Assets Held for Sale, Discontinued Operations and Disposals - Operating Results of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss	$ (11,151)	$ (665)	$ (184)	$ 1,154	$ (6,647)	$ (2,620)	$ (11,816)	$ (8,297)	$ (1,326)
Tempress and SoLayTec | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues, net of returns and allowances							7,442	25,139	76,395
Cost of sales							5,969	23,669	58,156
Gross profit							1,473	1,470	18,239
Selling, general and administrative							1,814	8,857	11,792
Research, development and engineering							540	3,039	4,944
Restructuring charges							37	567	897
Impairment charges							0	0	4,759
Operating loss							(918)	(10,993)	(4,153)
(Loss) gain on sale of subsidiary							(10,916)	1,614	0
Interest expense and other, net							(29)	(121)	(249)
Loss from discontinued operations before income taxes							(11,863)	(9,500)	(4,402)
Income benefit							(47)	(1,203)	(3,076)
Net loss							$ (11,816)	$ (8,297)	$ (1,326)