Other Balance Sheet Information Product Warranty and Retrofit Activity on Gross Basis (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning Balance	$ 7,724	$ 7,293	$ 7,329	$ 7,438
Adjustments for acquisitions and divestitures	0	0	962	7
Accruals	3,006	3,405	5,369	6,923
Costs incurred	(3,005)	(3,417)	(5,935)	(7,087)
Ending Balance	$ 7,725	$ 7,281	$ 7,725	$ 7,281