Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, accumulated provision for doubtful accounts	$ 5,559	$ 6,861
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, authorized shares (in shares)	320,000	320,000
Common stock, shares issued (in shares)	257,003	257,003
Treasury stock, shares at cost (in shares)	1,741	1,832

Amount of allowance for credit loss on accounts receivable, classified as current.

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Face amount per share of no-par value common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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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 common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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