CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Non-controlling interest, net of tax (benefit) expense	$ 0.1	$ (0.2)	$ 0.2	$ (0.4)

Amount of current income tax expense (benefit) reported by noncontrolling interests.

No definition available.

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