Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheets
Preferred stock, shares authorized	500,000us-gaap_PreferredStockSharesAuthorized	500,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, shares issued	0us-gaap_PreferredStockSharesIssued	0us-gaap_PreferredStockSharesIssued
Preferred stock, shares outstanding	0us-gaap_PreferredStockSharesOutstanding	0us-gaap_PreferredStockSharesOutstanding
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	120,000,000us-gaap_CommonStockSharesAuthorized	120,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	40,360,069us-gaap_CommonStockSharesIssued	39,666,195us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	40,360,069us-gaap_CommonStockSharesOutstanding	39,666,195us-gaap_CommonStockSharesOutstanding

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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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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