Summary of Significant Accounting Policies - Summary of Property Plant and Equipment and Rental Equipment with Associated Accumulated Depreciation (Details) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Property Plant And Equipment [Line Items] | ||
| Property and equipment | $ 64,568 | $ 67,215 |
| Accumulated depreciation | 44,465 | 42,016 |
| Property and equipment, net | 20,103 | 25,199 |
| Equipment | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment | 49,349 | 54,582 |
| Accumulated depreciation | 34,754 | 33,937 |
| Property and equipment, net | 14,595 | 20,645 |
| Other property and equipment | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment | 15,219 | 12,633 |
| Accumulated depreciation | 9,711 | 8,079 |
| Property and equipment, net | $ 5,508 | $ 4,554 |
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- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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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- Definition Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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