Property and equipment- Depreciation and amortization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Depreciation and amortization
Total depreciation and amortization of property and equipment	$ 18,245	$ 13,093	$ 49,244	$ 34,801
Asset impairment charge
Losses on disposals of property and equipment			276
Abandoned construction in progress projects
Asset impairment charge
Impairment losses			166
Network access
Depreciation and amortization
Total depreciation and amortization of property and equipment	11,625	7,227	29,354	18,689
Network operations
Depreciation and amortization
Total depreciation and amortization of property and equipment	3,987	3,733	12,273	10,183
Development and technology
Depreciation and amortization
Total depreciation and amortization of property and equipment	2,375	1,881	6,840	5,172
General and administrative
Depreciation and amortization
Total depreciation and amortization of property and equipment	$ 258	$ 252	$ 777	$ 757