Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income tax (benefit) expense	$ (16.7)		$ 10.0	$ (46.4)	$ 34.6
Income tax expense as a percent of pre-tax income (loss)	29.20%		20.00%	21.20%	22.40%
Tax benefit related to pension settlement charges	$ 2.2			$ 2.2
Tax benefit related to the impact of restructuring charges	1.8			4.2
Tax benefit related to changes in prior year tax positions	$ 0.8		$ 1.6	$ 0.8	$ 1.6
Effective income tax rate reconciliation, excluding pension settlement charges, non-deductible expense, impairment losses and prior year income taxes, percent	29.30%			28.20%
Tax benefit associated with debt prepayment costs				$ 2.0
Tax expense (benefit) attributable to employee share-based compensation				1.2	(0.5)
Goodwill impairment		$ 0.0	$ 0.0	52.8	$ 0.0
Operating loss carryforward, income tax expense (benefit), CARES act				$ 7.0