CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net revenues	$ 317,373,000	$ 280,718,000	$ 298,297,000
Operating costs and expenses:
Costs of sales and services, exclusive of depreciation and amortization	107,262,000	106,217,000	124,255,000
Costs of customer support	32,517,000	25,757,000	32,184,000
Sales, general and administrative	75,356,000	62,728,000	70,639,000
Depreciation and amortization	90,676,000	74,993,000	76,948,000
Goodwill impairment	0	0	80,105,000
Exit activities, restructuring and impairments	5,406,000	6,249,000	7,236,000
Total operating costs and expenses	311,217,000	275,944,000	391,367,000
Income (loss) from operations	6,156,000	4,774,000	(93,070,000)
Interest expense	68,132,000	50,476,000	30,909,000
(Gain) loss on foreign currency, net	(258,000)	525,000	485,000
Other income, net	0	0	(82,000)
Total non-operating expenses	67,874,000	51,001,000	31,312,000
Loss from continuing operations before income taxes, non-controlling interest and equity in (earnings) of equity-method investment	(61,718,000)	(46,227,000)	(124,382,000)
Provision for income taxes	657,000	253,000	530,000
Equity in earnings of equity-method investment, net of taxes	0	(1,207,000)	(170,000)
Net loss	(62,375,000)	(45,273,000)	(124,742,000)
Less net income attributable to non-controlling interest	125,000	70,000	0
Net loss attributable to INAP shareholders	(62,500,000)	(45,343,000)	(124,742,000)
Other comprehensive income (loss):
Foreign currency translation adjustment	259,000	23,000	(39,000)
Unrealized gain on foreign currency contracts	0	145,000	600,000
Unrealized gain on interest rate swap	0	0	728,000
Total other comprehensive income	259,000	168,000	1,289,000
Comprehensive loss	$ (62,241,000)	$ (45,175,000)	$ (123,453,000)
Basic and diluted net loss per share (in dollars per share)	$ (3.01)	$ (2.39)	$ (9.54)
Weighted average shares outstanding used in computing basic and diluted net loss per share (in shares)	20,732	18,993	13,083