Condensed Consolidated Financial Statements Detail - Additional Information 2 (Details) - USD ($) $ in Thousands  | 
3 Months Ended | 9 Months Ended | |
|---|---|---|---|
Sep. 30, 2017  | 
Sep. 30, 2017  | 
Sep. 30, 2016  | 
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| Property, Plant and Equipment [Line Items] | |||
| Total proceeds from sale of equipment and disposal of certain equipment | $ 1,614 | $ 45 | |
| Total carrying value of equipment sold and disposed | $ 100 | 500 | |
| Other Income (Expense) [Member] | |||
| Property, Plant and Equipment [Line Items] | |||
| Gain (loss) on sale and disposal of equipment | $ (100) | $ 1,100 | |
| X | ||||||||||
- Definition Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
- Definition The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
- 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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| X | ||||||||||
- Definition Equipment sold and disposed during period. No definition available. 
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- Details 
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