NATURE OF BUSINESS AND ACCOUNTING POLICIES - Costs Incurred to Develop Software for Internal Use (Details) - USD ($) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Property, Plant and Equipment [Line Items] | |||
Impairment of internal use software | $ 0 | $ 0 | $ 0 |
Software costs capitalized during the period | 6,700,000 | 3,100,000 | 3,100,000 |
Capitalized computer software, net | 10,800,000 | 6,700,000 | |
Capitalized computer software, amortization | $ 2,600,000 | $ 1,600,000 | $ 1,000,000.0 |
Computer software | Minimum | |||
Property, Plant and Equipment [Line Items] | |||
Useful Life | 3 years | ||
Computer software | Maximum | |||
Property, Plant and Equipment [Line Items] | |||
Useful Life | 5 years |