Note 1 - General (Details Textual) $ in Thousands		3 Months Ended		6 Months Ended
	Mar. 05, 2014 USD ($) shares	Jun. 30, 2015 USD ($) shares	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) shares	Jun. 30, 2014 USD ($)	Dec. 31, 2014 shares	Mar. 13, 2014 shares
Foreign Exchange Forward [Member]
Derivative, Loss on Derivative | $		$ 74		$ 598
Derivative, Gain on Derivative | $			$ 18		$ 18
Foreign Exchange Contract [Member]
Derivative Instrument, Maturity Period	1 year
IPO [Member]
Common Stock, Shares, Issued	5,300,436
Entity Incorporation, Date of Incorporation				Nov. 03, 2004
Operations Commenced Date				Jan. 01, 2005
Subsidiary or Equity Method Investee, Number		5		5
Common Stock, Shares, Issued		24,908,121		24,908,121		24,685,604
Common Stock, Shares Issued upon Exercise by Underwriters	500,436
Proceeds from Issuance of Common Stock | $	$ 106,071
Conversion of Convertible Preferred Stock to Common Stock at Initial Public Offering, Shares	15,082,141
Conversion of Preferred Stock Warrants to Common Stock Warrants, Shares	122,572
Class of Warrant or Right, Number of Securities Called by Warrants or Rights							107,217