Investments in Unconsolidated Affiliates - Schedule of Combined Financial Information for Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands	May 31, 2019	May 31, 2018
Equity Method Investments And Joint Ventures [Abstract]
Cash	$ 37,471	$ 52,812
Other current assets	594,959	590,578
Current assets for discontinued operations	35,793	37,640
Noncurrent assets	360,925	358,927
Total assets	1,029,148	1,039,957
Current liabilities	236,781	166,493
Current liabilities for discontinued operations	9,610	7,142
Short-term borrowings	15,162	26,599
Current maturities of long-term debt	33,003	23,243
Long-term debt	321,791	259,588
Other noncurrent liabilities	18,192	17,536
Equity	394,609	539,356
Total liabilities and equity	$ 1,029,148	$ 1,039,957