Property and equipment (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Depreciation and amortization allocation of property and equipment
Total depreciation and amortization of property and equipment	$ 6,531	$ 4,734	$ 12,315	$ 8,867
Network access
Depreciation and amortization allocation of property and equipment
Total depreciation and amortization of property and equipment	4,511	3,205	8,373	6,082
Network operations
Depreciation and amortization allocation of property and equipment
Total depreciation and amortization of property and equipment	1,182	1,008	2,369	1,816
Development and technology
Depreciation and amortization allocation of property and equipment
Total depreciation and amortization of property and equipment	782	472	1,479	888
General and administrative
Depreciation and amortization allocation of property and equipment
Total depreciation and amortization of property and equipment	$ 56	$ 49	$ 94	$ 81