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Significant Accounting Policies (Details) $ in Thousands		12 Months Ended
Significant Accounting Policies (Details) $ in Thousands	May 13, 2021 USD ($) store	Apr. 30, 2022 USD ($) store segment people merchandise_category state	Apr. 30, 2021 USD ($)	Apr. 30, 2020 USD ($)	Apr. 30, 2019 USD ($)
Accounting Policies [Abstract]
Number of stores \| store		2,452
Number of states in which entity operates \| state		16
Population of communities (many less than) \| people		5,000
Concentration Risk
Goodwill		$ 612,934	$ 161,075
Shareholders' equity		2,240,838	1,932,679	$ 1,643,205	$ 1,408,769
Deferred income taxes		520,472	439,721
Contract liability		41,577	30,719
Excess of current cost over the stated LIFO Value		114,731	93,158
Asset impairment charges		1,056	3,846	$ 1,177
Discounted liability of asset retirement obligation		28,604	24,411
Self insurance reserve		$ 53,752	50,526
Number of operating segments \| segment		1
Number of reportable segments \| segment		1
Number of merchandise categories \| merchandise_category		3
Buchanan Energy
Accounting Policies [Abstract]
Number of stores \| store	92
Concentration Risk
Goodwill	$ 254,679
Contractual customer relationships	$ 31,100
Useful life	15 years
Gift Cards
Concentration Risk
Contract liability		$ 15,509	13,096
Capitalized software costs
Concentration Risk
Finite-lived intangible assets		$ 41,337	$ 42,881
Capitalized software costs \| Minimum
Concentration Risk
Intangible asset useful life		3 years
Capitalized software costs \| Maximum
Concentration Risk
Intangible asset useful life		13 years
Customer Relationships
Concentration Risk
Finite-Lived Intangible Assets, Net		$ 29,027
Finite-Lived Intangible Assets, Accumulated Amortization		$ 2,073
Customer Relationships \| Buchanan Energy
Concentration Risk
Useful life	15 years