Acquisitions - Integral Systems, Inc. (Details) (USD $)	3 Months Ended								12 Months Ended			0 Months Ended				0 Months Ended	1 Months Ended	12 Months Ended		0 Months Ended
	Dec. 30, 2012	Sep. 30, 2012	Jun. 24, 2012	Mar. 25, 2012	Dec. 25, 2011	Sep. 25, 2011	Jun. 26, 2011	Mar. 27, 2011	Dec. 30, 2012	Dec. 25, 2011	Dec. 26, 2010	Jul. 27, 2011 Senior notes Senior Notes due June 2017	Mar. 25, 2011 Senior notes Senior Notes due June 2017	Dec. 30, 2012 Senior notes Senior Notes due June 2017	May 19, 2010 Senior notes Senior Notes due June 2017	Jul. 27, 2011 Integral Systems, Inc.	Jul. 31, 2011 Integral Systems, Inc.	Dec. 30, 2012 Integral Systems, Inc.	Dec. 25, 2011 Integral Systems, Inc.	Jul. 27, 2011 Integral Systems, Inc. Senior notes Senior Notes due June 2017
Business Acquisition, Cost of Acquired Entity [Abstract]
Purchase price																$ 241,100,000
Aggregate amount of cash paid																131,400,000
Common stock issued in acquisition, shares																10,400,000	10,400,000
Common stock issued in acquisition, fair value																108,700,000
Replacement stock options issued, fair value																1,000,000
Principal amount outstanding	630,700,000				631,800,000				630,700,000	631,800,000		115,000,000	285,000,000	625,000,000	225,000,000					115,000,000
Stated interest rate percentage												10.00%	10.00%	10.00%	10.00%					10.00%
Issuance premium, percentage																				105.00%
Effective interest rate												8.90%	8.50%							8.90%
Proceeds from issuance of senior notes, gross												122,500,000	314,000,000							120,800,000
Long-term debt premium	18,700,000				22,800,000				18,700,000	22,800,000		5,800,000	20,000,000							5,800,000
Accrued interest												1,700,000	9,000,000							1,800,000
Amount of cash received by each stockholder of Integral																$ 5.00
Number of Kratos shares received by each Integral Systems stockholder for one share of Integral Systems common stock																0.588
Integral Systems stock options exercise price cutoff for exhange terms																$ 13.00
Conversion to Kratos stock options ratio																0.9559
Amount of cash received by each Integral Systems stockholder for each share of Integral Systems restricted stock																$ 13.00
Number of years in business																30 years
Business Combination, Acquired Receivables [Abstract]
Acquired accounts receivable, gross																68,600,000
Acquired accounts receivable, estimated uncollectible																(200,000)
Revenues																		204,200,000	87,300,000
Operating income (loss)	$ (80,300,000)	$ 14,100,000	$ 7,400,000	$ 9,100,000	$ 9,700,000	$ 9,700,000	$ 8,700,000	$ 1,400,000	$ (49,700,000)	$ 29,500,000	$ 23,100,000							$ 10,800,000	$ 7,100,000