Other Balance Sheet Information - Summary of Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials and purchased parts	$ 72,820	$ 60,979
Work-in-process	11,273	16,090
Finished goods	21,211	15,503
Inventory, net	105,304	92,572
Reserves for excess and obsolete inventory	$ 23,900	$ 24,800