Revenue By Market (Schedule Of Net Revenue By Market) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue, Major Customer [Line Items]
Total Net Revenue	$ 26,893	$ 29,566	$ 85,800	$ 83,590
Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	7,794	10,210	25,016	28,103
Products and Services Transferred over Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	19,099	19,356	60,784	55,487
Medical Biotelemetry, Diabetes [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	15,723	16,662	50,837	47,531
Medical Biotelemetry, Diabetes [Member] | Products and Services Transferred over Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	15,723	16,662	50,837	47,531
Medical Biotelemetry, Other Medical [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	3,376	2,694	9,947	7,956
Medical Biotelemetry, Other Medical [Member] | Products and Services Transferred over Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	3,376	2,694	9,947	7,956
Hearing Health Value Based DTEC [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	1,510	1,490	4,876	5,327
Hearing Health Value Based DTEC [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	1,510	1,490	4,876	5,327
Hearing Health Value Based ITEC [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	2,443	3,660	7,419	8,923
Hearing Health Value Based ITEC [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	2,443	3,660	7,419	8,923
Legacy OEM [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	2,405	3,056	7,749	8,500
Legacy OEM [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	2,405	3,056	7,749	8,500
Professional Audio Communications [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	1,436	2,004	4,972	5,353
Professional Audio Communications [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	$ 1,436	$ 2,004	$ 4,972	$ 5,353