Inventories - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Finished goods	$ 2,393	$ 2,704
Raw materials	2,250	1,928
Total inventories	4,643	4,632
Short-term portion	3,615	3,923
Long-term portion	1,028	709
Total inventories	$ 4,643	$ 4,632