Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2010
Operating activities:
Net earnings	$ 125,353	$ 124,034	$ 51,507
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	55,873	61,058	64,653
Impairment of long-lived assets	355	4,386	35,409
Restructuring and other expense, non-cash		203	3,408
Joint venture transactions, non-cash		(21,652)
Provision for deferred income taxes	775	7,482	(6,110)
Bad debt expense (income)	339	1,236	(900)
Equity in net income of unconsolidated affiliates, net of distributions	(1,019)	(19,188)	(12,007)
Net loss (gain) on sale of assets	(5,918)	652	(3,908)
Stock-based compensation	11,742	6,173	4,570
Excess tax benefits-stock-based compensation	(578)	(674)	(165)
Gain on acquisitions and sales of subsidiary investments			(891)
Changes in assets and liabilities, net of impact of acquisitions:
Receivables	956	(96,056)	(114,892)
Inventories	17,310	(24,261)	(64,499)
Prepaid expenses and other current assets	8,478	(10,465)	30,425
Other assets	4,141	922	205
Accounts payable and accrued expenses	(45,847)	31,098	125,613
Other liabilities	1,689	6,947	(1,999)
Net cash provided by operating activities	173,649	71,895	110,419
Investing activities:
Investment in property, plant and equipment, net	(31,713)	(22,025)	(34,319)
Acquisitions, net of cash acquired	(239,851)	(31,705)	(63,098)
Distributions from (investments in) unconsolidated affiliates, net	45,879	(6,161)	(483)
Proceeds from sale of assets	37,089	20,614	15,950
Net cash used by investing activities	(188,596)	(39,277)	(81,950)
Financing activities:
Net proceeds from (payments of) short-term borrowings	97,626	132,956	(980)
Proceeds from long-term debt	5,880		146,942
Principal payments on long-term debt	(342)		(138,013)
Proceeds from issuance of common shares	11,116	4,827	2,313
Excess tax benefits-stock-based compensation	578	674	165
Payments to minority interest	(9,494)	(10,992)	(4,539)
Repurchase of common shares	(73,418)	(132,764)
Dividends paid	(32,138)	(30,168)	(31,660)
Net cash used by financing activities	(192)	(35,467)	(25,772)
Increase (decrease) in cash and cash equivalents	(15,139)	(2,849)	2,697
Cash and cash equivalents at beginning of year	56,167	59,016	56,319
Cash and cash equivalents at end of year	$ 41,028	$ 56,167	$ 59,016