Document and Entity Information - shares	3 Months Ended
	Mar. 27, 2016	Apr. 29, 2016
Document And Entity Information
Entity Registrant Name	KRATOS DEFENSE & SECURITY SOLUTIONS, INC.
Entity Central Index Key	0001069258
Current Fiscal Year End Date	--12-25
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 27, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		59,670,226