Property and equipment- Depreciation and amortization (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Depreciation and amortization
Total depreciation and amortization of property and equipment	$ 16,014	$ 11,400	$ 30,999	$ 21,708
Asset impairment charge
Losses on disposals of property and equipment			276
Abandoned construction in progress projects
Asset impairment charge
Impairment losses			164
Network access
Depreciation and amortization
Total depreciation and amortization of property and equipment	9,354	6,205	17,729	11,462
Network operations
Depreciation and amortization
Total depreciation and amortization of property and equipment	4,131	3,255	8,286	6,450
Development and technology
Depreciation and amortization
Total depreciation and amortization of property and equipment	2,270	1,689	4,465	3,291
General and administrative
Depreciation and amortization
Total depreciation and amortization of property and equipment	$ 259	$ 251	$ 519	$ 505