EXIT ACTIVITIES AND RESTRUCTURING LIABILITIES - Exit activities and restructuring charges for Real estate obligations (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 4,816	$ 4,703
Initial Charges	741	4,024
Plan Adjustments	371	1,367
Cash Payments	(2,676)	(2,466)
Balance, end of period	3,252	7,628
Activity for 2018 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Initial Charges	741
Plan Adjustments	45
Cash Payments	(163)
Balance, end of period	623
Activity for 2017 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	3,380	0
Initial Charges	0	4,024
Plan Adjustments	143	322
Cash Payments	(1,896)	0
Balance, end of period	1,627	4,346
Activity for 2016 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	247	933
Initial Charges	0	0
Plan Adjustments	14	379
Cash Payments	(77)	(370)
Balance, end of period	184	942
Activity for 2016 restructuring charge: \| Severance
Restructuring Reserve [Roll Forward]
Balance, beginning of period	46	1,911
Initial Charges	0	0
Plan Adjustments	34	605
Cash Payments	(34)	(1,679)
Balance, end of period	46	837
Activity for 2015 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	64	111
Initial Charges	0	0
Plan Adjustments	9	(8)
Cash Payments	(28)	(14)
Balance, end of period	45	89
Activity for 2015 restructuring charge: \| Service contracts
Restructuring Reserve [Roll Forward]
Balance, beginning of period	388	565
Initial Charges	0	0
Plan Adjustments	14	10
Cash Payments	(99)	(99)
Balance, end of period	303	476
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	112	59
Cash Payments	(379)	(304)
Balance, end of period	$ 424	$ 938

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
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- 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/disclosureRef
-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/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-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=115931487&loc=d3e140864-122747

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-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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-Topic 230
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-Section 45
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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+ 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://fasb.org/us-gaap/role/ref/legacyRef
-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

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-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

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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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