Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017	Apr. 30, 2016
Income from continuing operations before income taxes
United States		$ 111,516	$ 122,196	$ 115,750
Foreign		17,374	8,544	9,293
Income before income taxes		128,890	130,740	125,043
Federal:
- current		21,206	35,606	32,403
- deferred		16,401	2,349	3,559
State:
- current		4,886	5,194	4,750
- deferred		1,075	(1,703)	859
Foreign:
- current		3,820	2,388	2,345
- deferred		(93)	(78)	164
Total income tax expense		$ 47,295	$ 43,756	$ 44,080
Reconciliation of effective tax rate as it differs from the U.S. federal income tax rate
Statutory tax rate (as a percent)		30.40%	35.00%	35.00%
Increase (reduction) in income taxes resulting from:
Re-measurement of deferred taxes for changes in statutory U.S. tax rate (as a percent)		7.80%
State income taxes, net of federal benefit (as a percent)		3.30%	2.70%	3.40%
U.S. manufacturing benefit (as a percent)		(1.50%)	(2.40%)	(2.50%)
Change in valuation allowance (as a percent)		(0.30%)	(1.00%)	(0.30%)
U.S. research tax credits (as a percent)		(1.90%)
Miscellaneous items (as a percent)		(1.10%)	(0.80%)	(0.30%)
Effective tax rate (as a percent)		36.70%	33.50%	35.30%
Charge recorded to reflect net effect of the Tax Act		$ 10,200
Deferred tax charge from revaluing net U.S. deferred tax assets		10,000
Provisional tax charge related to the one-time transition tax		$ 200
Effect rate of transition tax related to liquid assets (as a percent)		15.50%
Effect rate of transition tax related to remaining unremitted foreign earnings and profit (as a percent)		8.00%
Undistributed earnings, reinvested		$ 45,100
Potential deferred tax attributable to undistributed foreign earnings		2,600
Assets
Deferred and other compensation		18,326	$ 26,689
State income tax - net operating losses, credits and other		5,050	4,927
Warranty		5,348	8,261
Rent		2,971	4,768
Workers' compensation		2,714	3,707
Employee benefits		2,343	3,752
Pension			1,299
Other			3,364
Valuation allowance		(1,224)	(1,786)
Total deferred tax assets		35,528	54,981
Liabilities
Property, plant and equipment		(7,684)	(8,453)
Inventory		(1,531)	(3,052)
Goodwill and other intangibles		(3,575)	(3,345)
Pension		(1,230)
Other		(243)
Net deferred tax assets		21,265	$ 40,131
Deferred tax assets associated with loss carryforwards
Various U.S. state net operating losses (excluding federal tax effect)		4,804
Foreign capital losses		17
Future taxable income needed to fully recover net deferred tax assets		$ 72,000
Forecast
Reconciliation of effective tax rate as it differs from the U.S. federal income tax rate
Statutory tax rate (as a percent)	21.00%