REVENUES - Schedule of Current Impact from Adoption on Consolidated Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	$ 82,972	$ 68,907	$ 239,135	$ 210,682
Sales, general and administrative	18,170	15,331	57,625	47,466
Total operating costs and expenses	80,798	68,175	233,954	211,511
Income from operations	2,174	732	5,181	(829)
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	(14,919)	(11,764)	(42,610)	(38,895)
Net loss	(15,081)	(10,863)	(43,014)	(38,377)
Less net income attributable to non-controlling interest	25	32	75	32
Net loss attributable to INAP stockholders	(15,106)	(10,895)	(43,089)	(38,409)
Comprehensive loss	(15,204)	$ (10,986)	(43,065)	$ (38,250)
Balances without Adoption of ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	82,822		238,539
Sales, general and administrative	18,100		57,671
Total operating costs and expenses	80,728		234,000
Income from operations	2,094		4,539
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	(14,999)		(43,252)
Net loss	(15,161)		(43,656)
Less net income attributable to non-controlling interest	25		75
Net loss attributable to INAP stockholders	(15,186)		(43,731)
Comprehensive loss	(15,186)		(43,707)
Effect of Change Higher/ (Lower) | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	150		596
Sales, general and administrative	70		(46)
Total operating costs and expenses	70		(46)
Income from operations	80		642
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	80		642
Net loss	80		642
Less net income attributable to non-controlling interest	0		0
Net loss attributable to INAP stockholders	80		642
Comprehensive loss	$ 80		$ 642