Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011
Operating activities:
Net earnings	$ 136,835	$ 125,353	$ 124,034
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	66,469	55,873	61,058
Impairment of long-lived assets	6,488	355	4,386
Restructuring and other expense, non-cash			203
Joint venture transactions, non-cash			(21,652)
Provision for deferred income taxes	1,798	775	7,482
Bad debt expense	783	339	1,236
Equity in net income of unconsolidated affiliates, net of distributions	(10,948)	(1,019)	(19,188)
Net loss (gain) on sale of assets	1,121	(5,918)	652
Stock-based compensation	13,270	11,742	6,173
Excess tax benefits-stock-based compensation	(5,183)	(578)	(674)
Changes in assets and liabilities, net of impact of acquisitions:
Receivables	18,801	956	(96,056)
Inventories	77,115	17,310	(24,261)
Prepaid expenses and other current assets	871	8,478	(10,465)
Other assets	4,636	4,141	922
Accounts payable and accrued expenses	(47,483)	(45,847)	31,098
Other liabilities	8,404	1,689	6,947
Net cash provided by operating activities	272,977	173,649	71,895
Investing activities:
Investment in property, plant and equipment, net	(44,588)	(31,713)	(22,025)
Acquisitions, net of cash acquired	(175,225)	(239,851)	(31,705)
Distributions from (investments in) unconsolidated affiliates, net	863	45,879	(6,161)
Proceeds from sale of assets	16,974	37,089	20,614
Net cash used by investing activities	(201,976)	(188,596)	(39,277)
Financing activities:
Net proceeds from (payments of) short-term borrowings	(168,446)	97,626	132,956
Proceeds from long-term debt	150,000	5,880
Principal payments on long-term debt	(1,480)	(342)
Proceeds from issuance of common shares	37,914	11,116	4,827
Excess tax benefits-stock-based compensation	5,183	578	674
Payments to minority interest	(9,254)	(9,494)	(10,992)
Repurchase of common shares	(30,417)	(73,418)	(132,764)
Dividends paid	(44,144)	(32,138)	(30,168)
Net cash used by financing activities	(60,644)	(192)	(35,467)
Increase (decrease) in cash and cash equivalents	10,357	(15,139)	(2,849)
Cash and cash equivalents at beginning of year	41,028	56,167	59,016
Cash and cash equivalents at end of year	$ 51,385	$ 41,028	$ 56,167