CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 4,102	$ 4,480
Preferred stock par value	$ 1.00	$ 1.00
Preferred stock shares authorized	1,000,000	1,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock par value	$ 0.666	$ 0.666
Common stock shares authorized	70,000,000	70,000,000
Common stock shares issued	50,221,035	49,130,090
Common stock shares outstanding	50,221,035	49,130,090
Treasury stock, shares	1,457,206	1,457,206

A valuation allowance relating to a written agreement to receive money (at a specified future date(s) within one year from the reporting date (or the normal operating cycle, whichever is longer), consisting of principal as well as any accrued interest) for the portion that is expected to be uncollectible.

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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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Number of previously issued common shares repurchased by the issuing entity and held in treasury.

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