CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Deferred Stock Units	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting changes	$ (12,648)				$ (12,648)
Beginning balance, adjusted	(66,490)	$ 10,428	$ 1,073,931	$ 5,988	790,897	$ (36,470)	$ (1,911,528)	$ 264
Balance beginning of period (in shares) at Dec. 31, 2017		104,275
Balance beginning of period at Dec. 31, 2017	(53,842)	$ 10,428	1,073,931	5,988	803,545	(36,470)	(1,911,528)	264
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	89,476				89,451			25
Other comprehensive income, net	2,264					2,264
Repurchases of common stock, net	(94,285)						(94,285)
Common stock issued under stock plans (in shares)		401
Common stock issued under stock plans	14,092	$ 40	14,311	(259)
Share-based compensation cost	5,960		5,917	43
Balance end of period (in shares) at Mar. 31, 2018		104,676
Balance end of period at Mar. 31, 2018	(48,983)	$ 10,468	1,094,159	5,772	880,348	(34,206)	(2,005,813)	289
Balance beginning of period (in shares) at Dec. 31, 2017		104,275
Balance beginning of period at Dec. 31, 2017	(53,842)	$ 10,428	1,073,931	5,988	803,545	(36,470)	(1,911,528)	264
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	198,156
Other comprehensive income, net	(6,089)
Balance end of period (in shares) at Jun. 30, 2018		104,847
Balance end of period at Jun. 30, 2018	(40,849)	$ 10,485	1,109,157	4,398	989,039	(42,559)	(2,111,647)	278
Balance beginning of period (in shares) at Mar. 31, 2018		104,676
Balance beginning of period at Mar. 31, 2018	(48,983)	$ 10,468	1,094,159	5,772	880,348	(34,206)	(2,005,813)	289
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	108,680				108,691			(11)
Other comprehensive income, net	(8,353)					(8,353)
Repurchases of common stock, net	(105,834)						(105,834)
Common stock issued under stock plans (in shares)		171
Common stock issued under stock plans	7,249	$ 17	9,053	(1,821)
Deferred stock units activity	0		(385)	385
Share-based compensation cost	6,392		6,330	62
Balance end of period (in shares) at Jun. 30, 2018		104,847
Balance end of period at Jun. 30, 2018	$ (40,849)	$ 10,485	1,109,157	4,398	989,039	(42,559)	(2,111,647)	278
Balance beginning of period (in shares) at Dec. 31, 2018	105,087	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	102,709				102,681			28
Other comprehensive income, 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	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	228,410
Other comprehensive income, net	$ 1,208
Balance end of period (in shares) at Jun. 30, 2019	105,478	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
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	125,701				125,706			(5)
Other comprehensive income, 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			(324)	324
Share-based compensation cost	$ 6,898		6,855	43
Balance end of period (in shares) at Jun. 30, 2019	105,478	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