DETAIL OF SELECTED BALANCE SHEET ACCOUNTS - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2017 |
Dec. 31, 2016 |
Jun. 30, 2016 |
Dec. 31, 2015 |
|
| Variable Interest Entity [Line Items] | |||||
| Cash and cash equivalents | $ 20,238 | $ 20,238 | $ 11,460 | ||
| Restricted cash | 5,114 | 5,114 | 536 | ||
| Total cash, cash equivalents, and restricted cash shown in the condensed consolidated statements of cash flows | 25,352 | 25,352 | $ 11,996 | $ 17,350 | $ 11,818 |
| West Africa | Variable Interest Entity, Primary Beneficiary | |||||
| Variable Interest Entity [Line Items] | |||||
| Restricted cash | 4,581 | 4,581 | |||
| Foreign exchange loss recognized | $ 765 | $ 765 |