DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk and Significant Customers (Details) - Customer Concentration Risk |
3 Months Ended | 6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
Dec. 31, 2016 |
|
| VAD A | Sales | |||||
| Revenue, Major Customer [Line Items] | |||||
| Significant customer, as a percentage | 13.90% | 13.90% | 14.40% | 13.60% | |
| VAD A | Accounts Receivable | |||||
| Revenue, Major Customer [Line Items] | |||||
| Significant customer, as a percentage | 19.80% | 22.40% | |||
| VAD B | Sales | |||||
| Revenue, Major Customer [Line Items] | |||||
| Significant customer, as a percentage | 18.20% | 12.60% | 18.80% | ||
| VAD B | Accounts Receivable | |||||
| Revenue, Major Customer [Line Items] | |||||
| Significant customer, as a percentage | 15.50% | 14.40% | |||
| VAD C [Member] | Accounts Receivable | |||||
| Revenue, Major Customer [Line Items] | |||||
| Significant customer, as a percentage | 12.30% | 15.30% | |||