Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning shareholders' equity (shares) at Dec. 31, 2020		266,464
Beginning shareholders' equity at Dec. 31, 2020	$ 6,569,989	$ 2,665	$ 3,261,412	$ (145)	$ 3,306,057
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (shares)		1
Stock option exercises	11		11
Share issuances (shares)		518
Share issuances	4,181	$ 5	4,176
Dividends declared	(110,305)				(110,305)
Share repurchases (shares)		(12,017)
Share repurchases	(614,303)	$ (120)			(614,183)
Cash paid for shares withheld for taxes	(10,642)				(10,642)
Share-based compensation	19,691		19,691
Net income	1,283,055				1,283,055
Other comprehensive income	75			75
Ending shareholders' equity (shares) at Sep. 30, 2021		254,966
Ending shareholders' equity at Sep. 30, 2021	7,141,752	$ 2,550	3,285,290	(70)	3,853,982
Beginning shareholders' equity (shares) at Jun. 30, 2021		260,067
Beginning shareholders' equity at Jun. 30, 2021	6,958,468	$ 2,600	3,280,779	(95)	3,675,184
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (shares)		1
Dividends declared	(36,166)				(36,166)
Share repurchases (shares)		(5,102)
Share repurchases	(260,600)	$ (50)			(260,550)
Cash paid for shares withheld for taxes	(35)				(35)
Share-based compensation	4,511		4,511
Net income	475,549				475,549
Other comprehensive income	25			25
Ending shareholders' equity (shares) at Sep. 30, 2021		254,966
Ending shareholders' equity at Sep. 30, 2021	7,141,752	$ 2,550	3,285,290	(70)	3,853,982
Beginning shareholders' equity (shares) at Dec. 31, 2021		249,326
Beginning shareholders' equity at Dec. 31, 2021	7,489,515	$ 2,493	3,290,791	(45)	4,196,276
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share issuances (shares)		675
Share issuances	6,030	$ 6	6,024
Dividends declared	(106,650)				(106,650)
Share repurchases (shares)		(21,769)
Share repurchases	(974,673)	$ (217)			(974,456)
Cash paid for shares withheld for taxes	(14,325)				(14,325)
Share-based compensation	28,975		28,975
Net income	1,735,086				1,735,086
Other comprehensive income	45			45
Ending shareholders' equity (shares) at Sep. 30, 2022		228,232
Ending shareholders' equity at Sep. 30, 2022	8,164,003	$ 2,282	3,325,790	0	4,835,931
Beginning shareholders' equity (shares) at Jun. 30, 2022		232,570
Beginning shareholders' equity at Jun. 30, 2022	7,745,216	$ 2,326	3,319,150	0	4,423,740
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share issuances (shares)		41
Dividends declared	(34,624)				(34,624)
Share repurchases (shares)		(4,379)
Share repurchases	(180,446)	$ (44)			(180,402)
Cash paid for shares withheld for taxes	(711)				(711)
Share-based compensation	6,640		6,640
Net income	627,928				627,928
Other comprehensive income	0
Ending shareholders' equity (shares) at Sep. 30, 2022		228,232
Ending shareholders' equity at Sep. 30, 2022	$ 8,164,003	$ 2,282	$ 3,325,790	$ 0	$ 4,835,931