Inventories (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Inventories
Raw materials	$ 4,116	$ 3,157
Work in process	8,929	8,322
Finished goods	7,759	5,738
Total inventories	20,804	17,217	11,292
Inventories disclosure
Inventory expensed	1,437
Cost of goods sold
Inventories disclosure
Inventory expensed	300
Research and development expenses
Inventories disclosure
Inventory expensed	$ 1,100