Discontinued Operations - Carrying Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Oct. 01, 2018	Sep. 30, 2018	Sep. 30, 2017
Disposal Group, Including Discontinued Operation, Assets [Abstract]
Total current assets of discontinued operation		$ 66,148
Total long-term assets of discontinued operation		59,052
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]
Total current liabilities of discontinued operation		18,537
Long-term liabilities of discontinued operation		698
Discontinued Operations, Held-for-sale | Semiconductor Cryogenics Business
Disposal Group, Including Discontinued Operation, Assets [Abstract]
Accounts receivable, net		27,852
Inventories		37,953
Other current assets		343
Total current assets of discontinued operation		66,148
Property, plant and equipment, net		1,081
Goodwill		26,485
Intangibles, net		14
Equity method investment		31,472
Total long-term assets of discontinued operation		59,052
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]
Accounts payable		11,149	$ 10,600
Deferred revenue	$ 1,532	1,052
Accrued warranty and retrofit costs		2,464
Other current liabilities		3,872
Total current liabilities of discontinued operation		18,537
Long-term liabilities of discontinued operation		$ 698