Note 3 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Total Revenue, net	$ 30,215	$ 23,602	$ 61,983	$ 45,105
Diabetes [Member]
Total Revenue, net	15,247	13,521	33,611	27,051
Interventional Catheters [Member]
Total Revenue, net	4,198	1,146	8,000	1,146
Medical Biotelemetry Other [Member]
Total Revenue, net	3,510	3,451	6,468	6,279
Hearing Health Direct To Consumer DTC Market [Member]
Total Revenue, net	950	1,387	1,887	2,560
Hearing Health Value Based ITEC [Member]
Total Revenue, net	2,570	1,365	4,555	2,109
Legacy OEM [Member]
Total Revenue, net	2,888	1,721	5,625	3,685
Professional Audio Communications [Member]
Total Revenue, net	852	1,011	1,837	2,275
Transferred at Point in Time [Member]
Total Revenue, net	13,517	8,479	25,553	14,810
Transferred at Point in Time [Member] | Diabetes [Member]
Total Revenue, net	0	0	0	0
Transferred at Point in Time [Member] | Interventional Catheters [Member]
Total Revenue, net	4,198	1,146	8,000	1,146
Transferred at Point in Time [Member] | Medical Biotelemetry Other [Member]
Total Revenue, net	2,059	1,849	3,649	3,035
Transferred at Point in Time [Member] | Hearing Health Direct To Consumer DTC Market [Member]
Total Revenue, net	950	1,387	1,887	2,560
Transferred at Point in Time [Member] | Hearing Health Value Based ITEC [Member]
Total Revenue, net	2,570	1,365	4,555	2,109
Transferred at Point in Time [Member] | Legacy OEM [Member]
Total Revenue, net	2,888	1,721	5,625	3,685
Transferred at Point in Time [Member] | Professional Audio Communications [Member]
Total Revenue, net	852	1,011	1,837	2,275
Transferred over Time [Member]
Total Revenue, net	16,698	15,123	36,430	30,295
Transferred over Time [Member] | Diabetes [Member]
Total Revenue, net	15,247	13,521	33,611	27,051
Transferred over Time [Member] | Interventional Catheters [Member]
Total Revenue, net	0	0	0	0
Transferred over Time [Member] | Medical Biotelemetry Other [Member]
Total Revenue, net	1,451	1,602	2,819	3,244
Transferred over Time [Member] | Hearing Health Direct To Consumer DTC Market [Member]
Total Revenue, net	0	0	0	0
Transferred over Time [Member] | Hearing Health Value Based ITEC [Member]
Total Revenue, net	0	0	0	0
Transferred over Time [Member] | Legacy OEM [Member]
Total Revenue, net	0	0	0	0
Transferred over Time [Member] | Professional Audio Communications [Member]
Total Revenue, net	$ 0	$ 0	$ 0	$ 0