Contingencies - Warranty (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 17,916	$ 25,821	$ 30,100
Accruals for warranties issued	6,540	5,665	6,827
Changes in liability related to warranties existing in prior periods	(2,677)	(2,790)	3,308
Payments made	(6,302)	(10,780)	(14,414)
Balance at end of period	$ 15,477	$ 17,916	$ 25,821