Income Taxes (Details) - USD ($)	3 Months Ended	6 Months Ended
Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Income taxes
Provision (benefit) for income taxes	$ 2,829,000	$ (48,000)	$ (351,000)	$ (3,911,000)
Effective tax benefit rate (as a percent)	29.30%	1.10%	(17.60%)	19.80%
Excess tax benefits	$ 376,000		$ 1,401,000
Reversal of reserve			$ 968,000

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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Value of stock issued as a result of the exercise of stock options.

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

+ References

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