Revenue from Contracts with Customers - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | |
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Mar. 31, 2018 |
Mar. 31, 2017 |
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| Concentration Risk [Line Items] | ||
| Revenue | $ 33,739 | $ 30,570 |
| Revenue | Product Concentration | Turnkey Energy Conservation Projects | ||
| Concentration Risk [Line Items] | ||
| Concentration percentage | 29.00% | |
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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 For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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