Business Combinations - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions					12 Months Ended
	Jun. 04, 2014	Apr. 15, 2014	Nov. 05, 2012	Jun. 12, 2012	Apr. 30, 2015	Apr. 30, 2014	Oct. 31, 2013	Apr. 30, 2013
Business Acquisition [Line Items]
Proceeds from disposition	$ 30,000				$ 30,000
Amount that will be placed into escrow as partial security for the Company's indemnification obligations	4,500
Contingent Consideration Subject to Certain Requirements
Business Acquisition [Line Items]
Contingent consideration acquisition fair value					$ 0	$ 0
FeedMagnet
Business Acquisition [Line Items]
Cash paid in business acquisition		$ 9,329
Business acquisition total consideration		$ 9,329
PowerReviews
Business Acquisition [Line Items]
Business acquisition total consideration				$ 150,800
Proceeds from disposition	30,000
Amount that will be placed into escrow as partial security for the Company's indemnification obligations	$ 4,500
Longboard Media, Inc
Business Acquisition [Line Items]
Cash paid in business acquisition			$ 26,900
Contingent consideration acquisition fair value			4,300
Longboard Media, Inc | Contingent Consideration Subject to Certain Requirements
Business Acquisition [Line Items]
Contingent consideration acquisition fair value							$ 0	$ 1,500
Longboard Media, Inc | Selling, General and Administrative Expenses | Contingent Consideration Subject to Certain Requirements
Business Acquisition [Line Items]
Fair value offset to operating expenses						(1,000)
Longboard Media, Inc | Selling, General and Administrative Expenses | Scenario, Before Adjustment
Business Acquisition [Line Items]
Fair value offset to operating expenses						$ (3,300)
Longboard Media, Inc | Key individuals
Business Acquisition [Line Items]
Contingent consideration acquisition fair value			$ 2,000
Longboard Media, Inc | Accrued Expenses and Other Current Liabilities | Scenario, Before Adjustment
Business Acquisition [Line Items]
Contingent consideration acquisition fair value							$ 0	$ 3,300
Longboard Media, Inc | Common Stock
Business Acquisition [Line Items]
Shares of common stock issued in business acquisition			0.5