CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Allowance for doubtful accounts	$ 802	$ 1,296
Common stock par value	$ 0.01	$ 0.01
Common stock share authorized	74,687,845	72,187,845
Common stock share issued	47,952,733	47,567,010
Common stock shares, outstanding	47,039,212	46,738,540
Treasury stock share issued	913,521	828,472
Series A Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.01	$ 0.01
Cumulative preferred dividends	$ 0	$ 0
Convertible preferred stock, authorized	13,812,500	13,812,500
Convertible preferred stock, issued	13,812,500	13,812,500
Convertible preferred stock, outstanding	13,812,500	13,812,500
Series B Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.01	$ 0.01
Cumulative preferred dividends	$ 2,328	$ 812
Convertible preferred stock, authorized	6,608,700	6,608,700
Convertible preferred stock, issued	6,608,700	6,608,700
Convertible preferred stock, outstanding	6,608,700	6,608,700

Cumulative preferred dividends.

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Amount of allowance for credit loss on accounts receivable.

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Face amount or stated value per share of 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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Per share amount of par value or stated value of stock classified as temporary equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable.

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