Note 15 - Segment and Geographic Information (Detail) - Sales by Geographic Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Aug. 19, 2011	Nov. 30, 2011	Nov. 30, 2012
Sales:
Net Sales	$ 82,056	$ 83,035	$ 74,910	$ 94,425	$ 167,210
Income (loss) from operations	8,299	(24,713)	(6,508)	(25,265)	22,241
Unaffiliated Customers [Member] | United States [Member]
Sales:
Net Sales	56,069	56,465	52,364	63,995	115,615
Unaffiliated Customers [Member] | Europe [Member]
Sales:
Net Sales	17,229	18,249	15,100	20,943	33,561
Unaffiliated Customers [Member] | Other Geographic Area [Member]
Sales:
Net Sales	8,758	8,321	7,446	9,487	18,034
Unaffiliated Customers [Member] | Consolidated [Member]
Sales:
Net Sales	82,056	83,035	74,910	94,425	167,210
Affiliates [Member] | United States [Member]
Sales:
Net Sales	6,847	4,052	3,679	4,426	13,246
Affiliates [Member] | Europe [Member]
Sales:
Net Sales	4,317	3,790	3,992	4,300	8,190
Affiliates [Member] | Other Geographic Area [Member]
Sales:
Net Sales	79	124	110	124	204
Affiliates [Member] | Geographical Intersegment, Eliminations [Member]
Sales:
Net Sales	(11,243)	(7,966)	(7,781)	(8,850)	(21,640)
Total [Member] | United States [Member]
Sales:
Net Sales	62,916	60,517	56,043	68,421	128,861
Total [Member] | Europe [Member]
Sales:
Net Sales	21,546	22,039	19,092	25,243	41,751
Total [Member] | Other Geographic Area [Member]
Sales:
Net Sales	8,837	8,445	7,556	9,611	18,238
Total [Member] | Geographical Intersegment, Eliminations [Member]
Sales:
Net Sales	(11,243)	(7,966)	(7,781)	(8,850)	(21,640)
Total [Member] | Consolidated [Member]
Sales:
Net Sales	82,056	83,035	74,910	94,425	167,210
United States [Member]
Sales:
Income (loss) from operations	5,629	(23,849)	(10,298)	(24,668)	15,594
Europe [Member]
Sales:
Income (loss) from operations	2,158	(1,287)	1,619	(1,056)	4,557
Other Geographic Area [Member]
Sales:
Income (loss) from operations	512	423	2,171	459	2,090
Consolidated [Member]
Sales:
Income (loss) from operations	$ 8,299	$ (24,713)	$ (6,508)	$ (25,265)	$ 22,241