CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED BALANCE SHEETS
Property and equipment, Accumulated depreciation	$ 60,271	$ 60,697
Common stock, par value	$ 0	$ 0
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, issued (in shares)	60,672,034	65,897,866
Common stock, outstanding (in shares)	60,672,034	65,897,866

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

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