Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Operating activities:
Net earnings	$ 68,536	$ 34,995
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	21,831	21,440
Impairment of long-lived assets	0	3,000
Provision for (benefit from) deferred income taxes	20	(5,540)
Bad debt (income) expense	(81)	10
Equity in net income of unconsolidated affiliates, net of distributions	3,898	(5,513)
Net loss on sale of assets	4,396	1,606
Stock-based compensation	3,136	3,777
Changes in assets and liabilities:
Receivables	16,954	42,629
Inventories	(50,398)	(7,824)
Prepaid expenses and other current assets	7,162	11,166
Other assets	1,246	442
Accounts payable and accrued expenses	43,061	41,626
Other liabilities	1,144	(3,187)
Net cash provided by operating activities	120,905	138,627
Investing activities:
Investment in property, plant and equipment	(16,316)	(38,497)
Investments in unconsolidated affiliates		(1,687)
Proceeds from sale of assets	157	131
Net cash used by investing activities	(16,159)	(40,053)
Financing activities:
Net repayments of short-term borrowings	(1,117)	(68,511)
Proceeds from long-term debt		921
Principal payments on long-term debt	(219)	(208)
Proceeds from (payments for) issuance of common shares	5,821	(602)
Payments to noncontrolling interests		(3,336)
Repurchase of common shares		(27,582)
Dividends paid	(11,894)	(11,551)
Net cash used by financing activities	(7,409)	(110,869)
Increase (decrease) in cash and cash equivalents	97,337	(12,295)
Cash and cash equivalents at beginning of period	84,188	31,067
Cash and cash equivalents at end of period	$ 181,525	$ 18,772