Estimated Useful Life of Definite-Lived Intangible Assets (Detail)	12 Months Ended
	Sep. 30, 2012
Completed technology | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Estimated Useful Life	4 years
Completed technology | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Estimated Useful Life	6 years
Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Estimated Useful Life	5 years
Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Estimated Useful Life	15 years
Trade names | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Estimated Useful Life	1 year
Trade names | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Estimated Useful Life	5 years