Amortizable Intangible Assets and Unamortizable Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended
	Oct. 29, 2016	Oct. 31, 2015	Apr. 30, 2016
Intangible Assets by Major Class [Line Items]
Gross Carrying Amount	$ 25,430	$ 25,306
Accumulated Amortization	(24,181)	(23,402)
Total	1,249	1,904
Unamortizable intangible assets	309,294	313,134
Total amortizable and unamortizable, intangible assets	310,543	315,038	$ 310,904
Trade name
Intangible Assets by Major Class [Line Items]
Unamortizable intangible assets	293,400	293,400
Publishing contracts
Intangible Assets by Major Class [Line Items]
Unamortizable intangible assets	15,894	19,734
Technology
Intangible Assets by Major Class [Line Items]
Gross Carrying Amount	10,710	10,710
Accumulated Amortization	(9,793)	(9,385)
Total	$ 917	$ 1,325
Technology | Minimum
Intangible Assets by Major Class [Line Items]
Useful Life	5 years	5 years
Technology | Maximum
Intangible Assets by Major Class [Line Items]
Useful Life	10 years	10 years
Distribution contracts
Intangible Assets by Major Class [Line Items]
Useful Life	10 years	10 years
Gross Carrying Amount	$ 8,325	$ 8,325
Accumulated Amortization	(8,053)	(7,757)
Total	272	568
Other
Intangible Assets by Major Class [Line Items]
Gross Carrying Amount	6,395	6,271
Accumulated Amortization	(6,335)	(6,260)
Total	$ 60	$ 11
Other | Minimum
Intangible Assets by Major Class [Line Items]
Useful Life	3 years	3 years
Other | Maximum
Intangible Assets by Major Class [Line Items]
Useful Life	10 years	10 years