IMPACT OF THE HURRICANES IRMA AND MARIA (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2017
IMPACT OF THE HURRICANES IRMA AND MARIA
Loss on disposal of network		$ 35,213
HURRICANES IRMA AND MARIA
IMPACT OF THE HURRICANES IRMA AND MARIA
Loss on disposal of network	$ 35,200	35,200
Additional operating expenses	1,400	$ 1,400
Potential business interruption insurance proceeds	$ 34,000
Discounted rate used for cash flows		14.50%
Impairment charges		$ 0
International Telecom segment \| HURRICANES IRMA AND MARIA
IMPACT OF THE HURRICANES IRMA AND MARIA
Service credit		$ 4,400

Represents the amount of additional operating expenses due to business interruption.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of insurance recovery limit due to business interruption.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of service credit to subscribers due to business interruption.

+ References

No definition available.

+ Details

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

- Definition

Represents the discounted rate used to compute cash flows.

+ References

No definition available.

+ Details

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

- Definition

The amount of loss on damaged asset from hurricanes.

+ References

No definition available.

+ Details

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

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- 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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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atni_InternationalTelecomMember
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