Changes in Equity - Summary of Changes in Equity by Component and in Total (Detail) - USD ($) $ in Thousands		3 Months Ended					9 Months Ended
	Nov. 30, 2021	Feb. 28, 2021	Aug. 31, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	Feb. 28, 2021	Feb. 29, 2020
Balance			$ 966,433	$ 958,743	$ 907,442	$ 948,394	$ 966,433	$ 948,394
Net earnings (loss)	$ (68,512)	$ 72,682	618,738	18,888	56,922	(2,455)
Other comprehensive income (loss)	14,163	28,846	11,242	1,721	9,970	3,156	54,252	14,847
Consolidation of Samuel				24,269
Common shares issued, net of withholding tax	2,294	565	(1,150)	429	(3,811)	(3,213)
Common shares in NQ plans	292	68	90	108	239	74
Stock-based compensation	3,499	3,450	3,022	2,834	2,880	4,545
Purchases and retirement of common shares	(38,563)	(52,367)	(54,320)	(21,373)		(29,599)
Contribution to Samuel joint venture	925
Cash dividends declared	(13,527)	(13,280)	(13,595)	(13,426)	(13,446)	(13,460)
Dividends to noncontrolling interest	0	(7,250)	(560)		(1,453)
Balance	1,430,471	1,463,185	1,529,900	972,193	958,743	907,442	1,463,185	972,193
Additional Paid-in Capital
Balance			283,776	280,077	280,769	283,177	283,776	283,177
Net earnings (loss)	0	0	0	0	0	0
Other comprehensive income (loss)	0	0	0	0	0	0
Consolidation of Samuel				0
Common shares issued, net of withholding tax	2,294	565	(1,150)	429	(3,811)	(3,213)
Common shares in NQ plans	292	68	90	108	239	74
Stock-based compensation	3,499	3,450	3,022	2,834	2,880	4,545
Purchases and retirement of common shares	(4,486)	(5,315)	(7,536)	(2,812)		(3,814)
Contribution to Samuel joint venture	0
Cash dividends declared	0	0	0	0	0	0
Dividends to noncontrolling interest	0	0	0		0
Balance	279,801	278,569	278,202	280,636	280,077	280,769	278,569	280,636
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balance			(35,217)	(30,338)	(40,308)	(43,464)	(35,217)	(43,464)
Net earnings (loss)	0	0	0	0	0	0
Other comprehensive income (loss)	14,163	28,846	11,242	1,721	9,970	3,156
Consolidation of Samuel				0
Common shares issued, net of withholding tax	0	0	0	0	0	0
Common shares in NQ plans	0	0	0	0	0	0
Stock-based compensation	0	0	0	0	0	0
Purchases and retirement of common shares	0	0	0	0		0
Contribution to Samuel joint venture	0
Cash dividends declared	0	0	0	0	0	0
Dividends to noncontrolling interest	0	0	0		0
Balance	(9,812)	19,034	(23,975)	(28,617)	(30,338)	(40,308)	19,034	(28,617)
Retained Earnings
Balance			572,262	586,152	547,512	591,533	572,262	591,533
Net earnings (loss)	(74,044)	67,609	616,675	15,311	52,086	(4,776)
Other comprehensive income (loss)	0	0	0	0	0	0
Consolidation of Samuel				0
Common shares issued, net of withholding tax	0	0	0	0	0	0
Common shares in NQ plans	0	0	0	0	0	0
Stock-based compensation	0	0	0	0	0	0
Purchases and retirement of common shares	(34,077)	(47,052)	(46,784)	(18,561)		(25,785)
Contribution to Samuel joint venture	0
Cash dividends declared	(13,527)	(13,280)	(13,595)	(13,426)	(13,446)	(13,460)
Dividends to noncontrolling interest	0	0	0		0
Balance	1,006,910	1,014,187	1,128,558	569,476	586,152	547,512	1,014,187	569,476
Parent
Balance			820,821	835,891	787,973	831,246	820,821	831,246
Net earnings (loss)	(74,044)	67,609	616,675	15,311	52,086	(4,776)
Other comprehensive income (loss)	14,163	28,846	11,242	1,721	9,970	3,156
Consolidation of Samuel				0
Common shares issued, net of withholding tax	2,294	565	(1,150)	429	(3,811)	(3,213)
Common shares in NQ plans	292	68	90	108	239	74
Stock-based compensation	3,499	3,450	3,022	2,834	2,880	4,545
Purchases and retirement of common shares	(38,563)	(52,367)	(54,320)	(21,373)		(29,599)
Contribution to Samuel joint venture	0
Cash dividends declared	(13,527)	(13,280)	(13,595)	(13,426)	(13,446)	(13,460)
Dividends to noncontrolling interest	0	0	0		0
Balance	1,276,899	1,311,790	1,382,785	821,495	835,891	787,973	1,311,790	821,495
Noncontrolling Interest
Balance			145,612	122,852	119,469	117,148	145,612	117,148
Net earnings (loss)	5,532	5,073	2,063	3,577	4,836	2,321
Other comprehensive income (loss)	0	0	0	0	0	0
Consolidation of Samuel				24,269
Common shares issued, net of withholding tax	0	0	0	0	0	0
Common shares in NQ plans	0	0	0	0	0	0
Stock-based compensation	0	0	0	0	0	0
Purchases and retirement of common shares	0	0	0	0		0
Contribution to Samuel joint venture	925
Cash dividends declared	0	0	0	0	0	0
Dividends to noncontrolling interest	0	(7,250)	(560)		(1,453)
Balance	$ 153,572	$ 151,395	$ 147,115	$ 150,698	$ 122,852	$ 119,469	$ 151,395	$ 150,698