Changes In Intangible Assets And Goodwill (Amortizable Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 28, 2012
Finite-Lived Intangible Assets [Line Items]
Useful Life, years	3
Gross Carrying Amount	$ 310,749
Accumulated Amortization	(55,997)
Total	254,752
Customer Relationships And Other Acquired Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life, minimum, years	3
Useful Life, maximum, years	25
Gross Carrying Amount	271,938
Accumulated Amortization	(27,985)
Total	243,953
Author Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life, years	10
Gross Carrying Amount	18,461
Accumulated Amortization	(16,588)
Total	1,873
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life, minimum, years	5
Useful Life, maximum, years	10
Gross Carrying Amount	5,850
Accumulated Amortization	(2,225)
Total	3,625
Distribution Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life, years	10
Gross Carrying Amount	8,325
Accumulated Amortization	(4,775)
Total	3,550
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life, minimum, years	3
Useful Life, maximum, years	10
Gross Carrying Amount	6,175
Accumulated Amortization	(4,424)
Total	$ 1,751