Capital Expenditures

No definition available.

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

- Definition

Capital Expenditures Funded by Stimulus Grants

+ References

No definition available.

+ Details

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

- Definition

Represents the amount of grants received for the construction of assets which are recognized as a reduction of the cost of fixed assets, a reduction of depreciation expense over the useful lives of the assets, and as a reduction of capital expenditures.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

Name:	atni_MobilityFundLineItems
Namespace Prefix:	atni_
Data Type:	xbrli:stringItemType
Balance Type:	na
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

Amount of Mobility Funds received by the entity since inception of the grant.

+ References

No definition available.

+ Details

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

- 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

- Details

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

- Details

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

- Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=atni_OperatingExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	atni_GovernmentGrantsAxis=atni_StimulusGrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=stpr_VT
Namespace Prefix:
Data Type:	na
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GOVERNMENT GRANTS (Details) $ in Millions		1 Months Ended		12 Months Ended
GOVERNMENT GRANTS (Details) $ in Millions	Nov. 14, 2013 USD ($)	Oct. 31, 2014 USD ($)	Aug. 31, 2013 USD ($)	Dec. 31, 2015 USD ($) item
MOBILITY FUND GRANTS
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
Letter of credit sub-facility
MOBILITY FUND GRANTS
Letters of credit posted to USAC			$ 10.6	$ 10.6
Alltel Mobility Funds \| Letter of credit sub-facility
MOBILITY FUND GRANTS
Amount terminated	$ 19.9
Wholesale Mobility Funds
MOBILITY FUND GRANTS
Mobility Funds approved by FCC		$ 2.4	$ 21.7
Wholesale Mobility Funds \| U.S. Wireless
MOBILITY FUND GRANTS
Mobility Funds received				8.1
Wholesale Mobility Funds \| U.S. Wireless \| Operating Expenses [Member]
MOBILITY FUND GRANTS
Grant funds used to offset fixed asset related costs				1.0
Wholesale Mobility Funds \| U.S. Wireless \| Property, Plant and Equipment [Member]
MOBILITY FUND GRANTS
Grant funds used to offset fixed asset related costs				3.4
Wholesale Mobility Funds \| U.S. Wireless \| Other current liabilities
MOBILITY FUND GRANTS
Mobility Funds received				4.6
Wholesale Mobility Funds \| U.S. Wireless \| Other long-term liabilities
MOBILITY FUND GRANTS
Mobility Funds received				0.1
Stimulus Grants [Member] \| New York, Parts of Pennsylvania and Vermont
MOBILITY FUND GRANTS
Capital expenditures				35.8
Expenditures funded by stimulus grants				27.5
Stimulus Grants [Member] \| Navajo Nation
MOBILITY FUND GRANTS
Capital expenditures				7.6
Expenditures funded by stimulus grants				5.3
Stimulus Grants [Member] \| Vermont
MOBILITY FUND GRANTS
Capital expenditures				47.9
Expenditures funded by stimulus grants				$ 33.0