Property and equipment- Depreciation and amortization (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Depreciation and amortization
Total depreciation and amortization of property and equipment	$ 14,985	$ 10,308
Network access
Depreciation and amortization
Total depreciation and amortization of property and equipment	8,375	5,257
Network operations
Depreciation and amortization
Total depreciation and amortization of property and equipment	4,155	3,195
Development and technology
Depreciation and amortization
Total depreciation and amortization of property and equipment	2,195	1,602
General and administrative
Depreciation and amortization
Total depreciation and amortization of property and equipment	$ 260	$ 254