Financial Instruments Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Other Comprehensive Income [Abstract]
Interest rate agreements fair value		$ 74,560	$ (99,029)
Forward commodity contracts fair value		9,847	(11,662)
Interest rate agreements		662	347
Forward commodity contracts		(4,865)	32,117
Total other comprehensive income (loss) from hedging, net of tax	[1]	80,204	(78,227)
Interest Rate Contract [Member]
Other Comprehensive Income [Abstract]
Total other comprehensive income (loss) from hedging, net of tax		75,222	(98,682)	$ (70,461)
Expected Earnings [Line Items]
FY2018		(1,509)
FY2019		(1,533)
FY2020		(1,557)
FY2021		(1,557)
FY2022		(1,557)
Thereafter		(33,420)
Cash Flow Hedge Gain (Loss) To Be Reclassiflied, Total	[2]	(41,133)
Commodity Contract [Member]
Other Comprehensive Income [Abstract]
Total other comprehensive income (loss) from hedging, net of tax		$ 4,982	$ 20,455	$ (23,763)

[1] Utilizing an income tax rate ranging from approximately 37 percent to 39 percent based on the effective rates in each taxing jurisdiction.

[2] Utilizing an income tax rate of 37 percent.