EXIT ACTIVITIES AND RESTRUCTURING LIABILITIES - Exit activities and restructuring charges for Real estate obligations (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 4,816	$ 4,703
Initial Charges	171	0
Plan Adjustments	201	979
Cash Payments	(1,389)	(1,386)
Balance, end of period	3,799	4,296
Activity for 2018 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Initial Charges	171
Plan Adjustments	9
Cash Payments	(23)
Balance, end of period	157
Activity for 2017 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	3,380
Initial Charges	0
Plan Adjustments	72
Cash Payments	(1,020)
Balance, end of period	2,432
Activity for 2016 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	247	1,911
Initial Charges	0	0
Plan Adjustments	7	566
Cash Payments	(38)	(993)
Balance, end of period	216	1,484
Activity for 2016 restructuring charge: \| Severance
Restructuring Reserve [Roll Forward]
Balance, beginning of period	46
Initial Charges	0
Plan Adjustments	34
Cash Payments	(34)
Balance, end of period	46
Activity for 2016 restructuring charge: \| Service contracts
Restructuring Reserve [Roll Forward]
Balance, beginning of period		933
Initial Charges		0
Plan Adjustments		378
Cash Payments		(187)
Balance, end of period		1,124
Activity for 2015 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	64	111
Initial Charges	0	0
Plan Adjustments	12	(4)
Cash Payments	(22)	(7)
Balance, end of period	54	100
Activity for 2015 restructuring charge: \| Service contracts
Restructuring Reserve [Roll Forward]
Balance, beginning of period	388	565
Initial Charges	0	0
Plan Adjustments	8	5
Cash Payments	(50)	(49)
Balance, end of period	346	521
Activity for 2014 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	691	1,183
Initial Charges	0	0
Plan Adjustments	59	34
Cash Payments	(202)	(150)
Balance, end of period	$ 548	$ 1,067

This element represents the value of restructuring reserve after adjustments in plan.

No definition available.

Name:	inap_RestructuringReserveSubsequentPlanAdjustments
Namespace Prefix:	inap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585

+ Details

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Period Type:	duration

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
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-Section S99
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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