Retirement and Post-Retirement Employee Benefit Plans Fair Value Disclosures (Details) (USD $) In Thousands	Sep. 30, 2011	Sep. 30, 2010
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	$ 94,336	$ 116,315
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	27,236	32,601
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	53,309	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	4,946	5,548
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Real Estate Investment [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	9,383	10,013
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	48,920
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	18,907	16,296
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	33,636	33,987
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	37,806	37,691
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Real Estate Investment [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Pension Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Real Estate Investment [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	200	200
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	94,336	116,315
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	9,383	10,013
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	27,236	32,601
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	53,309	48,920
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	23,853	21,844
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	33,636	33,987
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	37,806	37,691
Pension Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Real Estate Investment [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	200	200
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	51,358	51,726
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 1 [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	1,707	1,307
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 2 [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Level 3 [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Equity Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Money Market Funds [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	1,707	1,307
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Registered Investment Companies [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	51,358	51,726
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Common Collective Trusts [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | US Treasury And Government [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Corporate Debt Securities [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	0	0
Other Postretirement Benefit Plans Defined Benefit [Member] | Fair Value Inputs Total [Member] | Limited Partnership Interest [Member]
Schedule of Total Investments at Fair Value [Line Items]
Total investments at fair value	$ 0	$ 0