Equity - Additional Information - Stock Issuance - Shares Issued to Terex Corporation (Detail) - USD ($) $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
Dec. 19, 2014 |
Dec. 31, 2014 |
Dec. 31, 2013 |
Dec. 31, 2015 |
|
| Class of Warrant or Right [Line Items] | ||||
| Common Stock, shares issued | 14,989,694 | 16,072,100 | ||
| Cash received | $ 12,500 | $ 13,927 | ||
| Securities Purchase Agreement [Member] | Minority Shareholders [Member] | ||||
| Class of Warrant or Right [Line Items] | ||||
| Common Stock, shares issued | 1,108,156 | |||
| Cash received | $ 12,500 | |||