Investments in Unconsolidated Affiliates - Schedule of Combined Financial Information for Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018	May 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Cash	$ 31,641		$ 31,641		$ 37,471
Other current assets	633,772		633,772		594,959
Current assets for discontinued operations					35,793
Noncurrent assets	390,433		390,433		360,925
Total assets	1,055,846		1,055,846		1,029,148
Current liabilities	202,450		202,450		236,781
Current liabilities for discontinued operations					9,610
Short-term borrowings	1,965		1,965		15,162
Current maturities of long-term debt	2,582		2,582		33,003
Long-term debt	346,223		346,223		321,791
Other noncurrent liabilities	42,144		42,144		18,192
Equity	460,482		460,482		394,609
Total liabilities and equity	1,055,846		1,055,846		$ 1,029,148
Net sales	458,859	$ 480,716	946,134	$ 979,261
Gross margin	97,329	75,515	198,944	179,327
Operating income	63,452	44,592	132,857	116,968
Depreciation and amortization	7,538	6,581	14,627	13,058
Interest expense	3,139	3,382	6,506	6,307
Income tax expense	1,576	3,568	2,578	8,093
Net earnings from continuing operations	104,431	36,523	165,572	101,417
Net earnings (loss) from discontinued operations	(3,990)	2,028	(1,178)	3,712
Net earnings	$ 100,441	$ 38,551	$ 164,394	$ 105,129