Revenue Recognition - Additional Information (Detail) (USD $)	9 Months Ended
	Jan. 31, 2015	May 03, 2014	Jan. 25, 2014
Deferred Revenue Arrangement [Line Items]
Estimated life of NOOK, years	2 years
Nook
Deferred Revenue Arrangement [Line Items]
Recognized over	2 years
Deferred revenue	$ 3,613,000	$ 9,934,000	$ 13,348,000
Nook | Minimum
Deferred Revenue Arrangement [Line Items]
Average percent, NOOK's sales price	0.00%
Nook | Maximum
Deferred Revenue Arrangement [Line Items]
Average percent, NOOK's sales price	4.00%
Annual Fee
Deferred Revenue Arrangement [Line Items]
Non-refundable, after first 30 days, annual fee	$ 25