DESCRIPTION OF THE COMPANY AND NATURE OF OPERATIONS - Narrative (Details) $ in Thousands, ft² in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) ft² data_center	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of metropolitan markets | data_center	21
Area under lease | ft²	1.0
Area of data centers | ft²	0.6
Accumulated deficit | $	$ 1,363,019	$ 1,344,566	$ 1,329,086	$ 1,313,826	$ 1,300,519	$ 1,323,723
Working capital deficit | $	$ 5,900