Contingencies - Warranty (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 11,911	$ 14,342	$ 11,663	$ 15,477
Accruals for warranties issued	1,047	1,302	2,170	2,730
Changes in liability related to warranties existing in prior periods	1,480	(437)	3,223	(1,739)
Payments made	(1,877)	(1,606)	(4,495)	(2,867)
Balance at end of period	$ 12,561	$ 13,601	$ 12,561	$ 13,601