REVENUES - Schedule of Current Impact from Adoption on Consolidated Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	$ 81,962	$ 69,642	$ 156,163	$ 141,775
Sales, general and administrative	19,602	15,571	39,456	32,135
Total operating costs and expenses	79,835	71,695	153,157	143,336
Income from operations	2,127	(2,053)	3,006	(1,561)
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	(13,759)	(19,389)	(27,692)	(27,131)
Net loss	(13,900)	(19,283)	(27,933)	(27,513)
Less net income attributable to non-controlling interest	23	0	50	0
Net loss attributable to INAP stockholders	(13,923)	(19,283)	(27,983)	(27,513)
Comprehensive loss	(13,862)	$ (19,191)	(27,861)	$ (27,263)
Balances without Adoption of ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	81,757		155,717
Sales, general and administrative	19,624		39,572
Total operating costs and expenses	79,857		153,273
Income from operations	1,900		2,444
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	(13,986)		(28,254)
Net loss	(14,127)		(28,495)
Less net income attributable to non-controlling interest	23		50
Net loss attributable to INAP stockholders	(14,150)		(28,545)
Comprehensive loss	(14,150)		(28,423)
Effect of Change Higher/ (Lower) | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	205		446
Sales, general and administrative	(22)		(116)
Total operating costs and expenses	(22)		(116)
Income from operations	227		562
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	227		562
Net loss	227		562
Less net income attributable to non-controlling interest	0		0
Net loss attributable to INAP stockholders	227		562
Comprehensive loss	$ 227		$ 562