EXIT ACTIVITIES AND RESTRUCTURING LIABILITIES - Exit activities and restructuring charges for Real estate obligations (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 4,703	$ 3,878
Initial Charges	4,024	239
Plan Adjustments	1,800	626
Cash Payments	(4,727)	(2,355)
Balance, end of period	5,800	2,388
Activity for 2017 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Initial Charges	4,024
Plan Adjustments	654
Cash Payments	(881)
Balance, end of period	3,797
Activity for 2016 restructuring charge: \| Severance
Restructuring Reserve [Roll Forward]
Balance, beginning of period	1,911
Initial Charges	0
Plan Adjustments	958
Cash Payments	(2,467)
Balance, end of period	402
Activity for 2016 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	933	0
Initial Charges	0	197
Plan Adjustments	76	12
Cash Payments	(730)	(149)
Balance, end of period	279	60
Activity for 2016 restructuring charge: \| Service contracts
Restructuring Reserve [Roll Forward]
Balance, beginning of period		0
Initial Charges		42
Plan Adjustments		(21)
Cash Payments		(21)
Balance, end of period		0
Activity for 2015 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	111	164
Initial Charges	0	0
Plan Adjustments	2	(10)
Cash Payments	(38)	(37)
Balance, end of period	75	117
Activity for 2015 restructuring charge: \| Service contracts
Restructuring Reserve [Roll Forward]
Balance, beginning of period	565	843
Initial Charges	0	0
Plan Adjustments	15	5
Cash Payments	(148)	(238)
Balance, end of period	432	610
Activity for 2014 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period	1,183	1,701
Initial Charges	0	0
Plan Adjustments	95	85
Cash Payments	(463)	(474)
Balance, end of period	$ 815	1,312
Activity for 2007 restructuring charge: \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance, beginning of period		1,170
Initial Charges		0
Plan Adjustments		555
Cash Payments		(1,436)
Balance, end of period		$ 289

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

No definition available.

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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=66902209&loc=d3e3536-108585

+ Details

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- 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=66902209&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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