Business Segment Information (Narratives) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Sales	$ 2,414.5	$ 2,581.9	$ 4,975.3	$ 5,127.4
Industrial Gases Global [Member]
Segment Reporting Information [Line Items]
Sales	67.1	68.4	126.1	135.6
Industrial Gases Global [Member] | Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Sales	$ 54.1	$ 48.4	$ 113.7	$ 89.7