Summary of Significant Accounting Policies (Details)	12 Months Ended
	Apr. 30, 2022 USD ($) plan $ / shares	Apr. 30, 2021 USD ($) $ / shares	Apr. 30, 2020 USD ($) $ / shares	Apr. 30, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Advertising costs	$ 32,600,000	$ 34,100,000	$ 33,900,000
Impairment of long-lived assets	0	0	0
Impairment of goodwill	0	0	0
Impairment of intangible assets	$ 0	0	0
Number of defined benefit pension plans | plan	2
Operating lease right-of-use assets	$ 108,055,000	123,118,000
Operating lease liability	117,069,000
Cost of sales and distribution	1,630,742,000	1,421,896,000	1,323,771,000
Gross Profit	226,444,000	322,118,000	326,562,000
Operating Income	36,159,000	114,738,000	130,135,000
Income (Loss) Before Income Taxes	(42,979,000)	80,693,000	98,928,000
Income tax expense (benefit)	(13,257,000)	19,500,000	25,275,000
Net income (loss)	$ (29,722,000)	$ 61,193,000	$ 73,653,000
Net earnings (loss) per share, Basic (usd per share) | $ / shares	$ (1.79)	$ 3.61	$ 4.36
Net earnings (loss) per share, Diluted (usd per share) | $ / shares	$ (1.79)	$ 3.59	$ 4.34
Inventories	$ 228,259,000	$ 158,167,000
Total current assets	428,657,000	409,965,000
Total assets	1,632,496,000	1,654,399,000
Deferred income taxes	38,340,000	42,891,000
Other accrued expenses	20,240,000	21,913,000
Total current liabilities	216,228,000	220,447,000
Retained earnings	399,434,000	448,282,000		$ 329,540,000
Total shareholders' equity	772,883,000	756,238,000	$ 711,450,000	632,473,000
Total liabilities and shareholders' equity	1,632,496,000	1,654,399,000
Inventories	(70,386,000)	(34,454,000)	(2,866,000)
Income taxes receivable	(6,206,000)	488,000	1,162,000
Deferred income taxes	(25,717,000)	(12,840,000)	(11,911,000)
Total Comprehensive Income	$ 35,071,000	$ 57,798,000	71,971,000
Percentage of LIFO Inventory	44.00%	43.00%
Deferred income taxes	$ 1,469,000	$ 1,118,000
Net Cash Provided by (Used in) Operating Activities	24,445,000	151,763,000	177,542,000
Previously Reported
Summary Of Significant Accounting Policies [Line Items]
Cost of sales and distribution	1,633,255,000	1,424,739,000	1,321,147,000
Gross Profit	223,931,000	319,275,000	329,186,000
Operating Income	33,646,000	111,680,000	132,262,000
Income (Loss) Before Income Taxes	(45,492,000)	77,435,000	100,548,000
Income tax expense (benefit)	(13,913,000)	18,672,000	25,687,000
Net income (loss)	$ (31,579,000)	$ 58,763,000	$ 74,861,000
Net earnings (loss) per share, Basic (usd per share) | $ / shares	$ (1.90)	$ 3.46	$ 4.43
Net earnings (loss) per share, Diluted (usd per share) | $ / shares	$ (1.90)	$ 3.45	$ 4.42
Inventories	$ 225,746,000	$ 140,282,000
Total current assets	426,144,000	392,080,000
Total assets	1,629,983,000	1,636,514,000
Deferred income taxes		38,348,000
Other accrued expenses	19,584,000
Total current liabilities	215,572,000
Retained earnings	397,577,000	434,940,000		317,420,000
Total shareholders' equity	771,026,000	742,896,000	$ 700,538,000	620,353,000
Total liabilities and shareholders' equity	1,629,983,000	1,636,514,000
Inventories	(67,873,000)	(31,196,000)	(4,486,000)
Income taxes receivable	(6,862,000)
Deferred income taxes		(13,668,000)	(11,499,000)
Total Comprehensive Income	33,214,000	55,368,000	73,179,000
Revision of Prior Period, Change in Accounting Principle, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Cost of sales and distribution	(2,513,000)	(2,843,000)	2,624,000
Gross Profit	2,513,000	2,843,000	(2,624,000)
Operating Income	2,513,000	3,058,000	(2,127,000)
Income (Loss) Before Income Taxes	2,513,000	3,258,000	(1,620,000)
Income tax expense (benefit)	656,000	828,000	(412,000)
Net income (loss)	$ 1,857,000	$ 2,430,000	$ (1,208,000)
Net earnings (loss) per share, Basic (usd per share) | $ / shares	$ 0.11	$ 0.15	$ (0.07)
Net earnings (loss) per share, Diluted (usd per share) | $ / shares	$ 0.11	$ 0.14	$ (0.08)
Inventories	$ 2,513,000	$ 17,885,000
Total current assets	2,513,000	17,885,000
Total assets	2,513,000	17,885,000
Deferred income taxes		4,543,000
Other accrued expenses	656,000
Total current liabilities	656,000
Retained earnings	1,857,000	13,342,000		12,120,000
Total shareholders' equity	1,857,000	13,342,000	$ 10,912,000	$ 12,120,000
Total liabilities and shareholders' equity	2,513,000	17,885,000
Inventories	(2,513,000)	(3,258,000)	1,620,000
Income taxes receivable	656,000
Deferred income taxes		828,000	(412,000)
Total Comprehensive Income	1,857,000	2,430,000	(1,208,000)
Deferred income taxes		4,500,000
Net Cash Provided by (Used in) Operating Activities	$ 1,900,000
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, useful life	6 years
Buildings And Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	15 years
Buildings And Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	30 years
Machinery And Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	3 years
Machinery And Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	12 years
Promotional Display [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization	$ 10,000,000	$ 10,000,000	$ 8,200,000
Promotional Display [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	60 months