Accrued expenses and other liabilities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accrued expenses and other liabilities
Revenue share	$ 3,384	$ 3,312
Salaries and wages	2,749	3,676
Accrued for construction-in-progress	1,420	1,003
Accrued partner network	1,273	1,134
Deferred rent	912	791
Other	3,039	1,103
Total accrued expenses and other liabilities	$ 12,777	$ 11,019