Note 6 - Acquisitions (Tables)

6 Months Ended

Oct. 31, 2013

Business Combinations [Abstract]

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]

Assets acquired:
Inventories	$	1,294
Property and equipment		18,384
Total assets		19,678
Liabilities assumed:
Accrued expenses		101
Total liabilities		101
Net tangible assets acquired, net of cash		19,577
Goodwill and other intangible assets		4,965
Total consideration paid, net of cash acquired	$	24,542

Business Acquisition, Pro Forma Information [Table Text Block]

	Six months ended October 31,
	2013		2012
Total revenues	$	4,157,549		3,869,210
Net earnings		97,510		73,387
Earnings per common share:
Basic	$	2.54		1.92
Diluted	$	2.51		1.90