Investments in Unconsolidated Affiliates - Schedule of Combined Financial Information for Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019	May 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Cash	$ 33,002		$ 33,002		$ 37,471
Other current assets	611,784		611,784		594,959
Current assets for discontinued operations					35,793
Noncurrent assets	379,984		379,984		360,925
Total assets	1,024,770		1,024,770		1,029,148
Current liabilities	163,758		163,758		236,781
Current liabilities for discontinued operations					9,610
Short-term borrowings	3,437		3,437		15,162
Current maturities of long-term debt	2,374		2,374		33,003
Long-term debt	352,827		352,827		321,791
Other noncurrent liabilities	47,107		47,107		18,192
Equity	455,267		455,267		394,609
Total liabilities and equity	1,024,770		1,024,770		$ 1,029,148
Net sales	477,494	$ 440,186	1,400,987	$ 1,385,399
Gross margin	100,070	74,783	293,601	247,852
Operating income	52,429	45,387	181,067	158,475
Depreciation and amortization	8,482	6,138	23,109	19,368
Interest expense	3,667	3,529	10,173	9,836
Income tax expense (benefit)	(614)	1,001	1,239	8,433
Net earnings from continuing operations	54,806	40,196	169,430	141,613
Net earnings from discontinued operations		1,001	49,770	4,713
Net earnings	$ 54,806	$ 41,197	$ 219,200	$ 146,326