CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative effect of accounting changes (Note 2)	Common Stock	Additional Paid-in Capital	Deferred Stock Units	Retained Earnings	Retained Earnings Cumulative effect of accounting changes (Note 2)	Accumulated Other Comprehensive (Loss) Income	Treasury Stock	Noncontrolling Interest
Balance beginning of period (in shares) at Dec. 31, 2018			105,087
Balance beginning of period at Dec. 31, 2018	$ (9,233)		$ 10,509	$ 1,138,216	$ 4,524	$ 1,167,928		$ (41,791)	$ (2,288,899)	$ 280
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	102,709					102,681				28
Other comprehensive loss, net	1,776							1,776
Repurchases of common stock, net	(61,135)								(61,135)
Common stock issued under stock plans (in shares)			258
Common stock issued under stock plans	11,419		$ 26	11,393
Share-based compensation cost	6,334			6,266	68
Balance end of period (in shares) at Mar. 31, 2019			105,345
Balance end of period at Mar. 31, 2019	51,870		$ 10,535	1,155,875	4,592	1,270,609		(40,015)	(2,350,034)	308
Balance beginning of period (in shares) at Dec. 31, 2018			105,087
Balance beginning of period at Dec. 31, 2018	(9,233)		$ 10,509	1,138,216	4,524	1,167,928		(41,791)	(2,288,899)	280
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	337,248
Other comprehensive loss, net	(3,774)
Balance end of period (in shares) at Sep. 30, 2019			105,594
Balance end of period at Sep. 30, 2019	202,722		$ 10,559	1,189,554	4,416	1,505,152		(45,565)	(2,461,698)	304
Balance beginning of period (in shares) at Mar. 31, 2019			105,345
Balance beginning of period at Mar. 31, 2019	51,870		$ 10,535	1,155,875	4,592	1,270,609		(40,015)	(2,350,034)	308
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	125,701					125,706				(5)
Other comprehensive loss, net	(568)							(568)
Repurchases of common stock, net	(20,343)								(20,343)
Common stock issued under stock plans (in shares)			133
Common stock issued under stock plans	7,991		$ 13	8,556	(578)
Deferred stock units activity	0			(324)	324
Share-based compensation cost	6,898			6,855	43
Balance end of period (in shares) at Jun. 30, 2019			105,478
Balance end of period at Jun. 30, 2019	171,549		$ 10,548	1,170,962	4,381	1,396,315		(40,583)	(2,370,377)	303
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	108,838					108,837				1
Other comprehensive loss, net	(4,982)							(4,982)
Repurchases of common stock, net	(91,321)								(91,321)
Common stock issued under stock plans (in shares)			116
Common stock issued under stock plans	9,247		$ 11	9,247	(11)
Share-based compensation cost	9,391			9,345	46
Balance end of period (in shares) at Sep. 30, 2019			105,594
Balance end of period at Sep. 30, 2019	$ 202,722		$ 10,559	1,189,554	4,416	1,505,152		(45,565)	(2,461,698)	304
Balance beginning of period (in shares) at Dec. 31, 2019	105,711		105,711
Balance beginning of period at Dec. 31, 2019	$ 177,825	$ (1,829)	$ 10,571	1,213,517	4,462	1,595,648	$ (1,829)	(46,182)	(2,600,543)	352
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	111,856					111,827				29
Other comprehensive loss, net	(9,064)							(9,064)
Repurchases of common stock, net	(187,767)								(187,767)
Common stock issued under stock plans (in shares)			203
Common stock issued under stock plans	9,750		$ 20	9,730
Share-based compensation cost	7,284			7,238	46
Balance end of period (in shares) at Mar. 31, 2020			105,914
Balance end of period at Mar. 31, 2020	$ 108,055		$ 10,591	1,230,485	4,508	1,705,646		(55,246)	(2,788,310)	381
Balance beginning of period (in shares) at Dec. 31, 2019	105,711		105,711
Balance beginning of period at Dec. 31, 2019	$ 177,825	$ (1,829)	$ 10,571	1,213,517	4,462	1,595,648	$ (1,829)	(46,182)	(2,600,543)	352
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	407,173
Other comprehensive loss, net	$ (15,743)
Balance end of period (in shares) at Sep. 30, 2020	106,282		106,282
Balance end of period at Sep. 30, 2020	$ 441,115		$ 10,628	1,274,069	5,411	2,000,805		(61,925)	(2,788,412)	539
Balance beginning of period (in shares) at Mar. 31, 2020			105,914
Balance beginning of period at Mar. 31, 2020	108,055		$ 10,591	1,230,485	4,508	1,705,646		(55,246)	(2,788,310)	381
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	148,996					148,940				56
Other comprehensive loss, net	(1,786)							(1,786)
Issuances of common stock, net	258								258
Common stock issued under stock plans (in shares)			117
Common stock issued under stock plans	10,080		$ 12	10,068
Deferred stock units activity	0			(894)	894
Share-based compensation cost	7,797			7,797
Balance end of period (in shares) at Jun. 30, 2020			106,031
Balance end of period at Jun. 30, 2020	273,400		$ 10,603	1,247,456	5,402	1,854,586		(57,032)	(2,788,052)	437
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	146,321					146,219				102
Other comprehensive loss, net	(4,893)							(4,893)
Repurchases of common stock, net	(360)								(360)
Common stock issued under stock plans (in shares)			251
Common stock issued under stock plans	18,719		$ 25	18,706	(12)
Share-based compensation cost	$ 7,928			7,907	21
Balance end of period (in shares) at Sep. 30, 2020	106,282		106,282
Balance end of period at Sep. 30, 2020	$ 441,115		$ 10,628	$ 1,274,069	$ 5,411	$ 2,000,805		$ (61,925)	$ (2,788,412)	$ 539