Supplemental Data (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Cost Data:
Repairs and maintenance costs	$ 68.9	$ 117.4	$ 120.4
Noncash investing and financing activities:
Noncash purchases of property, plant, equipment and software	7.3	11.6	16.1
Cash paid during the year for:
Interest payments, net	28.2	27.0	27.6
Income tax payments, net	$ 2.1	$ 29.8	$ 27.5