Discontinued Operations - Financial Results (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Net (loss) income	$ (117)	$ 8,149
Discontinued Operations, Held-for-sale \| Semiconductor Cryogenics Business
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total revenue		39,324
Total cost of revenue		22,565
Gross profit		16,759
Research and development		2,158
Selling, general and administrative	(257)	7,203
Total operating expenses	(257)	9,361
Operating income	257	7,398
Other (loss) income, net	(410)	289
(Loss) income before income taxes and earnings of equity method investment	(153)	7,687
Income tax provision	(36)	1,310
(Loss) income before equity in earnings of equity method investment	(117)	6,377
Equity in earnings of equity method investment		1,772
Net (loss) income	$ (117)	8,149
Discontinued Operations, Held-for-sale \| Semiconductor Cryogenics Business \| Products
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total revenue		28,786
Total cost of revenue		16,516
Discontinued Operations, Held-for-sale \| Semiconductor Cryogenics Business \| Services
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total revenue		10,538
Total cost of revenue		$ 6,049

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