Accumulated Other Comprehensive Income (Loss) - Reclassification out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Less: Tax effect	$ (25.5)	$ (20.7)	$ (13.0)	$ (11.8)
Net income (loss) attributable to Scholastic Corporation	(75.3)	(68.3)	(29.8)	(44.1)
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)	0.1	0.2	0.2	0.4
Amortization of prior service (credit) loss	(0.2)	(0.2)	(0.4)	(0.4)
Less: Tax effect	0.0	0.0	0.1	0.1
Net income (loss) attributable to Scholastic Corporation	$ (0.1)	$ 0.0	$ (0.1)	$ 0.1