Acquisitions - Herley Industries, Inc. (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended			3 Months Ended								12 Months Ended							0 Months Ended		1 Months Ended	12 Months Ended								0 Months Ended
	May 14, 2012	Feb. 11, 2011	Oct. 12, 2010	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	Dec. 30, 2012 Senior notes Senior Notes due June 2017	Jul. 27, 2011 Senior notes Senior Notes due June 2017	Mar. 25, 2011 Senior notes Senior Notes due June 2017	May 19, 2010 Senior notes Senior Notes due June 2017	Mar. 25, 2011 Herley Industries, Inc.	Feb. 11, 2011 Herley Industries, Inc.	Feb. 28, 2011 Herley Industries, Inc.	Dec. 30, 2012 Herley Industries, Inc.	Dec. 25, 2011 Herley Industries, Inc.	Apr. 15, 2011 Herley Industries, Inc.	Mar. 27, 2011 Herley Industries, Inc.	Mar. 25, 2011 Herley Industries, Inc. Preliminary	Mar. 25, 2011 Herley Industries, Inc. Final	Mar. 25, 2011 Herley Industries, Inc. Senior notes Senior Notes due June 2017	Mar. 25, 2011 Herley Industries, Inc. Change in control obligations	Mar. 25, 2011 Herley Industries, Inc. Combined transaction expenses
Business Acquisition, Cost of Acquired Entity [Abstract]
Number of shares acquired																			13.2
Voting interests acquired, percentage																			94.00%
Fair value of non-controlling interest																			$ 16,900,000
Share price used to calculate fair value																			$ 19.00
Non-controlling interest, number of shares																			0.9
Aggregate amount of cash paid																								270,700,000	245,500,000
Conversion to Kratos common stock ratio																			1.3495
Common stock issued to assume the Herley Options (shares)																			0.8		4.9
Common stock issued to assume the Herley Options, fair value																			1,900,000
Purchase price																			272,500,000
Change in control obligations assumed																													4,000,000
Combined transaction expenses																														11,100,000
Common stock issued in acquisition, shares																				4.9	4.9
Purchase price (in dollars per share)																				$ 13.25
Gross proceeds from issuance of common stock	100,000,000	64,800,000	25,800,000																	64,800,000
Proceeds from the issuance of common stock, net of issuance costs	97,000,000	61,100,000	24,700,000									97,000,000	61,100,000	24,700,000						61,100,000
Principal amount outstanding				630,700,000				631,800,000				630,700,000	631,800,000		625,000,000	115,000,000	285,000,000	225,000,000										285,000,000
Stated interest rate percentage															10.00%	10.00%	10.00%	10.00%
Issuance premium, percentage																												107.00%
Number of years in business																			45 years
Business Combination, Acquired Receivables [Abstract]
Acquired accounts receivable, gross																			39,300,000
Acquired accounts receivable, estimated uncollectible																			(200,000)
Business Acquisition, Purchase Price Allocation [Abstract]
Inventoried costs																			42,800,000							47,900,000	42,800,000
Property and equipment																			34,200,000							30,400,000	34,200,000
Revenues																						196,500,000	150,800,000
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								$ 31,400,000	$ 12,700,000