Document and Entity Information - shares	9 Months Ended
	Apr. 30, 2018	May 24, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	COPART INC
Entity Central Index Key	0000900075
Current Fiscal Year End Date	--07-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Apr. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus (i.e. Q1,Q2,Q3,FY)	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		232,278,137