Summary of Significant Accounting Policies - Retirement Benefits (Details) - USD ($) $ in Thousands |
6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Jun. 30, 2015 |
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| Summary of Significant Accounting Policies | ||||
| Pension contributions | $ 122 | $ 1,264 | $ 976 | $ 240 |
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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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