Business Combination, Consideration Transferred, Working Capital Adjustments

No definition available.

Name:	casy_BusinessCombinationConsiderationTransferredWorkingCapitalAdjustments
Namespace Prefix:	casy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Business Combination, Dealer Network, Number Of Stores

+ References

No definition available.

+ Details

Name:	casy_BusinessCombinationDealerNetworkNumberOfStores
Namespace Prefix:	casy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Disposal Group, Not Discontinued Operation, Number Of Property Parcel Disposed Of

+ References

No definition available.

+ Details

Name:	casy_DisposalGroupNotDiscontinuedOperationNumberOfPropertyParcelDisposedOf
Namespace Prefix:	casy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Disposal Group, Not Discontinued Operation, Number Of Stores

+ References

No definition available.

+ Details

Name:	casy_DisposalGroupNotDiscontinuedOperationNumberOfStores
Namespace Prefix:	casy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479907/805-20-50-5

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479328/805-10-50-2

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479405/805-10-25-23

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 8
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479637/805-30-30-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 7
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479637/805-30-30-7

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479328/805-10-50-2

+ Details

Name:	us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479907/805-20-50-1

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481372/852-10-55-10

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482548/350-20-55-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(15))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482598/350-20-45-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the number of stores.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfStores
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-13

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=casy_TermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=casy_NewSeniorUnsecuredTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=casy_BuchananEnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=casy_MinitMartMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=casy_BuchananEnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReportingUnitAxis=casy_RetailReportingUnitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReportingUnitAxis=casy_FuelWholesaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_NE
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_IL
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_IA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_MO
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_TX
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=casy_CircleKMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=casy_PilotCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_TN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_KY
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Acquisitions - Narrative (Details) $ in Thousands		1 Months Ended	12 Months Ended
Acquisitions - Narrative (Details) $ in Thousands	May 13, 2021 USD ($) store	Jun. 30, 2021 USD ($) store	Apr. 30, 2023 USD ($) store	Apr. 30, 2022 USD ($) store	Dec. 16, 2021 USD ($) store
Business Acquisition
Number of stores \| store			2,521
Goodwill			$ 615,342	$ 612,934
Dealer network, number of stores \| store	81
Line of Credit \| Term Loan Facility
Business Acquisition
Maximum borrowing capacity	$ 300,000
Line of Credit \| New Senior Unsecured Term Lon
Business Acquisition
Maximum borrowing capacity					$ 150,000
Buchanan Energy \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition
Number of retail locations divested \| store	3			4
Number of parcels of property divested \| store				1
Consideration received for disposal				$ 41,000
Series of Individually Immaterial Business Acquisitions
Business Acquisition
Number of stores \| store			47
Goodwill			$ 2,408
Purchase price			85,569
Revenue			17,325,000
Net assets acquired and total purchase price			$ 85,569
Minit Mart
Business Acquisition
Number of stores \| store			26
Buchanan Energy
Business Acquisition
Number of stores \| store	92
Goodwill	$ 254,679
Purchase price	$ 577,242
Percentage of voting interested acquired	100.00%
Consideration transferred	$ 571,842
Working capital adjustments	5,400
Acquisition-related transaction costs	8,600
Acquisition-related transaction costs incurred			$ 6,700
Net assets acquired and total purchase price	571,842
Buchanan Energy \| Retail
Business Acquisition
Goodwill	245,516
Buchanan Energy \| Fuel Wholesale
Business Acquisition
Goodwill	$ 9,163
Buchanan Energy \| Nebraska
Business Acquisition
Number of stores \| store	24
Buchanan Energy \| Illinois
Business Acquisition
Number of stores \| store	56
Buchanan Energy \| Iowa
Business Acquisition
Number of stores \| store	5
Buchanan Energy \| Missouri
Business Acquisition
Number of stores \| store	3
Buchanan Energy \| Texas
Business Acquisition
Number of stores \| store	4
Circle K
Business Acquisition
Number of stores \| store		48
Goodwill		$ 31,346
Purchase price		41,416
Net assets acquired and total purchase price		$ 41,416
Pilot
Business Acquisition
Number of stores \| store					40
Goodwill					$ 154,223
Net assets acquired and total purchase price					$ 226,624
Pilot \| Tennessee
Business Acquisition
Number of stores \| store					39
Pilot \| Kentucky
Business Acquisition
Number of stores \| store					1