Fair Value Measurements (Fair Value Measurements Using Unobservable Inputs (Level 3)) (Details) - Derivative Financial Instruments [Member] - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2015		Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Roll Forward]
Beginning Balance	[1]	$ 1,791		$ 1,368
Total Gains/Losses, Realized and Included in Earnings	[1]	(2,002)	[2]	(3,855)	[3]
Total Gains/Losses Unrealized and Included in Other Comprehensive Income (Loss)	[1]	211		7,824
Transfer In/Out of Level 3	[1]	0		0
Ending Balance	[1]	$ 0		$ 5,337

[1] Derivative Financial Instruments are shown on a net basis.

[2] Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the three months ended December 31, 2015.

[3] Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the three months ended December 31, 2014.