Property, Plant and Equipment - Additional Information (Details) ft² in Thousands, $ in Millions |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2017
USD ($)
ft²
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
|
| Property, Plant and Equipment [Abstract] | |||
| Lease agreement expenses | $ | $ 1.0 | $ 2.5 | $ 5.9 |
| Office space area of leased premises | ft² | 8 | ||
| X | ||||||||||
- Definition Office Space Area No definition available.
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| X | ||||||||||
- Definition Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line. No definition available.
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| X | ||||||||||
- References No definition available.
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