Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Quarterly Financial Data [Abstract]
Net sales	$ 457.7	$ 456.3	$ 443.8	$ 455.6	$ 558.0	$ 570.6	$ 548.4	$ 549.8	$ 1,813.4	$ 2,226.7	$ 2,173.0
Gross profit	73.5	47.5	66.3	68.6	88.4	75.8	85.0	69.1	255.9	318.3	398.9
Operating income (loss)	29.2	(24.3)	21.8	24.8	39.5	4.8	45.0	22.1	51.6	111.5	212.0
Net income	$ 14.9	$ (23.9)	$ 11.5	$ 8.9	$ 22.5	$ (1.4)	$ 24.1	$ 13.5	$ 11.3	$ 58.7	$ 132.8
Basic (in dollars per share)	$ 0.32	$ (0.51)	$ 0.23	$ 0.18	$ 0.44	$ (0.03)	$ 0.45	$ 0.25	$ 0.23	$ 1.11	$ 2.48
Diluted (in dollars per share)	$ 0.32	$ (0.51)	$ 0.23	$ 0.18	$ 0.44	$ (0.03)	$ 0.45	$ 0.25	$ 0.23	$ 1.11	$ 2.47
Basic (in shares)	46.9	47.1	48.8	49.7	50.9	52.6	53.4	53.5	48.1	52.6	53.3
Diluted (in shares)	47.0	47.1	48.9	49.9	51.0	52.6	53.6	53.7	48.2	52.7	53.6