Pension and Other Postretirement Benefits - Schedule of Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Pension Benefits
Amounts recognized in accumulated other comprehensive loss:
Net actuarial loss (gain)	$ 260.3	$ 282.0
Prior service cost (credit)	5.8	7.9
Total	266.1	289.9
Other changes in plan assets and benefit obligations recognized in other comprehensive income consist of:
Net actuarial gain	(12.5)	(7.5)
Amortization of net (loss) gain	(9.5)	(8.4)
Amortization of prior service (cost) benefit	(2.1)	(2.1)
Total, before tax effect	(24.1)	(18.0)
Additional information:
Accumulated benefit obligation for all pension plans	843.8	956.4
Other Benefits
Amounts recognized in accumulated other comprehensive loss:
Net actuarial loss (gain)	(39.7)	(10.3)
Prior service cost (credit)	(2.4)	(6.2)
Total	(42.1)	(16.5)
Other changes in plan assets and benefit obligations recognized in other comprehensive income consist of:
Net actuarial gain	(31.2)	(21.3)
Amortization of net (loss) gain	1.8	0.8
Amortization of prior service (cost) benefit	3.9	3.9
Total, before tax effect	$ (25.5)	$ (16.6)