Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Operating activities:
Net earnings	$ 56,922	$ 37,792	$ 54,467	$ 94,750
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	22,596	23,525	46,773	48,018
Impairment of long-lived assets	0	0	40,601	2,381
Provision for deferred income taxes	6,843	3,289	3,345	22,223
Bad debt expense	143	32	311	253
Equity in net income of unconsolidated affiliates, net of distributions	(19,879)	14,182	(14,797)	4,163
Net (gain) loss on sale of assets	(17)	(312)	601	2,403
Stock-based compensation	3,280	3,456	7,275	6,612
Loss on extinguishment of debt	0	0	4,034	0
Changes in assets and liabilities, net of impact of acquisitions:
Receivables	(5,456)	40,838	9,525	54,247
Inventories	43,601	5,866	87,883	(37,471)
Accounts payable	(20,743)	(72,974)	(57,977)	(70,160)
Accrued compensation and employee benefits	9,619	3,556	(13,596)	(27,378)
Other operating items, net	7,251	(14,546)	84	(24,892)
Net cash provided by operating activities	104,160	44,704	168,529	75,149
Investing activities:
Investment in property, plant and equipment	(28,381)	(21,741)	(50,555)	(41,175)
Acquisitions	(29,283)		(29,283)
Distributions from unconsolidated affiliate		55,201		55,201
Proceeds from sale of assets	23	170	9,199	20,447
Net cash provided (used) by investing activities	(57,641)	33,630	(70,639)	34,473
Financing activities:
Proceeds from long-term debt, net of issuance costs	(134)		101,464
Principal payments on long-term obligations and debt redemption costs	(490)	(371)	(154,467)	(801)
Payments for issuance of common shares, net of tax withholdings	(3,811)	(658)	(7,024)	(4,749)
Payments to noncontrolling interests	(1,453)	(4,007)	(1,453)	(6,327)
Repurchase of common shares		(63,581)	(29,599)	(100,433)
Dividends paid	(13,954)	(13,533)	(26,914)	(26,252)
Net cash used by financing activities	(19,842)	(82,150)	(117,993)	(138,562)
Increase (decrease) in cash and cash equivalents	26,677	(3,816)	(20,103)	(28,940)
Cash and cash equivalents at beginning of period	45,583	96,843	92,363	121,967
Cash and cash equivalents at end of period	$ 72,260	$ 93,027	$ 72,260	$ 93,027