Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017
Income Taxes
Estimated effects of the transition tax	$ 200
Income from continuing operations before income taxes
United States	73,058	$ 111,516	$ 122,196
Foreign	22,269	17,374	8,544
Income before income taxes	95,327	128,890	130,740
Federal:
- current	17,629	21,206	35,606
- deferred	(2,649)	16,401	2,349
State:
- current	6,199	4,886	5,194
- deferred	(933)	1,075	(1,703)
Foreign:
- current	4,919	3,820	2,388
- deferred	21	(93)	(78)
Total income tax expense	$ 25,186	$ 47,295	$ 43,756
Reconciliation of effective tax rate as it differs from the U.S. federal income tax rate
Statutory tax rate (as a percent)	21.00%	30.40%	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)	(0.20%)	7.80%
State income taxes, net of federal benefit (as a percent)	4.10%	3.30%	2.70%
Tax effect of defined benefit pension plan termination (as a percent)	2.70%
U.S. manufacturing benefit (as a percent)		(1.50%)	(2.40%)
Change in valuation allowance (as a percent)	0.60%	(0.30%)	(1.00%)
U.S. research tax credits (as a percent)	(0.80%)	(1.90%)
Miscellaneous items (as a percent)	(1.00%)	(1.10%)	(0.80%)
Effective tax rate (as a percent)	26.40%	36.70%	33.50%
Undistributed earnings, reinvested	$ 55,600
Potential deferred tax attributable to undistributed foreign earnings	3,100
Assets
Deferred and other compensation	19,603	$ 18,326
State income tax - net operating losses, credits and other	5,346	5,050
Warranty	5,707	5,348
Rent	2,714	2,971
Workers' compensation	2,525	2,714
Employee benefits	1,479	2,343
Federal net operating losses, credits	2,032
Pension	91
Other	2,250
Valuation allowance	(2,312)	(1,224)
Total deferred tax assets	39,435	35,528
Liabilities
Property, plant and equipment	(10,523)	(7,684)
Inventory	(1,615)	(1,531)
Goodwill and other intangibles	(6,627)	(3,575)
Pension		(1,230)
Other		(243)
Net deferred tax assets	20,670	$ 21,265
Deferred tax assets associated with loss carryforwards
Various U.S. state net operating losses (excluding federal tax effect)	5,012
Foreign net operating losses	2,032
Foreign capital losses	17
Future taxable income needed to fully recover net deferred tax assets	$ 69,000