Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 28, 2018	Jan. 27, 2018	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017	Apr. 30, 2016
Current Federal Tax Expense (Benefit)			$ (6,494)	$ (8,089)	$ 14,872
Current State and Local Tax Expense (Benefit)			(2,035)	2,410	1,819
Current Income Tax Expense (Benefit)			(8,529)	(5,679)	16,691
Deferred Federal Income Tax Expense (Benefit)			(3,681)	(13,250)	(9,238)
Deferred State and Local Income Tax Expense (Benefit)			(850)	(1,514)	(2,723)
Deferred Income Tax Expense (Benefit)			(4,531)	(14,764)	(11,961)
Income Tax Expense (Benefit)			$ (13,060)	$ (20,443)	$ 4,730
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	33.90%	21.00%	34.10%	35.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount			$ 3,911
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability				$ 20,425
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent			6.30%	(0.30%)	(5.80%)
Effective Income Tax Rate Reconciliation, Tax Contingency, Other, Percent			(3.90%)	(0.70%)	25.50%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent			0.00%	(34.20%)	0.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent			10.40%	7.50%	0.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Percent			0.30%	0.20%	(5.50%)
Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent			0.80%	0.90%	(2.30%)
Effective Income Tax Rate Reconciliation, Percent			34.90%	7.50%	46.90%
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals	$ 9,375		$ 10,972	$ 9,375
Deferred Tax Assets, Inventory	8,256		2,969	8,256
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	1,374		1,738	1,374
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Self Insurance	474		518	474
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Deferred Rent	1,095		982	1,095
Deferred Tax Assets, Property, Plant and Equipment	2,803		0	2,803
Deferred Tax Assets, Tax Credit Carryforwards, Other	220		402	220
Deferred Tax Assets, Goodwill and Intangible Assets	9,105		19,903	9,105
Deferred Tax Assets, Operating Loss Carryforwards	5,834		4,928	5,834
Deferred Tax Assets, Other	4,356		8,253	4,356
Deferred Tax Assets, Gross	42,892		50,665	42,892
Deferred Tax Assets, Valuation Allowance	(932)		(1,194)	(932)
Deferred Tax Assets, Net of Valuation Allowance	41,960		49,471	41,960
Deferred Tax Liabilities, Goodwill and Intangible Assets	(44,066)		(40,790)	(44,066)
Deferred Tax Liabilities, Property, Plant and Equipment	0		(6,256)	0
Deferred Tax Liabilities, Gross	(44,066)		(47,046)	(44,066)
Deferred Tax Assets, Net	2,106		2,425	2,106
Unrecognized Tax Benefits	97		91	97	$ 86	$ 21
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions			0	25	40
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions			0	2	25
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities			0	0	0
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions			(6)	(16)	$ 0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 5		4	$ 5
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense			1
Deferred Tax Liabilities, Undistributed Foreign Earnings			200
Deferred Foreign Income Tax Expense (Benefit)			100
One percentage point [Domain]
Current State and Local Tax Expense (Benefit)			374
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards			81,786
State and Local Jurisdiction [Member]
Operating Loss Carryforwards			$ 509