Business Segment Information (Narratives) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Sales	$ 2,271.2	$ 2,414.5	$ 4,627.0	$ 4,975.3
Industrial Gases - Global [Member]
Segment Reporting Information [Line Items]
Sales	86.6	67.1	190.9	126.1
Industrial Gases - Global [Member] \| Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Sales	$ 56.6	$ 54.1	$ 111.2	$ 113.7

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration