Retirement Benefit Plans (Details 5) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Amounts recognized in the consolidated balance sheets are:
Asset Amount	$ 18,949	$ 16,642	$ 16,653
Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	139	177
Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	16,717	14,372
Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	2,093	2,093	1,911
Large value [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	288	204
Large value [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Large value [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	288	204
Large value [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Large blend [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	8,592	6,945
Large blend [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Large blend [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	8,592	6,945
Large blend [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Large growth [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	640	832
Large growth [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Large growth [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	640	832
Large growth [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Mid blend [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	19	43
Mid blend [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Mid blend [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	19	43
Mid blend [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Small blend [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	4	34
Small blend [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Small blend [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	4	34
Small blend [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Foreign large blend [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	1,295	1,048
Foreign large blend [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Foreign large blend [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	1,295	1,048
Foreign large blend [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Diversified emerging markets [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	70	109
Diversified emerging markets [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Diversified emerging markets [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	70	109
Diversified emerging markets [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Inflation protected bond [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	952	489
Inflation protected bond [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Inflation protected bond [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	952	489
Inflation protected bond [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Intermediate term bond [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	6,412	6,176
Intermediate term bond [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Intermediate term bond [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	4,319	4,083
Intermediate term bond [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	2,093	2,093
High inflation bond [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	299	328
High inflation bond [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
High inflation bond [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	299	328
High inflation bond [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Emerging markets bonds [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	239	257
Emerging markets bonds [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Emerging markets bonds [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	239	257
Emerging markets bonds [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Short-term bonds [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	139	177
Short-term bonds [Member] | Level 1 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	139	177
Short-term bonds [Member] | Level 2 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	0	0
Short-term bonds [Member] | Level 3 [Member]
Amounts recognized in the consolidated balance sheets are:
Asset Amount	$ 0	$ 0