Accrued expenses and other liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accrued expenses and other liabilities
Accrued construction in progress	$ 8,744	$ 6,753
Accrued customer liabilities	5,904	4,651
Revenue share	4,857	5,611
Salaries and wages	4,581	3,001
Accrued partner network	1,846	1,022
Accrued taxes	1,800	1,761
Accrued professional fees	1,725	1,183
Other	6,203	3,741
Total accrued expenses and other liabilities	$ 35,660	$ 27,723