RELATED PARTY TRANSACTIONS (Details)	1 Months Ended
Oct. 31, 2014 USD ($) item
Tower Lease
Related Party Transaction
Annual lease payments \| $	$ 117,000
Initial Term	5 years
Number of additional renewal period \| item	2
Renewal period	5 years
Percentage of increase in rent	5.00%
Cornelius B. Prior Jr \| Tropical Tower
Related Party Transaction
Ownership interest	90.00%

Represents information pertaining to number of additional renewal period.

No definition available.

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

- Definition

Represents information pertaining to increase in percentage of rent every year.

+ References

No definition available.

+ Details

Name:	atni_OperatingLeaseRentPercentageIncrease
Namespace Prefix:	atni_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of related party annual lease payments.

+ References

No definition available.

+ Details

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

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=atni_TowerLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_BoardOfDirectorsChairmanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=atni_TropicalTowerLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: