Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accrued Expenses
Defined contribution plan	$ 1,400	$ 1,088
Professional fees	4,971	0
Accrued payroll and related benefits	7,532	3,024
Sales and use tax	7,187	1,367
Bonus accrual	3,503	4,845
Interest payable	15,253	345
Advance from customer	1,753	0
Withholding taxes	2,929	0
Amount payable to noncontrolling shareholder	9,640	0
Other accrued expenses	4,845	2,229
Total accrued expenses	$ 59,013	$ 12,898