Stock incentive plans - Plans (Details) - shares |
Mar. 31, 2019 |
Dec. 31, 2018 |
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| Stock options | ||
| Stock incentive plans | ||
| Number of options outstanding | 300,000 | 304,000 |
| Stock options | 2011 Plan | ||
| Stock incentive plans | ||
| Number of options outstanding | 290,000 | |
| RSUs | 2011 Plan | ||
| Stock incentive plans | ||
| RSUs outstanding | 970,000 |
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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