Components of Inventories (Detail) - USD ($) $ in Thousands	Jul. 01, 2017	Dec. 31, 2016
Current inventory:
Raw materials	$ 34,974	$ 35,314
Work in process	8,705	8,131
Finished goods	12,652	9,054
Total current inventory	56,331	52,499
Long term inventory	9,033	6,316
Total inventory	$ 65,364	$ 58,815