Stock-Based Compensation - Narrative (Detail) - USD ($)							3 Months Ended
	Jul. 14, 2016	Jul. 15, 2015	Mar. 03, 2015	Jun. 24, 2014	Jun. 25, 2013	Jul. 11, 2012	Jul. 31, 2016	Aug. 02, 2015	Sep. 16, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options granted							0
2015 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock authorized for issuance									1,200,000
Number of shares available for future equity based grants							1,012,635
2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future equity based grants									0
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options to purchase common stock outstanding							81,600
Number of options exercisable							81,600
Weighted average exercise price for options outstanding							$ 8.44
Weighted average exercise price for options exercisable							$ 8.44
Weighted average contractual term for options outstanding							1 year 1 month 6 days
Weighted average contractual term for options exercisable							1 year 1 month 6 days
Aggregate intrinsic value for options outstanding							$ 1,600,000
Aggregate intrinsic value for options exercisable							1,600,000
Aggregate intrinsic value for options exercised							$ 43,000	$ 814,000
Number of unvested stock option							0
Unrecognized stock based compensation cost							$ 0
Share-based compensation expense							0	0
Performance Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining unrecognized compensation cost							$ 5,000,000
Weighted average period over which unrecognized compensation cost is expected to be recognized							2 years 1 month 6 days
Performance Based Restricted Stock Units [Member] | Selling, general and administrative expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense							$ 761,000	$ 265,000
Performance Based Restricted Stock Units [Member] | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock	$ 28	$ 32.23		$ 17.70	$ 17.12	$ 10.21
Vesting period	3 years	3 years		3 years	3 years	3 years
Performance Based Restricted Stock Units [Member] | Non-employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years	3 years
Closing price of common stock							$ 28.53
Number of shares unvested			16,000
Performance Based Restricted Stock Units [Member] | Requisite Service Period for 16,000 Restricted Stock Units [Member] | Non-employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			28 months
Performance Based Restricted Stock Units [Member] | Fiscal Year 2015 [Member] | Non-employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested							12,000
Weighted average fair value of vested shares							$ 345,000
Weighted average fair value of vested shares, per share							$ 28.77
Performance Based Restricted Stock Units [Member] | Fiscal Year 2014 [Member] | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested							37,192
Weighted average fair value of vested shares							$ 637,000
Weighted average fair value of vested shares, per share							$ 17.12
Performance Based Restricted Stock Units [Member] | Fiscal Year 2013 [Member] | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested								115,855
Weighted average fair value of vested shares								$ 1,200,000
Weighted average fair value of vested shares, per share								$ 10.21
Performance Based Restricted Stock Units [Member] | Maximum [Member] | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares granted	107,880	107,554		102,845	72,380	120,000
Performance Based Restricted Stock Units [Member] | Maximum [Member] | Non-employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares granted	11,549	10,364	28,000