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Segment information (Details) $ in Thousands	3 Months Ended
Segment information (Details) $ in Thousands	Mar. 31, 2022 USD ($) segment	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Geographic information
Number of operating segments \| segment	1
Revenues	$ 149,175	$ 146,777
Long-lived assets, net	456,430		$ 457,892
On-net
Geographic information
Revenues	112,634	109,947
Off-net
Geographic information
Revenues	36,387	36,723
Non-core
Geographic information
Revenues	154	107
North America
Geographic information
Revenues	118,292	116,396
Long-lived assets, net	330,769		331,537
North America \| On-net
Geographic information
Revenues	86,442	84,464
North America \| Off-net
Geographic information
Revenues	31,710	31,843
North America \| Non-core
Geographic information
Revenues	140	89
Europe and other
Geographic information
Long-lived assets, net	125,661		$ 126,355
Europe
Geographic information
Revenues	25,780	27,030
Europe \| On-net
Geographic information
Revenues	21,496	22,420
Europe \| Off-net
Geographic information
Revenues	4,274	4,592
Europe \| Non-core
Geographic information
Revenues	10	18
Asia Pacific
Geographic information
Revenues	3,481	2,444
Asia Pacific \| On-net
Geographic information
Revenues	3,141	2,173
Asia Pacific \| Off-net
Geographic information
Revenues	337	271
Asia Pacific \| Non-core
Geographic information
Revenues	3
Latin America
Geographic information
Revenues	1,451	828
Latin America \| On-net
Geographic information
Revenues	1,392	812
Latin America \| Off-net
Geographic information
Revenues	58	16
Latin America \| Non-core
Geographic information
Revenues	1
Africa
Geographic information
Revenues	171	79
Africa \| On-net
Geographic information
Revenues	163	78
Africa \| Off-net
Geographic information
Revenues	$ 8	$ 1