Inventories (Summary of Inventories) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Inventory Disclosure [Abstract]
Components, assemblies and parts	$ 94,988	$ 86,991
Customer projects in various stages of completion	37,412	30,225
Finished goods	11,087	10,512
Total inventories, net	$ 143,487	$ 127,728