COVER - shares	9 Months Ended
	Sep. 25, 2022	Oct. 28, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 25, 2022
Document Transition Report	false
Entity File Number	001-34460
Entity Registrant Name	KRATOS DEFENSE & SECURITY SOLUTIONS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3818604
Entity Address, Address Line One	1 Chisholm Trail
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Round Rock
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78681
City Area Code	512
Local Phone Number	238-9840
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	KTOS
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		125,956,987
Entity Central Index Key	0001069258
Current Fiscal Year End Date	--12-25
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false