SONOVA Gamma Linolenic Acid ("GLA") Safflower Oil Inventory - Summary of Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 45	$ 45
Finished goods	1,126	1,352
Inventories	$ 1,171	$ 1,397