Accumulated Other Comprehensive Income (Loss) - Reclassification out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Less: Tax effect	$ 4.7	$ 8.0	$ (7.1)	$ 7.6
Net income (loss) attributable to Scholastic Corporation	15.3	13.9	(28.8)	18.6
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	0.1	0.6	0.4
Amortization of prior service (credit) loss	(0.2)	(0.2)	(0.6)	(0.4)
Less: Tax effect	0.0	0.1	0.1	0.2
Net income (loss) attributable to Scholastic Corporation	$ 0.0	$ 0.0	$ 0.1	$ 0.2