Note 4 - Accrued Liabilities (Details) - Accrued Liabilities (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	$ 7,574	$ 5,915
Deferred Revenue And Customer Prepayments [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	2,742	2,198
Stock Rotation Reserve [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	1,092	961
Legal Expenses And Settlement Cost [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	954	402
Sales Rebate [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	884	575
Commissions [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	536	464
Warranty [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	334	331
Other Liability [Member]
Note 4 - Accrued Liabilities (Details) - Accrued Liabilities [Line Items]
Accrued Liabililties	$ 1,032	$ 984