Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Inventories
Finished products	$ 4,369	$ 10,018
Work in process and inventoried costs under long-term contracts	84,131	62,570
Materials and purchased parts	10,163	12,102
Customer advances	(10,948)	(18,328)
Net inventories	87,715	66,362
Costs incurred outside the scope of work or in advance of a contract award	4,300	700
General and administrative amounts for certain government contracts remaining in inventory	$ 2,500	$ 2,300