Changes in Equity - Summary of Changes in Equity by Component and in Total (Detail) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2020	Aug. 31, 2019
Balance	$ 966,433	$ 948,394
Net earnings (loss)	618,738	(2,456)
Other comprehensive income	11,242	3,156
Common shares issued, net of withholding tax	(1,150)	(3,213)
Common shares in NQ plans	90	74
Stock-based compensation	3,022	4,545
Purchases and retirement of common shares	(54,320)	(29,599)
Cash dividends declared	(13,595)	(13,460)
Dividends to noncontrolling interest	(560)
Balance	1,529,900	907,441
Additional Paid-in Capital
Balance	283,776	283,177
Net earnings (loss)	0	0
Other comprehensive income	0	0
Common shares issued, net of withholding tax	(1,150)	(3,213)
Common shares in NQ plans	90	74
Stock-based compensation	3,022	4,545
Purchases and retirement of common shares	(7,536)	(3,814)
Cash dividends declared	0	0
Dividends to noncontrolling interest	0
Balance	278,202	280,769
Accumulated Other Comprehensive Loss, Net of Tax
Balance	(35,217)	(43,464)
Net earnings (loss)	0	0
Other comprehensive income	11,242	3,156
Common shares issued, net of withholding tax	0	0
Common shares in NQ plans	0	0
Stock-based compensation	0	0
Purchases and retirement of common shares	0	0
Cash dividends declared	0	0
Dividends to noncontrolling interest	0
Balance	(23,975)	(40,308)
Retained Earnings
Balance	572,262	591,533
Net earnings (loss)	616,675	(4,776)
Other comprehensive income	0	0
Common shares issued, net of withholding tax	0	0
Common shares in NQ plans	0	0
Stock-based compensation	0	0
Purchases and retirement of common shares	(46,784)	(25,785)
Cash dividends declared	(13,595)	(13,460)
Dividends to noncontrolling interest	0
Balance	1,128,558	547,512
Parent
Balance	820,821	831,246
Net earnings (loss)	616,675	(4,776)
Other comprehensive income	11,242	3,156
Common shares issued, net of withholding tax	(1,150)	(3,213)
Common shares in NQ plans	90	74
Stock-based compensation	3,022	4,545
Purchases and retirement of common shares	(54,320)	(29,599)
Cash dividends declared	(13,595)	(13,460)
Dividends to noncontrolling interest	0
Balance	1,382,785	787,973
Noncontrolling Interest
Balance	145,612	117,148
Net earnings (loss)	2,063	2,320
Other comprehensive income	0	0
Common shares issued, net of withholding tax	0	0
Common shares in NQ plans	0	0
Stock-based compensation	0	0
Purchases and retirement of common shares	0	0
Cash dividends declared	0	0
Dividends to noncontrolling interest	(560)
Balance	$ 147,115	$ 119,468