Note 15 - Segment and Geographic Information (Details) - Long-Lived Assets by Geographic Area (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Aug. 31, 2013		May 31, 2013
Long-lived tangible assets by geography:
Long-lived assets (excluding goodwill and intangibles)	$ 75,340		$ 76,381
Concentration of net assets by geography:
Concentration of net assets	639,103		644,706
United States [Member]
Long-lived tangible assets by geography:
Long-lived assets (excluding goodwill and intangibles)	55,171		57,184
Concentration of net assets by geography:
Concentration of net assets	484,416		485,968
Europe [Member]
Long-lived tangible assets by geography:
Long-lived assets (excluding goodwill and intangibles)	14,152	[1]	13,399	[1]
Concentration of net assets by geography:
Concentration of net assets	110,668		114,740
Canada [Member]
Long-lived tangible assets by geography:
Long-lived assets (excluding goodwill and intangibles)	4,446		4,511
Concentration of net assets by geography:
Concentration of net assets	32,564		32,910
Other Geographic Area [Member]
Long-lived tangible assets by geography:
Long-lived assets (excluding goodwill and intangibles)	1,571	[2]	1,287	[2]
Concentration of net assets by geography:
Concentration of net assets	$ 11,455		$ 11,088

[1] Long-lived assets located in any individual country within Europe were not material to the Company's consolidated long-lived assets.

[2] Primarily Japan and India