Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Operating activities:
Net earnings	$ 41,622	$ 49,867	$ 89,696	$ 118,403
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	26,283	21,645	51,648	43,476
Impairment of goodwill and long-lived assets	8,289		8,289
Provision for (benefit from) deferred income taxes	(583)	2,316	7,351	2,336
Bad debt (income) expense	41	232	(21)	151
Equity in net income of unconsolidated affiliates, net of distributions	2,952	(2,824)	(4,803)	1,074
Net (gain) loss on assets	(10,680)	(2,912)	(9,255)	1,484
Stock-based compensation	3,787	3,824	7,194	6,960
Changes in assets and liabilities, net of impact of acquisitions :
Receivables	(46,097)	(7,156)	16,581	9,798
Inventories	9,871	31,875	(24,825)	(18,523)
Prepaid expenses and other current assets	3,622	(1,737)	4,765	5,425
Other assets	(626)	1,165	(976)	2,411
Accounts payable and accrued expenses	(21,577)	(65,946)	(48,368)	(22,885)
Other liabilities	2,478	950	5,461	2,094
Net cash provided by operating activities	19,382	31,299	102,737	152,204
Investing activities:
Investment in property, plant and equipment	(23,678)	(14,730)	(41,691)	(31,046)
Acquisitions, net of cash acquired	(523)		(285,028)
Proceeds from sale of assets	16,312	799	16,739	956
Net cash used by investing activities	(7,889)	(13,931)	(309,980)	(30,090)
Financing activities:
Net proceeds from (repayments of) short-term borrowings	302	(1,037)	600	(2,154)
Proceeds from long-term debt, net of issuance costs	(594)		197,685
Principal payments on long-term debt	(220)	(218)	(439)	(437)
Proceeds from issuance of common shares, net of tax withholdings	(722)	(2,849)	(3,996)	2,972
Payments to noncontrolling interests	(3,196)	(6,781)	(3,916)	(6,781)
Repurchase of common shares	(67,448)		(112,524)
Dividends paid	(13,256)	(12,828)	(26,034)	(24,722)
Net cash provided (used) by financing activities	(85,134)	(23,713)	51,376	(31,122)
Increase (decrease) in cash and cash equivalents	(73,641)	(6,345)	(155,867)	90,992
Cash and cash equivalents at beginning of period	195,855	181,525	278,081	84,188
Cash and cash equivalents at end of period	$ 122,214	$ 175,180	$ 122,214	$ 175,180