Note 11 - Business Segment Reporting - Sales by Geograhic Area (Details) - USD ($) $ in Millions	12 Months Ended
	May. 31, 2015	May. 25, 2014	May. 26, 2013
CANADA
Segment sales	$ 79.7	$ 46.6	$ 27.8
TAIWAN, PROVINCE OF CHINA
Segment sales	32.1	30.7	31.0
INDONESIA
Segment sales	9.0	9.6	21.0
CHINA
Segment sales	9.0	8.2	5.0
JAPAN
Segment sales	8.5	9.9	10.6
BELGIUM
Segment sales	6.8	13.1	16.6
All Other Countries [Member]
Segment sales	$ 18.4	$ 19.1	$ 20.8