REVENUES - Schedule of Current Impact from Adoption on Consolidated Income Statement (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Total revenues	$ 74,201	$ 72,133
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Costs of customer support	7,387	7,264
Sales, general and administrative	19,854	16,564
Depreciation and amortization	21,077	17,745
Exit activities, restructuring and impairments	(33)	1,023
Total operating costs and expenses	73,322	71,641
Income from operations	879	492
Non-operating expenses:
Interest expense	15,027	8,137
Gain on foreign currency, net	(215)	97
Total non-operating expenses	14,812	8,234
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	(13,933)	(7,742)
Provision for income taxes	100	518
Net loss	(14,033)	(8,230)
Less net income attributable to non-controlling interest	27	0
Net loss attributable to INAP stockholders	(14,060)	(8,230)
Other comprehensive income:
Foreign currency translation adjustment	61	73
Comprehensive loss	$ (13,999)	$ (8,072)
Basic and diluted net loss per share (in dollars per share)	$ (0.70)	$ (0.50)
Weighted average shares outstanding used in computing basic and diluted net loss per share (in shares)	20,052	16,087
Balances without Adoption of ASC 606
Revenues:
Total revenues	$ 73,960
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Costs of customer support	7,387
Sales, general and administrative	19,948
Depreciation and amortization	21,077
Exit activities, restructuring and impairments	(33)
Total operating costs and expenses	73,416
Income from operations	544
Non-operating expenses:
Interest expense	15,027
Gain on foreign currency, net	(215)
Total non-operating expenses	14,812
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	(14,268)
Provision for income taxes	100
Net loss	(14,368)
Less net income attributable to non-controlling interest	27
Net loss attributable to INAP stockholders	(14,395)
Other comprehensive income:
Foreign currency translation adjustment	61
Comprehensive loss	$ (14,334)
Basic and diluted net loss per share (in dollars per share)	$ (0.72)
Weighted average shares outstanding used in computing basic and diluted net loss per share (in shares)	20,052
Accounting Standards Update 2014-09 | Effect of Change Higher/ (Lower)
Revenues:
Total revenues	$ 241
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Costs of customer support	0
Sales, general and administrative	(94)
Depreciation and amortization	0
Exit activities, restructuring and impairments	0
Total operating costs and expenses	(94)
Income from operations	335
Non-operating expenses:
Interest expense	0
Gain on foreign currency, net	0
Total non-operating expenses	0
Loss before income taxes, non-controlling interest and equity in earnings of equity-method investment	335
Provision for income taxes	0
Net loss	335
Less net income attributable to non-controlling interest	0
Net loss attributable to INAP stockholders	335
Other comprehensive income:
Foreign currency translation adjustment	0
Comprehensive loss	$ 335
Basic and diluted net loss per share (in dollars per share)	$ 0.02
Weighted average shares outstanding used in computing basic and diluted net loss per share (in shares)
INAP US
Revenues:
Total revenues	$ 57,076	$ 55,461
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Direct costs of sales and services, exclusive of depreciation and amortization	18,435	23,547
INAP US | Balances without Adoption of ASC 606
Revenues:
Total revenues	56,835
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Direct costs of sales and services, exclusive of depreciation and amortization	18,435
INAP US | Accounting Standards Update 2014-09 | Effect of Change Higher/ (Lower)
Revenues:
Total revenues	241
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Direct costs of sales and services, exclusive of depreciation and amortization	0
INAP INTL
Revenues:
Total revenues	17,125	16,672
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Direct costs of sales and services, exclusive of depreciation and amortization	6,602	$ 5,498
INAP INTL | Balances without Adoption of ASC 606
Revenues:
Total revenues	17,125
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Direct costs of sales and services, exclusive of depreciation and amortization	6,602
INAP INTL | Accounting Standards Update 2014-09 | Effect of Change Higher/ (Lower)
Revenues:
Total revenues	0
Costs of sales and services, exclusive of depreciation and amortization, shown below:
Direct costs of sales and services, exclusive of depreciation and amortization	$ 0