Stockholders' equity (Details) - $ / shares |
Sep. 30, 2015 |
Dec. 31, 2014 |
Oct. 16, 2013 |
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| Equity [Abstract] | |||
| Common stock, shares authorized (in shares) | 75,000,000 | 75,000,000 | |
| Common stock, par value per share (in dollars per share) | $ 0.0001 | $ 0.0001 | $ 0.0001 |
| Preferred stock, shares authorized (in shares) | 10,000,000 | 10,000,000 | |
| Preferred stock, par value per share (in dollars per share) | $ 0.0001 | $ 0.0001 | |
| Common stock, shares outstanding (in shares) | 24,972,515 | 24,940,195 | |
| Preferred stock, shares outstanding (in shares) | 0 | 0 |
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- Definition Face amount or stated value per share of common stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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