Stock-Based Compensation - Summary of Grants of Performance-Based Restricted Stock Units Associated with Senior Executives and Key Employees (Detail) - Performance-Based Restricted Stock Units [Member] - $ / shares						9 Months Ended
		Jul. 18, 2019		Aug. 02, 2018		Jan. 31, 2021
Senior Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance-Based Restricted Stock Units Awarded		93,653	[1],[2]	86,599	[1],[2]	0
Restricted Stock Units Expected to Vest	[2],[3]	2,217		3,871
Price Per Share	[2]	$ 19.04	[4]	$ 18.51	[5]
Vesting Period	[2]	3 years		3 years
Key Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance-Based Restricted Stock Units Awarded		29,227	[1],[6]	47,800	[1],[6]	0
Restricted Stock Units Expected to Vest	[3],[6]	1,914		2,318
Price Per Share	[6],[7]	$ 18.49		$ 24.35
Vesting Period	[6]	3 years		3 years

[1] Amounts represent the maximum number of common stock shares that could be earned if certain performance targets are met as defined in the related restricted stock unit agreements.

[2] Performance-based restricted stock units awarded to senior executives.

[3] Compensation cost is based on an assessment each reporting period to determine the probability of whether or not certain performance goals will be met as of the end of the vesting period, and in turn the number of shares that are expected to be awarded at the end vesting period. These amounts represent the number of shares that were expected to vest as of January 31, 2021.

[4] Price per share represents the fair market value per share ($1.03 per $1, or an increase of $0.55 to the closing price of our common stock on the date of grant) determined using the Monte Carlo simulation model for the market-based total shareholder return component and the closing price of our common stock ($18.49) for the performance-based component of the performance-based restricted stock units granted to senior executives on July 18, 2019.

[5] Price per share represents the fair market value per share ($0.76 per $1, or a reduction of $5.84 to the closing price of the common stock on the date of grant) determined using the Monte Carlo simulation model for the market-based total shareholder return component and the closing price of our common stock ($24.35) for the performance-based component of the performance-based restricted stock units granted to senior executives on August 2, 2018.

[6] Performance-based restricted stock units awarded to key employees.

[7] Price per share represents the closing price of our common stock on the date of grant.