Contingencies	12 Months Ended
Apr. 30, 2017
Loss Contingency [Abstract]
Contingencies	CONTINGENCIES Environmental compliance The United States Environmental Protection Agency and several states have adopted laws and regulations relating to underground storage tanks used for petroleum products. Several states in which the Company does business have trust fund programs with provisions for sharing or reimbursing corrective action or remediation costs. Management currently believes that substantially all capital expenditures for electronic monitoring, cathodic protection, and overfill/spill protection to comply with existing regulations have been completed. The Company has an accrued liability at April 30, 2017 and 2016 of approximately $283 and $341, respectively, for estimated expenses related to anticipated corrective actions or remediation efforts, including relevant legal and consulting costs. Management believes the Company has no material joint and several environmental liability with other parties. Additional regulations or amendments to the existing regulations could result in future revisions to such estimated expenditures. Legal matters As previously reported, the Company was named as a defendant in four lawsuits (“hot fuel” cases) brought in the federal courts in Kansas and Missouri against a variety of fuel retailers, which were consolidated in the U.S. District Court for the District of Kansas in Kansas City, Kansas as part of the multidistrict “Motor Fuel Temperature Sales Practices Litigation”. On November 20, 2012, the Court preliminarily approved the previously-reported settlement involving the Company, which when approved in final form by the Court following notice to the Class would result in the settlement and dismissal of all claims against Casey’s in the multidistrict litigation. The approved settlement includes, but is not limited to, a commitment on the part of the Company to “sticker” certain information on its fuel pumps and make a monetary payment (which is not considered to be material in amount) to the plaintiff class. An order awarding fees was filed by the Court on February 17, 2016, but is subject to resolution of any appeal to the Tenth Circuit Court of Appeals. From time to time we may be involved in other legal and administrative proceedings or investigations arising from the conduct of our business operations, including, but not limited to, contractual disputes; employment or personnel matters; personal injury and property damage claims; and claims by federal, state, and local regulatory authorities relating to the sale of products pursuant to licenses and permits issued by those authorities. Claims for damages in those actions may be substantial. While the outcome of such litigation, proceedings, investigations, or claims is never certain, it is our opinion, after taking into consideration legal counsel’s assessment and the availability of insurance proceeds and other collateral sources to cover potential losses, that the ultimate disposition of such matters currently pending or threatened, individually or cumulatively, will not have a material adverse effect on our consolidated financial position and results of operation. Other At April 30, 2017, the Company was partially self-insured for workers’ compensation claims in all but one state of its marketing territory. In North Dakota, the Company is required to participate in an exclusive, state managed fund for all workers compensation claims. The Company was also partially self-insured for general liability and auto liability under an agreement that provides for annual stop-loss limits equal to or exceeding approximately $1,000. To facilitate this agreement, letters of credit approximating $21,126 and $20,115, respectively, were issued and outstanding at April 30, 2017 and 2016, on the insurance company’s behalf. The Company also has investments of approximately $223 in escrow as required by one state for partial self-insurance of workers’ compensation claims. Additionally, the Company is self-insured for its portion of employee medical expenses. At April 30, 2017 and 2016, the Company had $37,984 and $35,535, respectively, in accrued expenses for estimated claims relating to self-insurance, the majority of which has been actuarially determined.

CONTINGENCIES

Environmental compliance The United States Environmental Protection Agency and several states have adopted laws and regulations relating to underground storage tanks used for petroleum products. Several states in which the Company does business have trust fund programs with provisions for sharing or reimbursing corrective action or remediation costs.

Management currently believes that substantially all capital expenditures for electronic monitoring, cathodic protection, and overfill/spill protection to comply with existing regulations have been completed. The Company has an accrued liability at April 30, 2017 and 2016 of approximately $283 and $341, respectively, for estimated expenses related to anticipated corrective actions or remediation efforts, including relevant legal and consulting costs. Management believes the Company has no material joint and several environmental liability with other parties. Additional regulations or amendments to the existing regulations could result in future revisions to such estimated expenditures.

Legal matters As previously reported, the Company was named as a defendant in four lawsuits (“hot fuel” cases) brought in the federal courts in Kansas and Missouri against a variety of fuel retailers, which were consolidated in the U.S. District Court for the District of Kansas in Kansas City, Kansas as part of the multidistrict “Motor Fuel Temperature Sales Practices Litigation”. On November 20, 2012, the Court preliminarily approved the previously-reported settlement involving the Company, which when approved in final form by the Court following notice to the Class would result in the settlement and dismissal of all claims against Casey’s in the multidistrict litigation. The approved settlement includes, but is not limited to, a commitment on the part of the Company to “sticker” certain information on its fuel pumps and make a monetary payment (which is not considered to be material in amount) to the plaintiff class. An order awarding fees was filed by the Court on February 17, 2016, but is subject to resolution of any appeal to the Tenth Circuit Court of Appeals.

From time to time we may be involved in other legal and administrative proceedings or investigations arising from the conduct of our business operations, including, but not limited to, contractual disputes; employment or personnel matters; personal injury and property damage claims; and claims by federal, state, and local regulatory authorities relating to the sale of products pursuant to licenses and permits issued by those authorities. Claims for damages in those actions may be substantial. While the outcome of such litigation, proceedings, investigations, or claims is never certain, it is our opinion, after taking into consideration legal counsel’s assessment and the availability of insurance proceeds and other collateral sources to cover potential losses, that the ultimate disposition of such matters currently pending or threatened, individually or cumulatively, will not have a material adverse effect on our consolidated financial position and results of operation.

Other At April 30, 2017, the Company was partially self-insured for workers’ compensation claims in all but one state of its marketing territory. In North Dakota, the Company is required to participate in an exclusive, state managed fund for all workers compensation claims. The Company was also partially self-insured for general liability and auto liability under an agreement that provides for annual stop-loss limits equal to or exceeding approximately $1,000. To facilitate this agreement, letters of credit approximating $21,126 and $20,115, respectively, were issued and outstanding at April 30, 2017 and 2016, on the insurance company’s behalf. The Company also has investments of approximately $223 in escrow as required by one state for partial self-insurance of workers’ compensation claims. Additionally, the Company is self-insured for its portion of employee medical expenses. At April 30, 2017 and 2016, the Company had $37,984 and $35,535, respectively, in accrued expenses for estimated claims relating to self-insurance, the majority of which has been actuarially determined.