Pensions and Other Post-retirement Benefits (Details) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Components of Net Periodic Benefit Cost
Interest cost	$ 1,103,000	$ 1,116,000	$ 2,206,000	$ 2,232,000
Expected return on plan assets	(1,292,000)	(1,185,000)	(2,585,000)	(2,370,000)
Recognized net actuarial loss	862,000	750,000	1,724,000	1,500,000
Net pension expense	673,000	681,000	1,345,000	1,362,000
Employer contribution			200,000
Estimated contribution by the employer in current fiscal year to Pension Plan	1,000,000		1,000,000
Additional amount of estimated contribution by the employer in current fiscal year	$ 5,000,000		$ 5,000,000