Disclosures About Derivative Instruments and Hedging Activities - Effects of Derivatives on Statements of Income and AOCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Derivatives Not Designated as Hedging Instruments | Commodity contracts | Operating expenses/other income, net
Derivative Instruments, Gain (Loss)
Gain (Loss) recognized in income	$ (18)	$ 107	$ 79	$ 105
Cash Flow Hedges | Interest rate contracts | Interest expense, net
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in AOCI	0	6,116	0	10,452
Gain (loss) reclassified from AOCI into income	$ (670)	$ (202)	$ 1,339	$ (405)