Income Taxes - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	May 31, 2022	May 31, 2021	May 31, 2020
Deferred tax assets:
Reserves related to accounts receivable	$ 10,928	$ 10,292
Inventory obsolescence	28,020	30,617
Insurance reserves	45,237	45,802
Stock-based compensation	62,522	74,898
Operating lease liabilities	43,745	44,530
Deferred compensation and other	92,250	114,553
Deferred tax assets, gross	282,702	320,692
Valuation allowance	0	(2,037)	$ (6,411)
Deferred tax assets, net	282,702	318,655
Deferred tax liabilities:
Uniform and other rental items in service	226,510	202,846
Property and equipment	171,819	167,622
Service contracts and other intangible assets	199,256	207,834
Treasury locks	31,566	0
Capitalized contract costs	81,314	79,356
Operating lease right-of-use assets	43,745	44,530
State taxes and other	2,269	3,114
Deferred tax liabilities	756,479	705,302
Net deferred tax liability	$ 473,777	$ 386,647