Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accounts Payable and Accrued Expenses
Trade accounts payable	$ 19,728	$ 15,191
Accrued cost of sales	914	1,058
Accrued compensation, benefits and payroll taxes	3,381	3,627
Income taxes payable	17	36
Other accrued expenses	4,908	1,163
Total accounts payable and accrued expenses	28,948	21,075
Expenses incurred in connection with IPO that have not yet been paid	$ 1,800