v3.26.1
Pension and Other Postretirement Benefits - Summary of Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($)
$ in Millions
12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Pension Benefits    
Amounts recognized in accumulated other comprehensive loss:    
Net actuarial loss (gain) $ 151.8 $ 198.9
Prior service cost 0.6 2.1
Total 152.4 201.0
Other changes in plan assets and benefit obligations recognized in other comprehensive income consist of:    
Net actuarial gain (40.2) (9.2)
Amortization of net (loss) gain (6.6) (7.3)
Amortization of prior service cost (1.5) (2.1)
Settlement charge (0.3) 0.0
Total, before tax effect (48.6) (18.6)
Additional information:    
Accumulated benefit obligation for all pension plans 636.3 674.2
Other Postretirement Plans    
Amounts recognized in accumulated other comprehensive loss:    
Net actuarial loss (gain) (81.4) (66.8)
Prior service cost 0.0 0.3
Total (81.4) (66.5)
Other changes in plan assets and benefit obligations recognized in other comprehensive income consist of:    
Net actuarial gain (20.6) (8.1)
Amortization of net (loss) gain 5.9 5.6
Amortization of prior service cost (0.2) (1.2)
Settlement charge 0.0 0.0
Total, before tax effect $ (14.9) $ (3.7)