EXIT ACTIVITIES AND RESTRUCTURING - Schedule of Exit Activities and Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Reserve [Roll Forward]
Balance	$ 4,703	$ 3,878	$ 4,510
Initial Charges	3,359	3,568	1,538
Plan Adjustments	2,932	840	898
Cash Payments	(6,178)	(3,583)	(3,068)
Balance	4,816	4,703	3,878
Activity of 2017 Restructuring \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance	0
Initial Charges	3,359
Plan Adjustments	1,741
Cash Payments	(1,720)
Balance	3,380	0
Activity of 2016 Restructuring \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance	933	0
Initial Charges	0	1,082
Plan Adjustments	82	14
Cash Payments	(768)	(163)
Balance	247	933	0
Activity of 2016 Restructuring \| Severance
Restructuring Reserve [Roll Forward]
Balance	1,911	0
Initial Charges	0	2,444
Plan Adjustments	957	0
Cash Payments	(2,822)	(533)
Balance	46	1,911	0
Activity of 2016 Restructuring \| Service contracts
Restructuring Reserve [Roll Forward]
Balance	0	0
Initial Charges		42
Plan Adjustments		(21)
Cash Payments		(21)
Balance		0	0
Activity of 2015 Restructuring \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance	111	164	0
Initial Charges	0	0	270
Plan Adjustments	0	(13)	0
Cash Payments	(47)	(40)	(106)
Balance	64	111	164
Activity of 2015 Restructuring \| Service contracts
Restructuring Reserve [Roll Forward]
Balance	565	843	0
Initial Charges	0	0	1,268
Plan Adjustments	21	9	0
Cash Payments	(198)	(287)	(425)
Balance	388	565	843
Activity of 2014 Restructuring \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance	1,183	1,701	2,010
Initial Charges	0	0	0
Plan Adjustments	131	104	244
Cash Payments	(623)	(622)	(553)
Balance	691	1,183	1,701
Activity of 2007 Restructuring \| Real estate obligations
Restructuring Reserve [Roll Forward]
Balance	$ 0	1,170	2,325
Initial Charges		0	0
Plan Adjustments		747	660
Cash Payments		(1,917)	(1,815)
Balance		0	1,170
Other
Restructuring Reserve [Roll Forward]
Balance		$ 0	175
Initial Charges			0
Plan Adjustments			(6)
Cash Payments			(169)
Balance			$ 0

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

Name:	us-gaap_PaymentsForRestructuring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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

Name:	us-gaap_RestructuringReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

Name:	us-gaap_RestructuringReserveRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RestructuringPlanAxis=inap_Restructuring2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=inap_RealEstateObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=inap_Restructuring2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=inap_ServiceContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=inap_Restructuring2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=inap_Restructuring2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=inap_Restructuring2007Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=inap_OtherExitActivitiesAndRestructuringChargesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: