Share-Based Compensation - Additional Information (Detail) | Aug. 01, 2016shares | Feb. 01, 2014shares | Jun. 30, 2018shares | May 31, 2018shares | Jan. 31, 2018shares | Dec. 31, 2017shares | Apr. 29, 2017shares | Mar. 31, 2017shares | Feb. 28, 2017shares | May 31, 2016shares | Apr. 30, 2016shares | Mar. 31, 2016shares | May 31, 2015Installmentshares | Mar. 31, 2015shares | Jul. 28, 2019shares | Jul. 28, 2018USD ($)$ / sharesshares | Apr. 28, 2018shares | Jul. 29, 2017$ / shares | Jul. 28, 2018USD ($)$ / sharesshares | Jul. 29, 2017$ / sharesshares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Maximum disposal restricted percentage of RSU | | | | | | | | | | | | | | | | | | | 50.00% | |
Number of options granted | | | | | | | | | | | | | | | | | | | 196,000 | |
Vesting period | | | 3 years | | | | | | | | | | | | | | | | | |
Options granted weighted-average fair value per share | $ / shares | | | | | | | | | | | | | | | | $ 7.42 | | $ 5.62 | $ 7.41 | $ 4.46 |
Reservation of shares under Stock Purchase Plan | | | | | | | | | | | | | | | | | | | 247,500 | |
Employee Stock Purchase Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Employee Stock Purchase Plan discount rate | | | | | | | | | | | | | | | | | | | 15.00% | |
Shares purchase under Employee Stock Purchase Plan | | | | | | | | | | | | | | | | | | | 2,342 | 2,897 |
Shares available for grant under the Plan | | | | | | | | | | | | | | | | 36,865 | | | 36,865 | |
2018 Equity Incentive Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Shares authorized for grant under the Plan | | | | | | | | | | | | | | | | 650,000 | | | 650,000 | |
Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | | | | 50,000 | | | | 50,000 | | 50,000 | | | | | | |
Other Key Employees [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | | | | | | | | | | 35,000 | | | | | | |
Certain Key Employees [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | 40,000 | | | | | | 37,000 | | | | | | | | | | |
Chief Financial Officer [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | 5,000 | | | | | | | | | | | | | | | | | | | |
Certain Other Key Employees [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | | | 52,189 | | 52,189 | | | | | | | | | | | |
Non-Employee Director [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Granting percentage of shares | | | | | | | | | | | | | | | | | | | 25.00% | |
Director compensation amount, fiscal 2018 | $ | | | | | | | | | | | | | | | | | | | $ 65,000 | |
Director compensation amount, fiscal 2019 | $ | | | | | | | | | | | | | | | | | | | 75,000 | |
Chairman of Board [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Non-employee director received restricted stock award value | $ | | | | | | | | | | | | | | | | | | | 6,000 | |
Chairs of Audit and Compensation Committees [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Non-employee director received restricted stock award value | $ | | | | | | | | | | | | | | | | | | | 4,000 | |
Board [Member] | Nonqualified Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | | 5,000 | | | | | | | | | | | | | | |
New Chief Executive Officer [Member] | Nonqualified Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | 50,000 | | | | | | | | | | | | | | | |
Stock Options [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | 126,000 | | | | | | | | | | | | | | | | | |
Unrecognized compensation expense related to options | $ | | | | | | | | | | | | | | | | $ 2,000,000 | | | $ 2,000,000 | |
Unrecognized compensation expense to be recognized, Weighted average period | | | | | | | | | | | | | | | | | | | 2 years 8 months 12 days | |
2014 Restricted Stock Units (RSUs) [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of accelerated vesting shares | | 4,166 | | | | | | | | | | | | | | | | | | |
Number of vesting shares | | | | | | | | | | | 9,300 | | | | | | | | | |
Unrecognized compensation expense to be recognized, Weighted average period | | | | | | | | | | | | | | | | | | | 1 year 3 months 18 days | |
Unrecognized compensation expense related to RSUs and RSAs | $ | | | | | | | | | | | | | | | | $ 1,400,000 | | | $ 1,400,000 | |
2014 Restricted Stock Units (RSUs) [Member] | Third Anniversary [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of vesting shares | | | | | | | | | | | 9,300 | | | | | | | | | |
2014 Restricted Stock Units (RSUs) [Member] | Officer [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Cumulative budgeted net sales target measurement period | | | | | | | | | | | | | | | | | | | 2014 through 2016 | |
2014 Restricted Stock Units (RSUs) [Member] | Officer [Member] | Net Sales Target [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stock unit vested percentage | | | | | | | | | | | | | | | | | | | 50.00% | |
2014 Restricted Stock Units (RSUs) [Member] | Officer [Member] | ORONA Target [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stock unit vested percentage | | | | | | | | | | | | | | | | | | | 25.00% | |
2014 Restricted Stock Units (RSUs) [Member] | Officer [Member] | Third Anniversary [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stock unit vested percentage | | | | | | | | | | | | | | | | | | | 25.00% | |
2014 Restricted Stock Units (RSUs) [Member] | Board [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | | 675 | | | | | | | | | | | | | | |
2014 Restricted Stock Units (RSUs) [Member] | New Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | 15,000 | | | | | | | | | | | | | | | |
2014 Restricted Stock Units (RSUs) [Member] | Newly Elected Member of Board of Directors [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stocks, granted | | | | | | | | | | | | | | | | | 341 | | | |
RSA [Member] | Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stocks, granted | | | | | | | | | | | | 4,030 | | 537 | | | | | | |
Equity Incentive Plan [Member] | Non-Employee Director [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of stock options grant to each non-employee director | | | | | | | | | | | | | | | | 7,314 | | | | |
Equity Incentive Plan [Member] | Non-Employee Director [Member] | Scenario, Forecast [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of stock options grant to each non-employee director | | | | | | | | | | | | | | | 5,370 | | | | | |
Time Based RSUs [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stocks, granted | | | 44,275 | | | | | | | | | | 80,000 | | | | | | | |
Number of annual vesting installments | Installment | | | | | | | | | | | | | 4 | | | | | | | |
Performance Based RSUs [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stocks, granted | | | | | | | | | | | | | 155,000 | | | | | | | |
Vesting period | | | | | | | | | | | | | 3 years | | | | | | | |
Performance Based Restricted Stock Units RSUs [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Restricted stocks, granted | | | 38,000 | | | | | | | | | | | | | | | | | |
Number of vesting shares | | | | | | | 9,025 | | | | 15,810 | | | | | | 33,638 | | | |
Non Qualified Options [Member] | Newly Elected Member of Board of Directors [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | | | | | | | | | | | | | | | 5,000 | | | |
Non Qualified Options [Member] | Director [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of options granted | | | 25,000 | | | | | | | | | | | | | | | | | |