Incapsula - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended		0 Months Ended	1 Months Ended
	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Nov. 05, 2009	Mar. 31, 2010	Jan. 31, 2012	Jul. 31, 2011
Subsidiary or Equity Method Investee [Line Items]
Value of goodwill on the acquisition date		$ 34,972,000	0
Purchase Right valuation description		Exercise of the Purchase Right was solely within the Company's control and the price for the remaining ownership interest was to be based on an Incapsula enterprise valuation calculated as the greater of (i) eight times Incapsula's prior 12 months trailing revenues or (ii) seven times the aggregate amount Incapsula had raised in connection with its Series A Convertible Preferred Stock financings.
Non-controlling interest reclassified to additional paid-in capital	2,800,000
Performance-Based Award [Member] | Restricted Stock Units for Common Stock [Member]
Subsidiary or Equity Method Investee [Line Items]
Business acquisition, shares issued			264,878
Incapsula Acquisition [Member]
Subsidiary or Equity Method Investee [Line Items]
Amount paid for remaining outstanding capital stock	7,700,000
Business acquisition, shares issued	124,088
Incapsula Acquisition [Member] | Assumed Outstanding Options [Member]
Subsidiary or Equity Method Investee [Line Items]
Business acquisition, shares issued	48,359
Incapsula Acquisition [Member] | 15-Month Holdback [Member]
Subsidiary or Equity Method Investee [Line Items]
Business acquisition, shares issued	34,485
Common stock subject to holdback, period	15 months
Incapsula [Member] | Restricted Stock Units for Common Stock [Member]
Subsidiary or Equity Method Investee [Line Items]
Shares issued or issuable, as-converted to common stock-basis			198,825
Series A Convertible Preferred Stock [Member] | Incapsula [Member]
Subsidiary or Equity Method Investee [Line Items]
Equity method investments, shares				5,000,000	6,666,666
Ownership interest				58.00%	76.00%
Value assigned to license				0
Net assets				0
Value of goodwill on the acquisition date				0
Cash consideration					3,000,000
Value assigned to Purchase Right		0
Series A-1 Convertible Preferred Stock [Member] | Incapsula [Member]
Subsidiary or Equity Method Investee [Line Items]
Number of shares to be purchased if certain milestones were achieved					8,750,000
Cash consideration for milestones achieved					7,000,000
Value assigned to forward contract					0
Series A-1 Preferred Stock [Member] | Incapsula [Member]
Subsidiary or Equity Method Investee [Line Items]
Equity method investments, shares						4,375,000	4,375,000
Ownership interest						85.00%	82.00%
Cash consideration						$ 3,500,000	$ 3,500,000