OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Revenue by Source (Details) - USD ($) $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 71,650	$ 72,960	$ 73,022	$ 73,873	$ 77,155	$ 82,928	$ 82,253	$ 73,822	$ 146,668	$ 156,075	$ 219,628	$ 239,003	$ 291,505	$ 316,158	$ 280,718
Colocation
Disaggregation of Revenue [Line Items]
Revenues													115,653	130,086	124,083
Network Services
Disaggregation of Revenue [Line Items]
Revenues													56,630	64,111	67,435
Cloud
Disaggregation of Revenue [Line Items]
Revenues													119,222	121,961	89,200
INAP US
Disaggregation of Revenue [Line Items]
Revenues													228,744	247,146	215,770
INAP US | Colocation
Disaggregation of Revenue [Line Items]
Revenues													109,850	124,244
INAP US | Network Services
Disaggregation of Revenue [Line Items]
Revenues													45,589	52,748
INAP US | Cloud
Disaggregation of Revenue [Line Items]
Revenues													73,305	70,154
INAP INTL
Disaggregation of Revenue [Line Items]
Revenues													62,761	69,012	$ 64,948
INAP INTL | Colocation
Disaggregation of Revenue [Line Items]
Revenues													5,803	5,842
INAP INTL | Network Services
Disaggregation of Revenue [Line Items]
Revenues													11,041	11,363
INAP INTL | Cloud
Disaggregation of Revenue [Line Items]
Revenues													$ 45,917	$ 51,807