Employee Pension Plans - Other Changes in Plan Assets And Benefit Obligations Recognized in OCI (Detail) - USD ($) $ in Thousands	12 Months Ended
May 31, 2021	May 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Net gain (loss)	$ 7,097	$ (7,596)
Amortization of net loss	775	553
Total recognized in other comprehensive income (loss)	7,872	(7,043)
Total recognized in net periodic benefit cost and other comprehensive income (loss)	$ (7,898)	$ 7,095

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent.

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