Discontinued Operations - Unconsolidated Subsidiaries - Statements of Operations (Details) - ULVAC Cryogenics, Inc. - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Total revenue	$ 94,652	$ 104,667	$ 68,054
Gross profit	34,982	41,241	23,586
Operating income	18,405	26,340	10,571
Net income	$ 13,345	$ 19,451	$ 7,492