Equity - Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 850,757	$ 983,465
Net income (loss)	20,795	(19,587)
Other comprehensive income (loss)	(21,699)	30,717
Issuances under stock plans	5,062	4,143
Common share repurchases	(29,837)	(28,408)
Stock-based compensation expense	31,819	30,958
Ending balance	856,897	987,571
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	82	82
Ending balance	82	82
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,823,710	1,761,383
Issuances under stock plans	(2,911)	(4,296)
Stock-based compensation expense	31,819	30,958
Ending balance	1,852,618	1,788,045
Accumulated Other Comprehensive Income, Net
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(39,867)	1,508
Other comprehensive income (loss)	(21,699)	30,717
Ending balance	(61,566)	32,225
Accumulated Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,755,432	1,647,284
Net income (loss)	20,795	(19,587)
Ending balance	1,776,227	1,613,980
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(2,688,600)	(2,426,792)
Issuances under stock plans	7,973	8,439
Common share repurchases	(29,837)	(28,408)
Ending balance	$ (2,710,464)	$ (2,446,761)
Accounting Standards Update 2016-16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU No. 2016-16			$ (13,717)
Accounting Standards Update 2016-16 \| Accumulated Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU No. 2016-16			$ (13,717)

Amount of increase to additional paid-in capital (APIC) from recognition of equity-based compensation.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Value, after forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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