Summary of Significant Accounting Policies (Details 6) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Comprehensive Income (Loss)
Net income	$ 50,182	$ 31,128	$ 8,875
Other comprehensive income (loss), Pre-tax
Pension and postretirement	(26,537)	(28,326)	(20,935)
Foreign currency translation adjustment	698	645	(539)
Other comprehensive income (loss)	(25,839)	(27,681)	(21,474)
Other comprehensive income (loss), Tax
Pension and postretirement	9,796	10,670	7,893
Other comprehensive income (loss)	9,796	10,670	7,893
Other comprehensive income (loss), Net
Pension and postretirement	(16,741)	(17,656)	(13,042)
Foreign currency translation adjustment	698	645	(539)
Other comprehensive loss	(16,043)	(17,011)	(13,581)
Comprehensive income (loss)	$ 34,139	$ 14,117	$ (4,706)