Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 657,069	$ 637,835
Accumulated amortization	$ 460,841	$ 454,533
Ordinary shares, nominal value (in dollars per share)	$ 0.01	$ 0.01
Ordinary shares, shares issued (in shares)	45,255,680	44,539,433
Ordinary shares, shares outstanding (in shares)	45,255,680	44,539,433

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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