Accumulated Other Comprehensive Income (Loss) - Reclassification out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Less: Tax effect	$ 6.9	$ 4.7	$ (6.1)	$ (7.1)
Net income (loss) attributable to Scholastic Corporation	19.2	15.3	(10.6)	(28.8)
Amount reclassified from Accumulated other comprehensive income (loss) | Retirement benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of unrecognized gain (loss)	0.2	0.2	0.4	0.6
Amortization of prior service (credit) loss	(0.3)	(0.2)	(0.7)	(0.6)
Less: Tax effect	0.1	0.0	0.2	0.1
Net income (loss) attributable to Scholastic Corporation	$ 0.0	$ 0.0	$ (0.1)	$ 0.1