Business Combinations (Acquisition of Coverity, Inc. (Coverity)) - Additional Information (Detail) (Coverity Inc, USD $)	1 Months Ended	3 Months Ended	6 Months Ended
	Mar. 24, 2014	Apr. 30, 2014	Apr. 30, 2014
Business Acquisition [Line Items]
Date of acquisition	Mar. 24, 2014
Cash consideration for acquisition	$ 375,500,000
Deferred revenue gross	68,500,000
Deferred revenue	21,270,000
Goodwill	266,423,000
Identifiable intangibles assets acquired	101,900,000
Acquisition-related costs		3,000,000	3,500,000
Fair value of stock options assumed	$ 15,000,000
Minimum
Business Acquisition [Line Items]
Definite lived intangible asset amortization period			2 years
Maximum
Business Acquisition [Line Items]
Definite lived intangible asset amortization period			8 years