Components of Identifiable Intangible Assets (Detail) (USD $) In Thousands	Sep. 30, 2011	Sep. 30, 2010
Finite-Lived Intangible Assets [Line Items]
Cost	$ 111,753	$ 73,949
Accumulated Amortization	67,439	62,826
Net Book Value	44,314	11,123
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	7,808	7,808
Accumulated Amortization	6,989	6,886
Net Book Value	819	922
Completed technology
Finite-Lived Intangible Assets [Line Items]
Cost	50,975	43,502
Accumulated Amortization	39,235	37,108
Net Book Value	11,740	6,394
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Cost	3,941	3,779
Accumulated Amortization	3,719	3,379
Net Book Value	222	400
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	49,029	18,860
Accumulated Amortization	17,496	15,453
Net Book Value	$ 31,533	$ 3,407