CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income, Net [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]
Beginning balance at Dec. 31, 2019	$ 3,371,592	$ 6,547	$ 835,899	$ (37,799)	$ 2,865,939	$ (301,963)	$ 2,969
Beginning balance (in shares) at Dec. 31, 2019		65,472				(5,513)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises	353		26	0	0	$ 327	0
Stock option exercises (in shares)						15
Issuance of stock for equity awards, net of forfeitures	0		(5,690)	0	0	$ 5,690	0
Issuance of stock for equity awards, net of forfeitures (in shares)						103
Tax withholdings on equity award vesting	(3,193)					$ (3,193)	0
Tax withholdings on equity award vesting (in shares)						(39)
Amortization of unearned share-based compensation	12,066		12,066	0	0	$ 0	0
Total comprehensive income (loss), net of taxes	(301,843)			(7,836)	(294,750)	0	743
Return of investment to noncontrolling interests	(608)						(608)
Ending balance at Sep. 30, 2020	3,078,367	$ 6,547	842,301	(45,635)	2,571,189	$ (299,139)	3,104
Ending balance (in shares) at Sep. 30, 2020		65,472				(5,434)
Beginning balance at Jun. 30, 2020	3,051,984	$ 6,547	838,874	(41,117)	2,543,700	$ (299,124)	3,104
Beginning balance (in shares) at Jun. 30, 2020		65,472				(5,434)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock for equity awards, net of forfeitures			13	0	0	$ (13)	0
Issuance of stock for equity awards, net of forfeitures (in shares)						0
Tax withholdings on equity award vesting	(2)					$ (2)
Tax withholdings on equity award vesting (in shares)						0
Amortization of unearned share-based compensation	3,414		3,414	0	0	$ 0	0
Total comprehensive income (loss), net of taxes	23,175			(4,518)	27,489	0	204
Return of investment to noncontrolling interests	(204)						(204)
Ending balance at Sep. 30, 2020	3,078,367	$ 6,547	842,301	(45,635)	2,571,189	$ (299,139)	3,104
Ending balance (in shares) at Sep. 30, 2020		65,472				(5,434)
Beginning balance at Dec. 31, 2020	3,087,553	$ 6,547	844,979	(61,452)	2,593,393	$ (299,161)	3,247
Beginning balance (in shares) at Dec. 31, 2020		65,472				(5,434)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises	629		21	0	0	$ 608	0
Stock option exercises (in shares)						12
Issuance of stock for equity awards, net of forfeitures			(6,206)	0	0	$ 6,206	0
Issuance of stock for equity awards, net of forfeitures (in shares)						113
Tax withholdings on equity award vesting	(2,856)					$ (2,856)	0
Tax withholdings on equity award vesting (in shares)						(52)
Amortization of unearned share-based compensation	12,793		12,793
Total comprehensive income (loss), net of taxes	(251,131)			6,789	(257,915)		(5)
Return of investment to noncontrolling interests	(764)						(764)
Ending balance at Sep. 30, 2021	2,846,224	$ 6,547	851,587	(54,663)	2,335,478	$ (295,203)	2,478
Ending balance (in shares) at Sep. 30, 2021		65,472				(5,361)
Beginning balance at Jun. 30, 2021	3,105,329	$ 6,547	848,081	(57,683)	2,600,208	$ (295,463)	3,639
Beginning balance (in shares) at Jun. 30, 2021		65,472				(5,366)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises	124		(9)	0	0	$ 133	0
Stock option exercises (in shares)						2
Issuance of stock for equity awards, net of forfeitures			(130)	0	0	$ 130	0
Issuance of stock for equity awards, net of forfeitures (in shares)						3
Tax withholdings on equity award vesting	(3)					$ (3)	0
Tax withholdings on equity award vesting (in shares)						0
Amortization of unearned share-based compensation	3,645		3,645	0	0
Total comprehensive income (loss), net of taxes	(262,132)			3,020	(264,730)		(422)
Return of investment to noncontrolling interests	(739)						(739)
Ending balance at Sep. 30, 2021	$ 2,846,224	$ 6,547	$ 851,587	$ (54,663)	$ 2,335,478	$ (295,203)	$ 2,478
Ending balance (in shares) at Sep. 30, 2021		65,472				(5,361)