COMMITMENTS AND CONTINGENCIES (Details 2) (USD $)	12 Months Ended
Dec. 31, 2014 sqft	Dec. 31, 2013	Dec. 31, 2012
COMMITMENTS AND CONTINGENCIES
Area of lease (in square feet)	2,300,000atni_OperatingLeaseArea
Obligation for payments under leases
2015	$ 13,810,000
2016	13,047,000
2017	8,983,000
2018	6,372,000
2019	2,372,000
Thereafter	5,319,000
Total obligations under operating leases	49,903,000us-gaap_ContractualObligation
Rent expense
Rent expense	$ 15,000,000us-gaap_OperatingLeasesRentExpenseNet	$ 12,700,000us-gaap_OperatingLeasesRentExpenseNet	$ 13,700,000us-gaap_OperatingLeasesRentExpenseNet

Amount of contractual obligation maturing after the fourth fiscal year following the latest fiscal year.

No definition available.

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

- Definition

Represents the area of lease under non-cancelable operating leases.

+ References

No definition available.

+ Details

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Namespace Prefix:	atni_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation maturing in the fifth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation maturing in the fourth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation maturing in the next fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation maturing in the second fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation maturing in the third fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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

- Details

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

- Details

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

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717

+ Details

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