Summarized Financial Information of Equity Affiliates (Narratives) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Obligation for future contribution to equity affiliate	$ 94.4	$ 67.5
Investment in net assets of and advances to equity affiliates	1,283.6	1,249.8
Goodwill associated with affiliate companies accounted for by equity method.	109.5	112.0
Dividends received from equity affiliates	95.9	50.5	$ 74.0
Foreign Affiliate [Member]
Schedule of Equity Method Investments [Line Items]
Investment in net assets of and advances to equity affiliates	$ 1,281.5	1,246.9
Jazan Gas Projects Company [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%
Obligation for future contribution to equity affiliate	$ 94.4	67.5
Noncash transaction, increase to investment	26.9	$ 67.5
Total expected investment	$ 100.0

Total expected investment in equity affiliate

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Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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The amount of investments that an Entity acquires in a noncash (or part noncash) acquisition. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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