Pension and Other Postretirement Benefits - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	$ 0.0	$ (11.4)	$ 0.0
Plan's current allocation policy	95.00%
Percentage increase in funding level to shift assets from return seeking to liability hedging	5.00%
Return Seeking Asset
Defined Benefit Plan Disclosure [Line Items]
Plan's current allocation policy	75.00%
Liability Matching Assets
Defined Benefit Plan Disclosure [Line Items]
Plan's current allocation policy	25.00%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Mortality update		6.8
Change in discount rate	$ 225.2	7.1
Settlement charge	0.0	(11.4)	0.0
Employer contributions	3.8	23.7
Pension Benefits | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	0.7	19.9	6.5
Expected contributions for next fiscal year	0.0
Pension Benefits | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	3.1	3.8	3.3
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Mortality update	41.9	13.1
Change in plan experience		4.2
Settlement charge	0.0	0.0	0.0
Employer contributions	$ 1.6	2.7
Other Benefits | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Plan's current allocation policy	85.00%
Other Benefits | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Plan's current allocation policy	15.00%
Defined Contribution Retirement and Savings Plans
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined contribution retirement and savings plans	$ 21.0	$ 19.2	$ 25.3