DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Capitalized software
Property, Plant and Equipment [Line Items]
Useful Life	18 months
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful Life	7 years
Minimum | Computer and data center equipment
Property, Plant and Equipment [Line Items]
Useful Life	2 years
Maximum | Computer and data center equipment
Property, Plant and Equipment [Line Items]
Useful Life	3 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Useful Life	10 years