Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions		Dec. 31, 2018	Sep. 30, 2018
Goodwill [Line Items]
Goodwill, gross		$ 1,164.1	$ 1,194.7
Goodwill, net		780.4	788.9
Industrial Gases - Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	[1]	(383.7)	(405.8)
Goodwill, net		$ 158.9	$ 162.1

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