Changes Recognized in Other Comprehensive Income, Postretirement Benefits (Detail) - Postretirement Benefits - USD ($) $ in Thousands	12 Months Ended
	May 31, 2021	May 31, 2020
Domestic
Changes in plan assets and benefit obligations recognized in other comprehensive income:
Net loss (gain) arising during the year	$ 152	$ 702
Amounts recognized as a component of net periodic benefit cost:
Amortization or curtailment recognition of prior service credit	167	219
Amortization or settlement recognition of net gain (loss)	(41)	66
Total recognized in other comprehensive loss (income)	278	987
Non-U.S. Plans
Changes in plan assets and benefit obligations recognized in other comprehensive income:
Net loss (gain) arising during the year	(6,415)	(683)
Effect of exchange rates on amounts included in AOCI	1,574	(266)
Amounts recognized as a component of net periodic benefit cost:
Amortization or settlement recognition of net gain (loss)	(590)	(611)
Total recognized in other comprehensive loss (income)	$ (5,431)	$ (1,560)