XML 57 R28.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Commitments and Contingencies (Details) | Oct. 31, 2017 lawsuit
--- | ---
Hot Fuel Cases |
Loss Contingencies [Line Items] |
Number of lawsuits | 4

X
- 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 No definition available. + Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of pending claims pertaining to a loss contingency. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349 + Details
Name: | us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_LitigationCaseAxis=casy_MotorFuelTemperatureSalesPracticesHotFuelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |