Other Balance Sheet Information - Summary of Inventories (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials and purchased parts	$ 58,112	$ 62,441
Work-in-process	17,238	21,563
Finished goods	25,388	16,615
Inventory, net	100,738	100,619
Reserves for excess and obsolete inventory	$ 24,100	$ 23,800