XML 67 R50.htm IDEA: XBRL DOCUMENT
v3.8.0.1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Grants (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 USD ($)
Minimum |
Accounting for grants |
Long-term power purchase agreements term | 10 years
Maximum |
Accounting for grants |
Long-term power purchase agreements term | 25 years
Mobility Funds |
Accounting for grants |
Mobility Funds Received | $ 21.1

X
- References No definition available. + Details
Name: | atni_AccountingForGrantsLineItems
Namespace Prefix: | atni_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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

X
- Definition Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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