Property and equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Property and equipment
Total property and equipment	$ 721,340		$ 708,431
Less: accumulated depreciation and amortization	(336,704)		(328,188)
Total property and equipment, net	384,636		380,243
Depreciation and amortization expense
Total depreciation and amortization of property and equipment	18,646	$ 19,009
Network access
Depreciation and amortization expense
Total depreciation and amortization of property and equipment	10,950	11,582
Network operations
Depreciation and amortization expense
Total depreciation and amortization of property and equipment	4,667	4,386
Development and technology
Depreciation and amortization expense
Total depreciation and amortization of property and equipment	2,733	2,779
General and administrative
Depreciation and amortization expense
Total depreciation and amortization of property and equipment	296	$ 262
Leasehold improvements
Property and equipment
Total property and equipment	555,106		550,427
Construction in progress
Property and equipment
Total property and equipment	84,800		78,343
Software
Property and equipment
Total property and equipment	62,418		60,814
Computer equipment
Property and equipment
Total property and equipment	16,637		16,707
Furniture, fixtures and office equipment
Property and equipment
Total property and equipment	$ 2,379		$ 2,140