PROPERTY AND EQUIPMENT - Summary of property and equipment (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Property, Plant and Equipment [Line Items] | ||
| Total property and equipment | $ 15,247 | $ 11,427 |
| Accumulated depreciation and amortization | (9,225) | (6,632) |
| Property and equipment, net | 6,022 | 4,795 |
| Computer, network and other equipment | ||
| Property, Plant and Equipment [Line Items] | ||
| Total property and equipment | 8,805 | 7,150 |
| Monitoring equipment | ||
| Property, Plant and Equipment [Line Items] | ||
| Total property and equipment | 5,692 | 3,015 |
| Furniture and fixtures | ||
| Property, Plant and Equipment [Line Items] | ||
| Total property and equipment | 486 | 888 |
| Leasehold improvements | ||
| Property, Plant and Equipment [Line Items] | ||
| Total property and equipment | $ 264 | $ 374 |