Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - £ / shares	Sep. 30, 2018	Dec. 31, 2017
Common stock, nominal value (in GBP per share)	£ 0.006705	£ 0.006705
Common stock, shares authorized (in shares)	36,183,293	36,183,293
Common stock, shares issued (in shares)	26,337,963	25,661,634
Common stock, shares outstanding (in shares)	26,337,963	25,661,634

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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