Goodwill (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Jun. 30, 2017	Sep. 30, 2017
Goodwill [Line Items]
Goodwill impairment charge		$ 145.3
Industrial Gases - Americas
Goodwill [Line Items]
Goodwill impairment charge	$ 145.3	$ 145.3

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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