Retirement plans (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Retirement Benefits [Abstract] | ||
| Maximum employer annual contribution per employee, percent | 4.50% | |
| Contributions to plan | $ 238,680 | $ 231,945 |
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- References No definition available.
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- Definition Amount of cost for defined contribution plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. No definition available.
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