Represents the total amounts drawn down on issued letters of credit as of the reporting date.

No definition available.

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

- 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

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

- Definition

The period over which the calculation of spectrum fees is in dispute.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

Name:	atni_LossContingencyPunitiveDamages
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 Mobility Fund support approved by Federal Communications Commission (FCC).

+ References

No definition available.

+ Details

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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

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

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

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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

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

- 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

+ Details

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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)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 9

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

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

- Details

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

- Details

Name:	atni_TypeOfMobilityFundAxis=atni_WholesaleMobilityFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	atni_TypeOfMobilityFundAxis=atni_UniversalServiceAdministrativeCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
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- Details

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- Details

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- Details

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COMMITMENTS AND CONTINGENCIES (Details) - Debt Instrument, Name [Domain] AWG in Millions, $ in Millions		1 Months Ended				6 Months Ended
	Feb. 17, 2010 USD ($)	Jan. 31, 2014 AWG	Jan. 31, 2014 USD ($)	Aug. 31, 2013 USD ($)	Nov. 30, 2007 USD ($)	Jun. 30, 2015 USD ($) item	Dec. 31, 2014 USD ($)
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
Letter of credit sub-facility
Commitments and contingencies
Outstanding letters of credit						$ 10.6	$ 10.6
Wholesale Mobility Funds
Commitments and contingencies
Mobility Funds approved by FCC				$ 21.7
Commitment fee (as a percent)						1.75%
Wholesale Mobility Funds \| Letter of credit sub-facility
Commitments and contingencies
Outstanding letters of credit						$ 10.6
Universal Service Administrative Company \| Letter of credit sub-facility
Commitments and contingencies
Draw downs against issued letters of credit						$ 0.0
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
Loss Contingency Period Over Which Spectrum Fees Are Disputed						4 years
Damages asserted	$ 9.0
Punitive damages	$ 5.0
Legal claims regarding tax filings with the Guyana Revenue Authority
Commitments and contingencies
Future payments related to disputed tax assessments						$ 33.2
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%