REVENUES - Summary of Revenue by Geography (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]
Net revenues	$ 81,962	$ 69,642	$ 156,163	$ 141,775
INAP US
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	65,168	55,206	123,319	111,751
INAP INTL
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	16,794	14,436	32,844	30,024
United States | INAP US
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	65,168	55,206	123,319	111,751
United States | INAP INTL
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	0	0	0	0
Canada | INAP US
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	0	0	0	0
Canada | INAP INTL
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	9,549	9,531	18,659	19,899
Other countries | INAP US
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	0	0	0	0
Other countries | INAP INTL
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	$ 7,245	$ 4,905	$ 14,185	$ 10,125