Document And Entity Information - shares	3 Months Ended
	Sep. 30, 2019	Oct. 15, 2019
Cover [Abstract]
Entity Registrant Name	CACI INTERNATIONAL INC /DE/
Entity Central Index Key	0000016058
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		25,041,979
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Trading Symbol	CACI
Security Exchange Name	NYSE
Entity File Number	001-31400
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	54-1345888
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
Document Quarterly Report	true
Document Transition Report	false