Retirement Plan And Other Post-Retirement Benefits (Schedule Of Effect Of Significant Unobservable Inputs Changes In Plan Assets) (Details) (USD $) In Thousands	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2009	Sep. 30, 2008
Deferred Tax Asset [Member] | Other Post-Retirement Benefit Assets [Member]
Fair Value of Investments	$ 4,242		$ 2,230
Accrued Income Receivable [Member] | Retirement Plan Assets [Member]
Fair Value of Investments	467		699
Accrued Income Receivable [Member] | Other Post-Retirement Benefit Assets [Member]
Fair Value of Investments			640
Accrued Administrative Costs [Member] | Retirement Plan Assets [Member]
Fair Value of Investments	(605)		(604)
Accrued Administrative Costs [Member] | Other Post-Retirement Benefit Assets [Member]
Fair Value of Investments	(221)		(196)
Claims Incurred But Not Reported [Member] | Other Post-Retirement Benefit Assets [Member]
Fair Value of Investments	(1,854)		(1,736)
Prepaid Federal Taxes [Member] | Other Post-Retirement Benefit Assets [Member]
Fair Value of Investments	3,120		2,866
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member]
Fair Value of Investments	305,231		212,840
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | 401(h) Investments [Member]
Fair Value of Investments	(17,744)		(11,647)
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | Domestic Equities [Member]
Fair Value of Investments	215,524	[1]	172,841	[1]
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | International Equities [Member]
Fair Value of Investments	11,163	[2]	21,051	[2]
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | Domestic Fixed Income [Member]
Fair Value of Investments	77,657	[3]	18,948	[3]
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | International Fixed Income [Member]
Fair Value of Investments	887	[4]	0	[4]
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | Hedge Funds Investments [Member]
Fair Value of Investments	0
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | Limited Partnership [Member]
Fair Value of Investments			0
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | Cash And Cash Equivalents [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 1 [Member] | Retirement Plan Investments [Member] | Real Estate [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | 401(h) Investments [Member]
Fair Value of Investments	17,744		11,647
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Cash Held In Collective Trust Funds [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds International [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds Domestic [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Exchange Traded Funds Fixed Income [Member]
Fair Value of Investments	91,214
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Real Estate [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Total Investments Including 401H Investments [Member]
Fair Value of Investments	108,958		11,647
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Assets [Member] | Total VEBA Trust Investments [Member]
Fair Value of Investments	91,214		0
Fair Value, Inputs, Level 1 [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]
Fair Value of Investments	287,487		201,193
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member]
Fair Value of Investments	288,063		412,467
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | 401(h) Investments [Member]
Fair Value of Investments	(16,773)		(22,569)
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | Domestic Equities [Member]
Fair Value of Investments	97,669	[1]	168,735	[1]
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | International Equities [Member]
Fair Value of Investments	68,569	[2]	78,536	[2]
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | Domestic Fixed Income [Member]
Fair Value of Investments	68,930	[3]	80,515	[3]
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | International Fixed Income [Member]
Fair Value of Investments	42,266	[4]	73,535	[4]
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | Hedge Funds Investments [Member]
Fair Value of Investments	0
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | Limited Partnership [Member]
Fair Value of Investments			0
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | Cash And Cash Equivalents [Member]
Fair Value of Investments	10,629		11,146
Fair Value, Inputs, Level 2 [Member] | Retirement Plan Investments [Member] | Real Estate [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | 401(h) Investments [Member]
Fair Value of Investments	16,773		22,569
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Cash Held In Collective Trust Funds [Member]
Fair Value of Investments	12,890		7,622
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds International [Member]
Fair Value of Investments	55,411		85,799
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds Domestic [Member]
Fair Value of Investments	148,451		217,637
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Exchange Traded Funds Fixed Income [Member]
Fair Value of Investments	0
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Real Estate [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Total Investments Including 401H Investments [Member]
Fair Value of Investments	233,525		333,627
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Assets [Member] | Total VEBA Trust Investments [Member]
Fair Value of Investments	216,752		311,058
Fair Value, Inputs, Level 2 [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]
Fair Value of Investments	271,290		389,898
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member]
Fair Value of Investments	45,739		6,730
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | 401(h) Investments [Member]
Fair Value of Investments	(2,659)		(367)
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | Domestic Equities [Member]
Fair Value of Investments	0	[1]	337	[1]
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | International Equities [Member]
Fair Value of Investments	0	[2]	0	[2]
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | Domestic Fixed Income [Member]
Fair Value of Investments	0	[3]	0	[3]
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | International Fixed Income [Member]
Fair Value of Investments	0	[4]	0	[4]
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | Hedge Funds Investments [Member]
Fair Value of Investments	39,296
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | Limited Partnership [Member]
Fair Value of Investments			245
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | Cash And Cash Equivalents [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 3 [Member] | Retirement Plan Investments [Member] | Real Estate [Member]
Fair Value of Investments	6,443		6,148
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | 401(h) Investments [Member]
Fair Value of Investments	2,659		367
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Cash Held In Collective Trust Funds [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds International [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds Domestic [Member]
Fair Value of Investments	0		0
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Exchange Traded Funds Fixed Income [Member]
Fair Value of Investments	0
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Real Estate [Member]
Fair Value of Investments	1,561		3,824
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Total Investments Including 401H Investments [Member]
Fair Value of Investments	4,220		4,191
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Assets [Member] | Total VEBA Trust Investments [Member]
Fair Value of Investments	1,561		3,824
Fair Value, Inputs, Level 3 [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]
Fair Value of Investments	43,080		6,363
Other Post-Retirement Benefit Plans, Defined Benefit [Member]
Fair Value of Investments	351,990		353,269		319,022	377,640
Retirement Plan [Member]
Fair Value of Investments	601,719		597,549		563,881	695,089
Retirement Plan Investments [Member]
Fair Value of Investments	639,033		632,037
Retirement Plan Investments [Member] | 401(h) Investments [Member]
Fair Value of Investments	(37,176)		(34,583)
Retirement Plan Investments [Member] | Domestic Equities [Member]
Fair Value of Investments	313,193	[1]	341,913	[1]
Retirement Plan Investments [Member] | International Equities [Member]
Fair Value of Investments	79,732	[2]	99,587	[2]
Retirement Plan Investments [Member] | Domestic Fixed Income [Member]
Fair Value of Investments	146,587	[3]	99,463	[3]
Retirement Plan Investments [Member] | International Fixed Income [Member]
Fair Value of Investments	43,153	[4]	73,535	[4]
Retirement Plan Investments [Member] | Hedge Funds Investments [Member]
Fair Value of Investments	39,296
Retirement Plan Investments [Member] | Limited Partnership [Member]
Fair Value of Investments			245
Retirement Plan Investments [Member] | Cash And Cash Equivalents [Member]
Fair Value of Investments	10,629		11,146
Retirement Plan Investments [Member] | Real Estate [Member]
Fair Value of Investments	6,443		6,148
Retirement Plan Assets [Member]
Fair Value of Investments	601,719		597,549
Other Post-Retirement Benefit Assets [Member]
Fair Value of Investments	351,990		353,269
Other Post-Retirement Benefit Assets [Member] | 401(h) Investments [Member]
Fair Value of Investments	37,176		34,583
Other Post-Retirement Benefit Assets [Member] | Cash Held In Collective Trust Funds [Member]
Fair Value of Investments	12,890		7,622
Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds International [Member]
Fair Value of Investments	55,411		85,799
Other Post-Retirement Benefit Assets [Member] | Collective Trust Funds Domestic [Member]
Fair Value of Investments	148,451		217,637
Other Post-Retirement Benefit Assets [Member] | Exchange Traded Funds Fixed Income [Member]
Fair Value of Investments	91,214
Other Post-Retirement Benefit Assets [Member] | Real Estate [Member]
Fair Value of Investments	1,561		3,824
Other Post-Retirement Benefit Assets [Member] | Total Investments Including 401H Investments [Member]
Fair Value of Investments	346,703		349,465
Other Post-Retirement Benefit Assets [Member] | Total VEBA Trust Investments [Member]
Fair Value of Investments	309,527		314,882
Total Retirement Plan Investments Excluding 401 H Investments [Member]
Fair Value of Investments	$ 601,857		$ 597,454

[1] Domestic Equities include collective trust funds, common stock, convertible securities and preferred stock.

[2] International Equities include collective trust funds and common stock.

[3] Domestic Fixed Income securities include collective trust funds, corporate bonds, and exchange traded funds.

[4] International Fixed Income securities are comprised of collective trust funds.