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Geographic and segment information: (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) segment	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Segment information
Number of operating segments | segment	1
Number of reportable segment | segment	1
Revenues	$ 975,766	$ 1,036,104	$ 940,922
Long lived assets, net	1,721,074	1,738,349
On-net
Segment information
Revenues	531,509	544,628	512,936
Off-net
Segment information
Revenues	397,470	454,107	393,493
Wavelength
Segment information
Revenues	38,453	19,196	5,653
Non-core
Segment information
Revenues	8,334	18,173	28,840
North America
Segment information
Revenues	819,523	888,001	802,690
Long lived assets, net	1,523,789	1,579,495
North America | On-net
Segment information
Revenues	400,765	424,437	401,213
North America | Off-net
Segment information
Revenues	373,289	426,857	367,210
North America | Wavelength
Segment information
Revenues	37,443	19,015	5,653
North America | Non-core
Segment information
Revenues	8,026	17,692	28,614
Europe
Segment information
Revenues	122,011	116,124	108,370
Europe | On-net
Segment information
Revenues	101,395	94,363	88,310
Europe | Off-net
Segment information
Revenues	19,455	21,242	19,913
Europe | Wavelength
Segment information
Revenues	944	172
Europe | Non-core
Segment information
Revenues	217	347	147
Oceania
Segment information
Revenues	24,836	23,318	21,427
Oceania | On-net
Segment information
Revenues	20,791	18,205	15,769
Oceania | Off-net
Segment information
Revenues	3,916	5,013	5,587
Oceania | Wavelength
Segment information
Revenues	66	9
Oceania | Non-core
Segment information
Revenues	63	91	71
South America
Segment information
Revenues	8,808	8,019	7,649
South America | On-net
Segment information
Revenues	8,072	7,080	6,957
South America | Off-net
Segment information
Revenues	708	896	684
South America | Non-core
Segment information
Revenues	28	43	8
Africa
Segment information
Revenues	588	642	786
Africa | On-net
Segment information
Revenues	486	543	687
Africa | Off-net
Segment information
Revenues	102	99	$ 99
Europe and other
Segment information
Long lived assets, net	$ 197,285	$ 158,854

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- Definition

Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

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