Represents the amount of pending awards of mobility fund grants to be secured against the issuance of debt instrument.

No definition available.

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Namespace Prefix:	atni_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the return on investment ensured by the government of Guyana, in which if the entity's return on investment falls below the ensured percentage, the Government of Guyana is obligated to reimburse any necessary amount.

+ References

No definition available.

+ Details

Name:	atni_LossContingencyMinimumReturnOnInvestmentEnsuredByGovernmentOfGuyana
Namespace Prefix:	atni_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period for which litigation proceedings and other disputes, while not conclusively resolved, have not been the subject of discussions or other significant activity.

+ References

No definition available.

+ Details

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Namespace Prefix:	atni_
Data Type:	xbrli:durationItemType
Balance Type:	na
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- Definition

Represents the amount of punitive damages that the plaintiff seeks in the legal matter.

+ References

No definition available.

+ Details

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Namespace Prefix:	atni_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the amount of renewal fee of telecommunications license.

+ References

No definition available.

+ Details

Name:	atni_LossContingencyRenewalFeeOfTelecommunicationsLicense
Namespace Prefix:	atni_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of spectrum fees paid as full settlement.

+ References

No definition available.

+ Details

Name:	atni_LossContingencySpectrumFeesPaid
Namespace Prefix:	atni_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of Mobility Fund support approved by Federal Communications Commission (FCC).

+ References

No definition available.

+ Details

Name:	atni_MobilityFundsApprovedByFederalCommunicationsCommission
Namespace Prefix:	atni_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the number of new funds created by Federal Communications Commission (FCC).

+ References

No definition available.

+ Details

Name:	atni_NumberOfNewFundsCreatedByCommunicationsCommission
Namespace Prefix:	atni_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period over which a portion of the Mobility Funds is used to offset the costs of supporting the networks.

+ References

No definition available.

+ Details

Name:	atni_PeriodOverWhichMobilityFundUsedToOffsetCostsOfSupportingTheNetworks
Namespace Prefix:	atni_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Amount of loss contingency liability.

+ References

+ Details

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

- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

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-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

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Name:	us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
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-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=atni_ContingencyRelatedToSpectrumFeesMember
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- Details

Name:	us-gaap_CreditFacilityAxis=atni_AmendedCreditFacilityMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	atni_TypeOfMobilityFundAxis=atni_AlltelMobilityFundsMember
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Data Type:	na
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- Details

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- Details

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COMMITMENTS AND CONTINGENCIES - Narrative (Details) AWG in Millions, $ in Millions				1 Months Ended					12 Months Ended
	Nov. 14, 2013 USD ($)	Jun. 17, 2013 USD ($)	Feb. 17, 2010 USD ($)	Oct. 31, 2014 USD ($)	Jan. 31, 2014 AWG	Jan. 31, 2014 USD ($)	Aug. 31, 2013 USD ($)	Nov. 30, 2007 USD ($)	Dec. 31, 2015 USD ($) item	Dec. 31, 2013 USD ($)	Dec. 31, 2011 USD ($)	Jan. 11, 2016 USD ($)	Jan. 10, 2016 USD ($)	Dec. 19, 2014 USD ($)
Commitments and contingencies
Number of new funds created by FCC \| item									2
Period over which a portion of the Mobility Funds is used to offset the costs of supporting the networks									5 years
Renewal fee of telecommunications license					AWG 7.2	$ 4.0
Contingency related to spectrum fees
Commitments and contingencies
Spectrum fees paid											$ 2.6
Amended Credit Facility [Member] \| Subsequent Event [Member]
Commitments and contingencies
Maximum borrowing capacity												$ 400.0	$ 275.0
Letter of credit sub-facility
Commitments and contingencies
Letters of credit posted to USAC							$ 10.6		$ 10.6
Outstanding letters of credit							10.6		10.6
Letter of credit sub-facility \| Amended Credit Facility [Member]
Commitments and contingencies
Maximum borrowing capacity									$ 55.0
Commitment fee (as a percent)										1.75%
Alltel Mobility Funds \| Letter of credit sub-facility
Commitments and contingencies
Termination of facility	$ 19.9
Alltel Mobility Funds \| Letter of credit sub-facility \| Amended Credit Facility [Member]
Commitments and contingencies
Maximum borrowing capacity														$ 25.0
Amount of pending awards of mobility fund grants		$ 68.8
Wholesale Mobility Funds
Commitments and contingencies
Mobility Funds approved by FCC				$ 2.4			$ 21.7
Universal Service Administrative Company \| Amended Credit Facility [Member]
Commitments and contingencies
Letters of credit posted to USAC		29.8
Outstanding letters of credit		$ 29.8
Universal Service Administrative Company \| Letter of credit sub-facility \| Amended Credit Facility [Member]
Commitments and contingencies
Letters of credit posted to USAC										$ 9.9
Outstanding letters of credit										$ 9.9
Lawsuit filed by CTL \| Minimum
Commitments and contingencies
Damages asserted								$ 200.0
Litigation proceedings and disputes in Guyana
Commitments and contingencies
Period for which litigation proceedings and other disputes have not been the subject of discussions or other significant activity									5 years
Lawsuit filed by GT&T against Digicel
Commitments and contingencies
Punitive damages			$ 5.0
Lawsuit filed by GT&T against Digicel \| Minimum
Commitments and contingencies
Damages asserted			$ 9.0
Legal claims regarding tax filings with the Guyana Revenue Authority
Commitments and contingencies
Future payments related to disputed tax assessments									$ 32.4
Accrued contingent liability									$ 5.0
Legal claims regarding tax filings with the Guyana Revenue Authority \| Minimum
Commitments and contingencies
Percentage of return on investment ensured by the government of Guyana									15.00%