CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
NET SALES	$ 548.4	$ 503.5	$ 1,098.2	$ 1,002.1
Cost of sales	463.4	408.1	944.1	803.3
Gross profit	85.0	95.4	154.1	198.8
Selling, general and administrative expenses	40.0	47.9	86.9	95.5
Operating income	45.0	47.5	67.2	103.3
Interest expense, net	(6.8)	(3.7)	(13.8)	(8.2)
Other income, net	0	0.6	4.8	0.8
Income before income taxes	38.2	44.4	58.2	95.9
Income tax expense	14.1	14.9	20.6	31.8
Net income	$ 24.1	$ 29.5	$ 37.6	$ 64.1
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.45	$ 0.55	$ 0.70	$ 1.20
Diluted (in dollars per share)	$ 0.45	$ 0.55	$ 0.70	$ 1.19
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	53.4	53.2	53.5	53.2
Diluted (in shares)	53.6	53.6	53.7	53.5
Cash dividends per common share (in dollars per share)	$ 0.18	$ 0.18	$ 0.36	$ 0.36