Accrued expenses and other liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Accrued expenses and other liabilities
Revenue share	$ 3,870	$ 4,598
Salaries and wages	2,367	3,024
Accrued for construction-in-progress	6,261	2,717
Accrued partner network	749	736
Deferred rent	828	853
Holdback liabilities	1,600	1,875
Contingent consideration	1,584	980
Other	2,832	2,125
Total accrued expenses and other liabilities	$ 20,091	$ 16,908