Comprehensive Income (Loss) and Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income (loss) at the beginning of the period	$ (99,091)	$ (83,048)
Other comprehensive income (loss) before classifications	36,491	(20,494)
Amounts reclassified from accumulated other comprehensive income (loss)	5,801	4,451
Net current-period other comprehensive income (loss)	42,292	(16,043)
Accumulated other comprehensive income (loss) at the end of the period	(56,799)	(99,091)
Defined Benefit Plans | Pension Plan
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income (loss) at the beginning of the period	(75,263)	(67,822)
Other comprehensive income (loss) before classifications	25,317	(13,836)
Amounts reclassified from accumulated other comprehensive income (loss)	7,148	6,395
Net current-period other comprehensive income (loss)	32,465	(7,441)
Accumulated other comprehensive income (loss) at the end of the period	(42,798)	(75,263)
Defined Benefit Plans | Postretirement Plan
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income (loss) at the beginning of the period	(24,779)	(15,479)
Other comprehensive income (loss) before classifications	10,162	(7,356)
Amounts reclassified from accumulated other comprehensive income (loss)	(1,347)	(1,944)
Net current-period other comprehensive income (loss)	8,815	(9,300)
Accumulated other comprehensive income (loss) at the end of the period	(15,964)	(24,779)
Foreign Exchange
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income (loss) at the beginning of the period	951	253
Other comprehensive income (loss) before classifications	1,012	698
Net current-period other comprehensive income (loss)	1,012	698
Accumulated other comprehensive income (loss) at the end of the period	$ 1,963	$ 951