Goodwill (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Sep. 30, 2014		Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment charge	$ 305.2		$ 305.2		$ 0
Goodwill accumulated impairment losses	$ 284.8	[1]	$ 284.8	[1]	$ 0	[1]	$ 0	[1]

[1] Amount is attributable to the Merchant Gases segment and includes currency translation of $20.4.