CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 479.8	$ 389.0
Cost of sales	394.2	343.0
Gross profit	85.6	46.0
Selling, general and administrative expenses	43.9	44.6
Operating income	41.7	1.4
Interest expense	(7.2)	(7.3)
Other income, net	0.7	0.6
Income (loss) before income taxes	35.2	(5.3)
Income tax expense	11.8	0.9
Net income (loss)	$ 23.4	$ (6.2)
EARNINGS (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ 0.49	$ (0.13)
Diluted (in dollars per share)	$ 0.49	$ (0.13)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	47.1	46.9
Diluted (in shares)	47.3	46.9
Cash dividends per common share (in dollars per share)	$ 0.18	$ 0.18