Note 15 - Segment and Geographic Information (Detail) - Sales by Geographic Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended	9 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Aug. 19, 2011	Feb. 29, 2012	Feb. 28, 2013
Net sales:
Net Sales	$ 86,192	$ 81,370	$ 74,910	$ 175,795	$ 253,402
Income (loss) from operations	12,844	9,113	(6,508)	(16,152)	35,085
Unaffiliated Customers [Member] | United States [Member]
Net sales:
Net Sales	60,201	56,007	52,364	120,002	175,816
Unaffiliated Customers [Member] | Europe [Member]
Net sales:
Net Sales	17,133	16,750	15,100	37,693	50,694
Unaffiliated Customers [Member] | Other Geographic Area [Member]
Net sales:
Net Sales	8,858	8,613	7,446	18,100	26,892
Unaffiliated Customers [Member] | Consolidated [Member]
Net sales:
Net Sales	86,192	81,370	74,910	175,795	253,402
Affiliates [Member] | United States [Member]
Net sales:
Net Sales	7,704	3,735	3,679	8,162	20,951
Affiliates [Member] | Europe [Member]
Net sales:
Net Sales	4,091	4,508	3,992	8,808	12,281
Affiliates [Member] | Other Geographic Area [Member]
Net sales:
Net Sales	41	83	110	207	245
Affiliates [Member] | Geographical Intersegment, Eliminations [Member]
Net sales:
Net Sales	(11,836)	(8,326)	(7,781)	(17,177)	(33,477)
Total [Member] | United States [Member]
Net sales:
Net Sales	67,905	59,742	56,043	128,164	196,767
Total [Member] | Europe [Member]
Net sales:
Net Sales	21,224	21,258	19,092	46,501	62,975
Total [Member] | Other Geographic Area [Member]
Net sales:
Net Sales	8,899	8,696	7,556	18,307	27,137
Total [Member] | Geographical Intersegment, Eliminations [Member]
Net sales:
Net Sales	(11,836)	(8,326)	(7,781)	(17,177)	(33,477)
Total [Member] | Consolidated [Member]
Net sales:
Net Sales	86,192	81,370	74,910	175,795	253,402
United States [Member]
Net sales:
Income (loss) from operations	11,424	5,250	(10,298)	(19,417)	27,017
Europe [Member]
Net sales:
Income (loss) from operations	972	1,393	1,619	336	5,529
Other Geographic Area [Member]
Net sales:
Income (loss) from operations	448	2,470	2,171	2,929	2,539
Consolidated [Member]
Net sales:
Income (loss) from operations	$ 12,844	$ 9,113	$ (6,508)	$ (16,152)	$ 35,085