Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Property, Plant and Equipment [Line Items] | ||
| Depreciation expenses | $ 15,562 | $ 13,233 |
| Water Treatment Facilities [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Business acquisition, assets acquired and liabilities assumed, net | 4,172 | |
| Business acquisition, other current liabilities | 553 | |
| Business acquisition, other non-current liabilities | 3,619 | |
| Proceeds from sale leaseback facility | $ 4,172 | |
| Sale leaseback facility, term | 10 years | |