Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions		Mar. 31, 2020	Sep. 30, 2019
Goodwill [Line Items]
Goodwill, gross		$ 1,095.9	$ 1,162.2
Goodwill, net		785.3	797.1
Industrial Gases - Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	[1]	(310.6)	(365.1)
Goodwill, net		$ 148.5	$ 156.3

[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.