XML 107 R90.htm IDEA: XBRL DOCUMENT
v3.24.0.1

RETIREMENT PLANS - Net Assets and Allocations (Details) - Pension benefits - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Pension plan assets |  |  |
Fair value of plan assets | $ 71,504 | $ 71,552 | $ 103,718
Weighted-average asset allocations (as a percent) | 100.00% | 100.00% |
Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 37,776 | $ 48,639 |
Level 2 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | 33,728 | 22,913 |
Cash, cash equivalents, money markets and other |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 2,642 | $ 7,572 |
Weighted-average asset allocations (as a percent) | 4.00% | 11.00% |
Cash, cash equivalents, money markets and other | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 2,642 | $ 7,572 |
Common Stock |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 12,680 | $ 17,974 |
Weighted-average asset allocations (as a percent) | 18.00% | 25.00% |
Common Stock | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 12,680 | $ 17,974 |
Mutual funds - fixed income |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 8,836 | $ 10,732 |
Weighted-average asset allocations (as a percent) | 12.00% | 15.00% |
Mutual funds - fixed income | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 8,836 | $ 10,732 |
Mutual funds - equities |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 9,527 | $ 5,228 |
Weighted-average asset allocations (as a percent) | 13.00% | 7.00% |
Mutual funds - equities | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 9,527 | $ 5,228 |
Fixed income securities |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 33,728 | $ 22,913 |
Weighted-average asset allocations (as a percent) | 47.00% | 32.00% |
Fixed income securities | Level 2 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 33,728 | $ 22,913 |
Other plan assets |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 4,091 | $ 7,133 |
Weighted-average asset allocations (as a percent) | 6.00% | 10.00% |
Other plan assets | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 4,091 | $ 7,133 |

X
- Definition Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(02) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(i) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=atni_CashAndCashEquivalentsMoneyMarketsAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_FixedIncomeFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_FixedIncomeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=atni_OtherPlanAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |