Note 14 - Segment and Geographic Information - Segment and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
UNITED STATES
Net Revenues	$ 20,185	$ 19,317	$ 39,686	$ 39,450
FRANCE
Net Revenues	2,121	2,302	5,571	4,342
GERMANY
Net Revenues	8,960	8,845	17,559	16,922
UNITED KINGDOM
Net Revenues	3,209	3,494	6,836	6,714
Other Europe and the Middle East Regions [Member]
Net Revenues	7,285	8,663	15,454	17,319
CHINA
Net Revenues	21,218	20,053	43,858	41,288
JAPAN
Net Revenues	1,708	2,402	3,426	5,724
KOREA, REPUBLIC OF
Net Revenues	4,353	6,089	9,048	12,225
MALAYSIA [Member]
Net Revenues	1,288	1,322	2,092	2,564
SINGAPORE
Net Revenues	3,577	3,020	6,584	6,137
THAILAND
Net Revenues	1,040	992	1,851	2,035
Other Asia Pacific Regions [Member]
Net Revenues	1,403	1,609	3,150	3,093
INDIA
Net Revenues	1,207	909	2,107	2,041
Other Rest of the World [Member]
Net Revenues	1,075	1,240	2,045	2,450
Net Revenues	$ 78,629	$ 80,257	$ 159,267	$ 162,304