Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
Operating activities
Net earnings	$ 56,353	$ 34,865
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	19,460	14,987
Impairment of long-lived assets	4,641	1,570
Provision for deferred income taxes	(8,424)	4,679
Bad debt expense (income)	(481)	7
Equity in net income of unconsolidated affiliates, net of distributions	(5,915)	(7,358)
Net loss (gain) on sale of assets	(4,662)	2,310
Stock-based compensation	3,780	3,193
Excess tax benefits - stock-based compensation	(4,298)
Gain on previously held interest in TWB	(11,000)
Changes in assets and liabilities, net of impact of acquisitions:
Receivables	7,655	38,116
Inventories	515	17,019
Prepaid expenses and other current assets	(2,365)	(145)
Other assets	436	2,847
Accounts payable and accrued expenses	40,622	(39,573)
Other liabilities	(1,853)	(1,519)
Net cash provided by operating activities	94,464	70,998
Investing activities
Investment in property, plant and equipment, net	(13,354)	(16,705)
Acquisitions, net of cash acquired	52,957
Distributions from unconsolidated affiliates	5,555
Proceeds from sale of assets	7,647	6,585
Net cash provided (used) by investing activities	52,805	(10,120)
Financing activities
Net payments of short-term borrowings	(51,541)	(223,688)
Proceeds from long-term debt		150,000
Principal payments on long-term debt	(284)	(442)
Proceeds from issuance of common shares	2,201	10,855
Excess tax benefits - stock-based compensation	4,298
Payments to noncontrolling interest	(1,763)
Repurchase of common shares	(30,516)
Dividends paid		(8,150)
Net cash used by financing activities	(77,605)	(71,425)
Increase (decrease) in cash and cash equivalents	69,664	(10,547)
Cash and cash equivalents at beginning of period	51,385	41,028
Cash and cash equivalents at end of period	$ 121,049	$ 30,481