Income Taxes - Components of provision for income taxes (Details 1) - USD ($) $ in Thousands  | 
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018  | 
Dec. 31, 2017  | 
Dec. 31, 2016  | 
|
| Current: | |||
| United States | $ (7,409) | $ 1,828 | $ (8,736) | 
| Total current | (12,780) | (2,789) | (10,902) | 
| Deferred: | |||
| United States | (1,912) | (8,439) | 3,684 | 
| Total deferred: | (1,687) | (7,953) | 3,684 | 
| Income tax expense | (14,467) | (10,742) | (7,218) | 
| BERMUDA | |||
| Current: | |||
| Foreign | 0 | 0 | 0 | 
| Deferred: | |||
| Foreign | 0 | 0 | 0 | 
| Foreign - Other | |||
| Current: | |||
| Foreign | (5,371) | (4,617) | (2,166) | 
| Deferred: | |||
| Foreign | $ 225 | $ 486 | $ 0 | 
| X | ||||||||||
- Definition Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of current foreign income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- References No definition available. 
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| X | ||||||||||
- Definition Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition Amount of deferred foreign income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- References No definition available. 
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| X | ||||||||||
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
- Details 
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- Details 
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