Business Separation (Narrative)(Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2015		Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014	[1]	Sep. 30, 2015	[1]	Sep. 30, 2014	Sep. 30, 2013
Restructuring and Related Activities [Abstract]
Business separation costs	$ 7.5	[1]	$ 0.0		$ 0.0		$ 0.0		$ 7.5		$ 0.0	$ 0.0
Business separation costs per share	$ 0.03

[1] For additional information, see Note 3, Materials Technologies Separation.