Segment Reporting (Summary Of Data By Industry Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue, net	$ 26,893	$ 29,566	$ 85,800	$ 83,590
Impairment loss			(3,765)
Income (loss) from continuing operations before income taxes and discontinued operations	(203)	2,105	(2,497)	5,907
Depreciation and amortization	820	697	2,448	2,107
Capital expenditures	1,428	1,888	3,787	3,496
Goodwill	9,551		9,551		$ 10,808
Body Worn Devices [Member]
Segment Reporting Information [Line Items]
Revenue, net	25,383	28,076	80,924	78,263
Income (loss) from continuing operations before income taxes and discontinued operations	750	3,146	5,106	7,899
Depreciation and amortization	712	642	2,210	1,952
Capital expenditures	1,374	1,884	3,651	3,426
Identifiable assets (excluding goodwill)	103,158		103,158		97,725
Goodwill	9,551		9,551		9,551
Hearing Health DTEC [Member]
Segment Reporting Information [Line Items]
Revenue, net	1,510	1,490	4,876	5,327
Impairment loss			(3,765)
Income (loss) from continuing operations before income taxes and discontinued operations	(953)	(1,041)	(7,603)	(1,992)
Depreciation and amortization	108	55	238	155
Capital expenditures	54	$ 4	136	$ 70
Identifiable assets (excluding goodwill)	$ 2,732		$ 2,732		5,139
Goodwill					$ 1,257