issued upon option exercise and restricted share vesting			(72,641)		72,641
Ending Balance at Dec. 31, 2020	3,103,074	206	2,214,426	8,811,120	(7,922,678)	(16,710)	16,710
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,236,719			1,236,719
Purchase of common stock for treasury	(1,538,019)				(1,538,019)
Equity-based compensation	58,234		58,234
Proceeds from stock options exercised	142,370		142,370
Treasury stock issued upon option exercise and restricted share vesting			(36,839)		36,839
Ending Balance at Dec. 31, 2021	$ 3,002,378	$ 206	$ 2,378,191	$ 10,047,839	$ (9,423,858)	$ (16,710)	$ 16,710