Shareholders' Equity and Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	May 02, 2020	Apr. 27, 2019	Apr. 28, 2018
Stock Options
Outstanding at beginning of year, Shares	2,202
Granted, Shares	182
Canceled or forfeited, Shares	(263)
Exercised, Shares	0
Outstanding at end of year, Shares	2,121	2,202
Shares vested and expected to vest	2,098
Exercisable at end of year, Shares	1,593
Weighted Average Exercise Price Per Share
Outstanding at beginning of year, (usd per share)	$ 10.03
Granted, (usd per share)	7.47
Canceled or forfeited, (usd per share)	8.85
Exercised, (usd per share)	0.00
Outstanding at end of year, (usd per share)	9.96	$ 10.03
Shares vested and expected to vest (usd per share)	9.98
Exercisable at end of year (usd per share)	$ 10.50
Outstanding, beginning of period, weighted average remaining contractual life	4 years 4 months 18 days	4 years 4 months 28 days
Outstanding, end of period, weighted average remaining contractual life	4 years 4 months 18 days	4 years 4 months 28 days
Vested and expected to vest, weighted average remaining contractual life	4 years 4 months 4 days
Exercisable at end of period, weighted average remaining contractual life	3 years 2 months
Outstanding, beginning of period, aggregate intrinsic value	$ 0
Exercised, aggregate intrinsic value	0	$ 98	$ 65
Outstanding, end of period, aggregate intrinsic value	0	$ 0
Shares vested and expected to vest, aggregate intrinsic value	0
Exercisable at end of period, aggregate intrinsic value	$ 0