REVENUE RECOGNITION - Additional Information (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |
---|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
Dec. 31, 2018 |
|
Capitalized Contract Cost [Line Items] | |||
Deferred revenue | $ 21,161 | $ 25,452 | |
Deferred Revenue, Revenue Recognized | 25,300 | ||
Amortization of Deferred Charges | 5,000 | $ 7,000 | |
Revenue from Contract with Customers, Revenue constrained and ti be recognized in future periods | 13,000 | 13,700 | |
Prepaid expenses and other current assets | |||
Capitalized Contract Cost [Line Items] | |||
Deferred Costs | 2,800 | 2,900 | |
Other non-current assets | |||
Capitalized Contract Cost [Line Items] | |||
Deferred Costs | $ 10,500 | $ 11,000 |