Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Schedule of accrued expenses
Payroll and related benefits	$ 2,637	$ 4,248
Royalties	2,114	1,948
Professional fees	596	413
Other	1,409	1,351
Accrued Expenses, Total	$ 6,756	$ 7,960