Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenues, net of returns and allowances	$ 14,460	$ 20,633	$ 35,152	$ 43,858
Cost of sales	9,102	12,706	21,620	26,911
Gross profit	5,358	7,927	13,532	16,947
Selling, general and administrative	5,415	5,793	11,330	12,419
Research, development and engineering	915	713	1,537	1,579
Restructuring charges		173		1,037
Operating (loss) income	(972)	1,248	665	1,912
Loss on sale of subsidiary			(2,793)
Interest income and other, net	595	96	525	262
(Loss) income from continuing operations before income taxes	(377)	1,344	(1,603)	2,174
Income tax provision	166	332	207	914
(Loss) income from continuing operations, net of tax	(543)	1,012	(1,810)	1,260
Loss from discontinued operations, net of tax	(11,151)	(6,647)	(11,816)	(9,267)
Net loss	$ (11,694)	$ (5,635)	$ (13,626)	$ (8,007)
(Loss) Income Per Basic Share:
Basic (loss) income per share from continuing operations	$ (0.04)	$ 0.07	$ (0.13)	$ 0.09
Basic loss per share from discontinued operations	(0.79)	(0.47)	(0.83)	(0.65)
Net loss per basic share	(0.83)	(0.40)	(0.96)	(0.56)
(Loss) Income Per Diluted Share:
Diluted (loss) income per share from continuing operations	(0.04)	0.07	(0.13)	0.09
Diluted loss per share from discontinued operations	(0.79)	(0.47)	(0.83)	(0.65)
Net loss per diluted share	$ (0.83)	$ (0.40)	$ (0.96)	$ (0.56)
Weighted average shares outstanding - basic	14,150	14,228	14,193	14,224
Weighted average shares outstanding - diluted	14,150	14,258	14,193	14,255