CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 2,181,100,000	$ 2,380,200,000	$ 2,157,700,000
Cost of sales	1,822,400,000	1,935,400,000	1,775,400,000
Cost of sales - inventory write-downs from restructuring	29,300,000	0	0
Gross profit	329,400,000	444,800,000	382,300,000
Selling, general and administrative expenses	201,000,000.0	203,400,000	193,000,000.0
Restructuring and asset impairment charges	68,500,000	0	0
Goodwill impairment	34,600,000	0	0
Operating income	25,300,000	241,400,000	189,300,000
Interest expense	(19,800,000)	(26,000,000.0)	(28,300,000)
Other income (expense), net	600,000	600,000	(800,000)
Income before income taxes	6,100,000	216,000,000.0	160,200,000
Income tax expense (benefit)	4,600,000	49,000,000.0	(28,300,000)
Net income	$ 1,500,000	$ 167,000,000.0	$ 188,500,000
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.02	$ 3.46	$ 3.96
Diluted (in dollars per share)	$ 0.02	$ 3.43	$ 3.92
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	48.1	47.7	47.2
Diluted (in shares)	48.2	48.1	47.6