Amortizable Intangible Assets and Unamortizable Intangible Assets (Detail) - USD ($) $ in Thousands		6 Months Ended
		Oct. 27, 2018	Oct. 28, 2017	Apr. 28, 2018
Intangible Assets by Major Class [Line Items]
Gross Carrying Amount		$ 17,282	$ 17,204
Accumulated Amortization		(17,157)	(16,638)
Total		125	566
Unamortizable intangible assets	[1]	309,294	309,294
Total amortizable and unamortizable, intangible assets		309,419	309,860	$ 309,649
Trade name
Intangible Assets by Major Class [Line Items]
Unamortizable intangible assets	[1]	293,400	293,400
Publishing contracts
Intangible Assets by Major Class [Line Items]
Unamortizable intangible assets	[1]	15,894	15,894
Technology
Intangible Assets by Major Class [Line Items]
Gross Carrying Amount		10,710	10,710
Accumulated Amortization		(10,608)	(10,200)
Total		$ 102	$ 510
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
Other
Intangible Assets by Major Class [Line Items]
Gross Carrying Amount		$ 6,572	$ 6,494
Accumulated Amortization		(6,549)	(6,438)
Total		$ 23	$ 56
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

[1] In fiscal 2018, the Company determined that no impairment was necessary on its other unamortizable intangible assets. During the 26 weeks ended October 27, 2018, the Company experienced comparable store sales that were lower than planned. The Company has evaluated whether this indicates a potential impairment of unamortizable intangible assets as of October 27, 2018. The Company has considered, among other factors, the Company's fiscal 2019 forecast, significant improvements in its second quarter comparable store sales, and improvements in the current retail environment. Based on that evaluation, the Company determined that there have not been any events or circumstances that indicate that it is more likely than not that the fair value of its unamortizable intangible assets is less than the carrying value. However, the Company's trade name is at risk of impairment if B&N Retail comparable store sales continue to decline, forecasted holiday sales expectations are not met, store closings accelerate, the assumed long-term discount rate increases, or in general the Company does not achieve its forecasted multi-year strategic plan.