Discontinued Operations - Additional Information (Detail) - USD ($)			12 Months Ended
	Jun. 04, 2014	Jun. 12, 2012	Apr. 30, 2015	Apr. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition	$ 30,000,000		$ 30,000,000
Amount that will be placed into escrow as partial security for the Company's indemnification obligations	4,500,000
Assets held for sale			0	$ 33,745,000
Claims for indemnification received			0
Loss on disposal of discontinued operations, net of taxes			(10,729,000)
Loss on disposal of discontinued operations, net of tax, recognized in current period			$ (1,537,000)	(9,192,000)
Decrease in estimated cash proceeds				500,000
Incremental transaction costs				$ 400,000
PowerReviews
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business acquisition total consideration		$ 150,800,000
Proceeds from disposition	30,000,000
Amount that will be placed into escrow as partial security for the Company's indemnification obligations	$ 4,500,000