Supplemental Cash Flow Information (Tables)

12 Months Ended

May 31, 2012

Supplemental Cash Flow Information [Abstract]

Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]

	2012		2011			2010
	(in thousands)
Supplemental cash flow information:
Income taxes paid, net of refunds	$	74,199	$	44,254		$	72,649
Interest paid	$	13,631	$	15,537		$	12,728
Accrued liability for repurchase of common stock	$	—	$	—		$	1,920
Financing receivables:
Investment in equipment for financing leases	$	—	$	(54	)	$	(1,932	)
Principal collections from customers - financing leases	2,565		2,116			1,753
Net decrease (increase) in financing receivables	$	2,565	$	2,062		$	(179	)