Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Nov. 30, 2013	Nov. 30, 2012
Cash Flows From Operating Activities:
Net income	$ 175,303	$ 83,954
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	29,128	27,644
Amortization	15,776	14,565
Impairment on investment in Kemrock		51,092
Deferred income taxes	(8,500)	3,973
Stock-based compensation expense	9,622	8,135
Other	(1,229)	(9,655)
Changes in assets and liabilities, net of effect from purchases and sales of businesses:
Decrease in receivables	21,971	63,687
(Increase) in inventory	(44,020)	(25,936)
(Increase) decrease in prepaid expenses and other current and long-term assets	(750)	19,990
(Decrease) in accounts payable	(111,598)	(95,485)
(Decrease) in accrued compensation and benefits	(28,152)	(46,190)
(Decrease) increase in accrued loss reserves	(5,488)	3,984
Increase in other accrued liabilities	38,304	46,440
(Decrease) in contingent payment	(61,894)
Other	(6,641)	(18,577)
Cash Provided By Operating Activities	21,832	127,621
Cash Flows From Investing Activities:
Capital expenditures	(34,603)	(30,849)
Acquisition of businesses, net of cash acquired	(20,827)	(396,785)
Purchase of marketable securities	(33,770)	(68,442)
Proceeds from sales of marketable securities	19,672	58,194
Other	1,546	4,103
Cash (Used For) Investing Activities	(67,982)	(433,779)
Cash Flows From Financing Activities:
Additions to long-term and short-term debt	2,776	334,247
Reductions of long-term and short-term debt	(6,071)	(41,269)
Cash dividends	(61,796)	(58,054)
Repurchase of stock	(7,877)	(1,094)
Other	(1,330)	5,650
Cash (Used For) Provided By Financing Activities	(74,298)	239,480
Effect of Exchange Rate Changes on Cash and Cash Equivalents	1,066	12,650
Net Change in Cash and Cash Equivalents	(119,382)	(54,028)
Cash and Cash Equivalents at Beginning of Period	343,554	315,968
Cash and Cash Equivalents at End of Period	$ 224,172	$ 261,940