Note 7 - Segment and Geographic Information (Details) - Customers with Sales and Accounts Receivable Greater than 10% - Customer Concentration Risk [Member]	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Distributor A [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Major Customer	23.00%	26.00%	24.00%	26.00%
Distributor A [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Major Customer			23.00%		31.00%
Distributor B [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Major Customer				10.00%
Distributor B [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Major Customer			10.00%		10.00%

[1] Represents less than 10%.