Income Taxes (Details) (USD $)	12 Months Ended
	Apr. 27, 2013	Apr. 28, 2012	Apr. 30, 2011
Income before income taxes [Abstract]
United States	$ 63,218,000	$ 60,538,000	$ 21,331,000
Foreign	7,492,000	6,319,000	4,635,000
Income before income taxes	70,710,000	66,857,000	25,966,000
Components of income tax expense [Abstract]
Federal - current	16,873,000	14,392,000	5,935,000
Federal - deferred	1,524,000	(38,396,000)	0
State - current	2,718,000	3,663,000	930,000
State - deferred	493,000	(1,843,000)	700,000
Foreign - current	739,000	2,040,000	1,848,000
Foreign - deferred	1,181,000	(1,907,000)	(820,000)
Total income tax expense (benefit)	23,528,000	(22,051,000)	8,593,000
Effective income tax rate reconciliation [Abstract]
Statutory tax rate (in hundredths)	35.00%	35.00%	35.00%
Increase (reduction) in income taxes resulting from [Abstract]
State income taxes, net of federal benefit (in hundredths)	3.00%	5.00%	4.10%
U.S. manufacturing benefit (in hundredths)	(2.00%)	(2.30%)	(1.90%)
Change in valuation allowance (in hundredths)	0.30%	(69.10%)	13.50%
Change in value of life insurance contracts (in hundredths)	0.00%	0.00%	(0.60%)
Tax benefit associated with VIE acquisition (in hundredths)	0.00%	0.00%	(17.60%)
Gain on sale of marketable securities	(1.60%)	0.00%	0.00%
Miscellaneous items (in hundredths)	0.40%	(1.60%)	0.60%
Effective tax rate (in hundredths)	33.30%	(33.00%)	33.10%
Undistributed earnings, reinvested	7,500,000
Potential deferred tax attributable to undistributed earnings	2,000,000
Assets [Abstract]
Deferred and other compensation	19,510,000	15,043,000
Allowance for doubtful accounts	9,567,000	9,547,000
State income tax - net operating losses, credits and other	6,542,000	5,911,000
Pension	4,632,000	11,220,000
Warranty	5,937,000	5,436,000
Rent	4,697,000	4,590,000
Workers' compensation	3,804,000	3,485,000
Foreign net operating loss	759,000	914,000
Capital loss carryover	0	3,202,000
Other	5,128,000	4,213,000
Valuation allowance	(6,619,000)	(8,258,000)
Total deferred tax assets	53,957,000	55,303,000
Liabilities [Abstract]
Property, plant and equipment	(2,745,000)	(2,573,000)
Net deferred tax assets	51,212,000	52,730,000
Operating Loss Carryforwards [Line Items]
U.S. federal capital loss	0	3,202,000
Foreign net operating losses	759,000	914,000
Valuation allowances		46,200,000
Estimated future taxable income necessary to fully recover net deferred tax assets	136,300,000
Valuation Allowance [Line Items]
Valuation allowance	8,258,000
Valuation allowance change	(1,639,000)
Valuation allowance	6,619,000	8,258,000
Unrecognized tax benefits [Roll Forward]
Balance at the beginning of the period	3,909,000	4,492,000	4,805,000
Additions [Abstract]
Positions taken during the current year	338,000	147,000	100,000
Positions taken during the prior year	0	0	229,000
Reductions [Abstract]
Positions taken during the current year	0	0	0
Positions taken during the prior year	(28,000)	(202,000)	(359,000)
Decreases related to settlements with taxing authorities	0	(166,000)	(202,000)
Reductions resulting from the lapse of the statute of limitations	(971,000)	(362,000)	(81,000)
Balance at the end of the period	3,248,000	3,909,000	4,492,000
Decrease in accrued interest and penalties	200,000
Accrued interest and penalties	400,000	600,000
Recognition of unrecognized tax benefit to decrease effective tax rate	800,000
Income tax liability adjustment	200,000
Cash paid for taxes	20,500,000	15,200,000	9,100,000
U.S. Federal [Member]
Valuation Allowance [Line Items]
Valuation allowance	2,114,000
Valuation allowance change	(2,114,000)
Valuation allowance	0
U.S. State [Member]
Operating Loss Carryforwards [Line Items]
Various U.S. state net operating losses (excluding federal tax effect)	10,064,000
Expiration	Fiscal 2014 - 2033
Valuation Allowance [Line Items]
Valuation allowance	6,121,000
Valuation allowance change	343,000
Valuation allowance	6,464,000
Foreign [Member]
Assets [Abstract]
Foreign net operating loss	759,000
Capital loss carryover	23,000
Operating Loss Carryforwards [Line Items]
U.S. federal capital loss	23,000
Foreign net operating losses	759,000
Expiration	Fiscal 2018 - 2029
Valuation Allowance [Line Items]
Valuation allowance	23,000
Valuation allowance change	132,000
Valuation allowance	$ 155,000