Note 13 - Segment and Geographic Information - Segment and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Net Revenues	$ 83,542	$ 80,638
UNITED STATES
Net Revenues	19,613	19,501
FRANCE
Net Revenues	1,935	3,450
GERMANY
Net Revenues	10,058	8,599
ITALY
Net Revenues	978	1,076
NETHERLANDS
Net Revenues	1,396	1,140
UNITED KINGDOM
Net Revenues	3,803	3,627
Other Europe and the Middle East Regions [Member]
Net Revenues	5,854	5,953
CHINA
Net Revenues	23,819	22,640
JAPAN
Net Revenues	2,119	1,718
SINGAPORE
Net Revenues	3,019	3,007
KOREA, REPUBLIC OF
Net Revenues	5,813	4,695
Other Asia Pacific Regions [Member]
Net Revenues	2,823	3,362
INDIA
Net Revenues	1,040	900
Other Rest of the World [Member]
Net Revenues	$ 1,272	$ 970