Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Goodwill [Line Items]
Goodwill, gross		$ 1,194.7	$ 1,138.7	$ 1,103.7
Goodwill, net		788.9	721.5	845.1
Industrial Gases - Americas
Goodwill [Line Items]
Accumulated impairment losses	[1]	(405.8)	(417.2)	(258.6)
Goodwill, net		$ 162.1	$ 163.7	$ 309.1

[1] Accumulated impairment losses include the impacts of currency translation. These losses are attributable to our Latin America reporting unit (LASA) within the Industrial Gases – Americas segment.