Taxes - Schedule for components for deferred income taxes (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Deferred tax assets:
Tax uniform capitalization	$ 9.8	$ 8.6
Prepublication expenses	0.6	0.6
Inventory reserves	21.3	19.3
Allowance for credit losses	4.0	2.8
Deferred revenue	2.5	13.5
Stock Based Compensation	8.0	9.1
Other reserves	8.4	10.8
Postretirement, post employment and pension obligations	2.3	3.1
Tax carryforwards	35.2	39.7
Lease liabilities	22.8	23.7
Other	15.7	14.1
Gross deferred tax assets	130.6	145.3
Valuation allowance	(23.1)	(23.1)
Total deferred tax assets	107.5	122.2
Deferred tax liabilities:
Depreciation and amortization	(66.4)	(74.3)
Lease Right of Use Assets	(20.7)	(20.2)
Other	(2.5)	(2.3)
Total deferred tax liability	(89.6)	(96.8)
Total net deferred tax assets	$ 17.9	$ 25.4