Document and Entity Information - USD ($)	12 Months Ended
	Jul. 31, 2020	Sep. 25, 2020	Jan. 31, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Jul. 31, 2020
Document Transition Report	false
Entity Registrant Name	COPART, INC.
Entity Incorporation, State or Country Code	DE
Entity File Number	000-23255
Entity Tax Identification Number	94-2867490
Entity Address, Address Line One	14185 Dallas Parkway
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75254
City Area Code	972
Local Phone Number	391-5000
Title of 12(b) Security	Common Stock, par value $0.0001
Trading Symbol	CPRT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 20,623,302,411
Entity Common Stock, Shares Outstanding		235,971,920
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Central Index Key	0000900075
Current Fiscal Year End Date	--07-31
Documents Incorporated by Reference [Text Block]	Portions of our definitive Proxy Statement for the 2020 Annual Meeting of Stockholders, also referred to in this Annual Report on Form 10-K as our Proxy Statement, which will be filed with the Securities and Exchange Commission, or SEC, pursuant to Regulation 14A within 120 days after the registrant’s fiscal year end of July 31, 2020, have been incorporated by reference in Part III hereof. Except with respect to the information specifically incorporated by reference, the Proxy Statement is not deemed to be filed as a part hereof.