Schedule of Inventories at Cost Net of Reserves (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Inventory [Line Items]
Raw materials	$ 2,949	$ 2,949
Work in progress	6,863	7,331
Finished goods	1,290	1,282
Inventory at cost	11,102	11,562
Inventory reserves	(9,527)	(7,237)
Total	$ 1,575	$ 4,325