CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Income Statement [Abstract]
Net sales	$ 727.0	$ 684.9	$ 2,121.5	$ 1,961.1
Cost of sales	526.2	537.9	1,566.9	1,567.4
Gross profit	200.8	147.0	554.6	393.7
Selling, general and administrative expenses	63.0	57.0	180.6	164.8
Restructuring and asset impairment charges	0.0	0.0	3.6	0.0
Goodwill impairment	0.0	14.1	0.0	14.1
Operating income	137.8	75.9	370.4	214.8
Interest expense, net	12.0	12.9	36.6	38.6
Other expense, net	3.8	52.9	5.6	58.5
Income before income taxes	122.0	10.1	328.2	117.7
Income tax expense	26.6	3.8	63.9	24.8
Net income	$ 95.4	$ 6.3	$ 264.3	$ 92.9
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 1.90	$ 0.12	$ 5.27	$ 1.87
Diluted (in dollars per share)	$ 1.88	$ 0.12	$ 5.21	$ 1.85
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	50.2	49.7	50.2	49.5
Diluted (in shares)	50.7	50.3	50.7	50.1