Note 2 - Revenue Information - Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue	$ 6,420	$ 6,971	$ 12,725	$ 14,260
Americas [Member]
Revenue	3,493	4,111	7,253	8,456
Asia Middle East and Australia [Member]
Revenue	1,969	1,861	3,833	3,899
Europe and Africa [Member]
Revenue	958	999	1,639	1,905
Audio Conferencing [Member]
Revenue	2,889	3,593	5,600	7,252
Microphones [Member]
Revenue	2,230	2,255	4,336	4,565
Video Products [Member]
Revenue	$ 1,301	$ 1,123	$ 2,789	$ 2,443

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Name:	us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration