Document and Entity Information	3 Months Ended
	Mar. 29, 2015	May 01, 2015
Document And Entity Information
Entity Registrant Name	KRATOS DEFENSE & SECURITY SOLUTIONS, INC.
Entity Central Index Key	0001069258
Current Fiscal Year End Date	--12-27
Entity Filer Category	Accelerated Filer
Document Type	10-Q/A
Document Period End Date	Mar. 29, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	true
Amendment Description	This Amendment No. 1 on Form 10-Q/A to the Kratos Defense & Security Solutions, Inc. Quarterly Report on Form 10-Q for the quarter ended March 29, 2015, filed with the Securities and Exchange Commission on May 7, 2015 (the “Form 10-Q”) is being filed solely to make a clerical correction in the number of shares of common stock outstanding as of the close of business on May 1, 2015 reported on the cover of the Form 10-Q.
Entity Common Stock, Shares Outstanding		58,281,685