Document And Entity Information	3 Months Ended
	Jul. 31, 2011	Sep. 06, 2011
Document And Entity Information
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 31, 2011
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2012
Entity Registrant Name	CASEYS GENERAL STORES INC
Entity Central Index Key	0000726958
Current Fiscal Year End Date	--04-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		38,052,409