Revenue By Market (Schedule Of Net Revenue By Market) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue, Major Customer [Line Items]
Total Net Revenue	$ 113,493	$ 113,948	$ 86,954
Medical Biotelemetry, Diabetes [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	68,606	65,197	43,365
Medical Biotelemetry, Other Medical [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	13,487	10,448	10,087
Hearing Health Value Based DTEC [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	6,120	6,858	6,492
Hearing Health Value Based ITEC [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	8,910	11,949	9,395
Legacy OEM [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	9,892	12,257	11,449
Professional Audio Communications [Member]
Revenue, Major Customer [Line Items]
Total Net Revenue	$ 6,478	$ 7,239	$ 6,166