CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Net sales	$ 2,550.3	$ 1,836.3	$ 1,475.6
Cost of sales	2,213.0	1,686.5	1,470.4
Cost of sales - inventory write-downs from restructuring	0.0	0.0	4.2
Gross profit	337.3	149.8	1.0
Selling, general and administrative expenses	204.2	174.7	180.2
Restructuring and asset impairment charges	0.0	0.0	16.6
Goodwill impairment	0.0	0.0	52.8
Operating income (loss)	133.1	(24.9)	(248.6)
Interest expense, net	54.1	44.9	32.7
Debt extinguishment losses, net	0.0	6.0	8.2
Other expense (income), net	6.5	(12.7)	8.4
Income (loss) before income taxes	72.5	(63.1)	(297.9)
Income tax expense (benefit)	16.1	(14.0)	(68.3)
Net income (loss)	$ 56.4	$ (49.1)	$ (229.6)
EARNINGS (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ 1.15	$ (1.01)	$ (4.76)
Diluted (in dollars per share)	$ 1.14	$ (1.01)	$ (4.76)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	48.8	48.5	48.3
Diluted (in shares)	49.2	48.5	48.3