Interim Pension and Other Postretirement Benefits (Details) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Supplemental Executive Benefit Plans [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount Rate	4.21%	5.05%	4.21%	5.05%
Rate of compensation increase	3.50%	3.50%	3.50%	3.50%
Pension Benefits [Member]
Components of net periodic pension cost [Abstract]
Service Cost	$ 5,194,000	$ 4,297,000	$ 15,599,000	$ 12,893,000
Interest Cost	6,019,000	6,677,000	18,067,000	20,032,000
Expected return on assets	(5,739,000)	(5,368,000)	(17,216,000)	(16,105,000)
Amortization of transition (asset)/obligation	0	0	0	0
Amortization of prior service (credit)/cost	(35,000)	(35,000)	(106,000)	(106,000)
Amortization of actuarial (gain) loss	5,432,000	4,142,000	16,555,000	12,427,000
Curtailment	3,161,000	0	3,161,000	0
Net periodic pension cost	14,032,000	9,713,000	36,060,000	29,141,000
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount Rate	4.04%	5.05%	4.04%	5.05%
Rate of compensation increase	3.50%	3.50%	3.50%	3.50%
Expected return on plan assets	7.75%	7.75%	7.75%	7.75%
Current Year Benefit Plan Contributions [Abstract]
Contributions Actual			21,000,000
Contributions Estimate			12,000,000
Effect On Net Periodic Cost Due To Discount Rate Change	(100,000)		100,000
Other Benefits [Member]
Components of net periodic pension cost [Abstract]
Service Cost	4,700,000	4,089,000	14,100,000	12,265,000
Interest Cost	3,241,000	3,465,000	9,723,000	10,396,000
Expected return on assets	(997,000)	(651,000)	(2,991,000)	(1,955,000)
Amortization of transition (asset)/obligation	271,000	377,000	811,000	1,133,000
Amortization of prior service (credit)/cost	(363,000)	(362,000)	(1,088,000)	(1,087,000)
Amortization of actuarial (gain) loss	1,049,000	662,000	3,147,000	1,986,000
Curtailment	0	0	0	0
Net periodic pension cost	7,901,000	7,580,000	23,702,000	22,738,000
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount Rate	4.04%	5.05%	4.04%	5.05%
Expected return on plan assets	4.70%	4.70%	4.70%	4.70%
Current Year Benefit Plan Contributions [Abstract]
Contributions Actual			19,500,000
Contributions Estimate Minimum			5,000,000
Contributions Estimate Maximum			$ 10,000,000