Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 03, 2018
Document and Entity Information Abstract
Entity Registrant Name	Internap Corp
Entity Central Index Key	0001056386
Trading Symbol	inap
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		21,131,147