Note 6 - Acquisitions (Details) - Allocation of the Purchase Price for Acquisitions (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Apr. 30, 2014
Note 6 - Acquisitions (Details) - Allocation of the Purchase Price for Acquisitions [Line Items]
Goodwill and other intangible assets	$ 126,931		$ 120,406
Total consideration paid, net of cash acquired	30,774	1,669
In Fiscal Year 2015 [Member]
Note 6 - Acquisitions (Details) - Allocation of the Purchase Price for Acquisitions [Line Items]
Inventories	2,208
Property and equipment	22,075
Total assets	24,283
Accrued expenses	34
Total liabilities	34
Net tangible assets acquired, net of cash	24,249
Goodwill and other intangible assets	6,525
Total consideration paid, net of cash acquired	$ 30,774