REVENUES - Summary of Revenue by Source (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
INAP US
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	65,678	52,970	186,821	162,544
INAP US | Colocation
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	32,946	29,114	94,747	88,740
INAP US | Network services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	13,015	14,486	40,398	45,108
INAP US | Cloud
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	19,717	9,370	51,676	28,696
INAP INTL
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	17,294	15,937	52,314	48,138
INAP INTL | Colocation
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	1,372	1,166	4,349	3,745
INAP INTL | Network services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	2,719	2,281	8,482	5,329
INAP INTL | Cloud
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	$ 13,203	$ 12,490	$ 39,483	$ 39,064