Document And Entity Information - USD ($)	12 Months Ended
	Jun. 30, 2019	Aug. 15, 2019	Dec. 31, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	CACI INTERNATIONAL INC /DE/
Entity Central Index Key	0000016058
Trading Symbol	CACI
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		24,881,546
Entity Public Float			$ 3,520,375,787
Document Type	10-K
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-31400
Entity Tax Identification Number	541345888
Entity Address, Address Line One	1100 North Glebe Road
Entity Address, City or Town	Arlington
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22201
City Area Code	703
Local Phone Number	841-7800