Acquired Intangible Asset Net - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2014	Apr. 30, 2014
Acquired Intangible Assets Amortization [Line Items]
Acquired intangible assets	$ 12,915	$ 13,388
Discontinued Operations
Acquired Intangible Assets Amortization [Line Items]
Acquired intangible assets	$ 0	$ 32,813

Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph ((a)(1),(b))

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

Name:	us-gaap_IntangibleAssetsNetExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant