Accrued expenses and other liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accrued expenses and other liabilities
Revenue share	$ 3,916	$ 3,312
Salaries and wages	3,541	3,676
Accrued for construction-in-progress	850	1,003
Accrued partner network	1,394	1,134
Deferred rent	896	791
Other	2,955	1,103
Total accrued expenses and other liabilities	$ 13,552	$ 11,019