Note 3 - Supplemental Balance Sheet Information (Details) - Composition of Intangible Assets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross assets	$ 12,723	$ 12,654
Accumulated amortization	8,077	7,615
Net assets	4,646	5,039
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross assets	3,568	3,564
Net assets	3,568	3,564
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross assets	4,511	4,495
Accumulated amortization	3,941	3,702
Net assets	570	793
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross assets	4,033	3,998
Accumulated amortization	3,562	3,366
Net assets	471	632
Distributor Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross assets	393	380
Accumulated amortization	356	330
Net assets	37	50
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross assets	218	217
Accumulated amortization	$ 218	$ 217

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant