Organization and Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 25, 2016 USD ($) Segment type_of_contract $ / shares	Dec. 27, 2015 USD ($) $ / shares	Dec. 28, 2014 USD ($) $ / shares	Sep. 25, 2016 USD ($)
Significant Accounting Policies Disclosure [Line Items]
Number of reportable segments | Segment	3
Fiscal year duration	364 days	364 days	364 days
Number of different types of contractual arrangements | type_of_contract	3
Number of basic categories of fixed price contracts | type_of_contract	3
Accruals for losses on contracts	$ 17,700,000	$ 3,500,000
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Employee Stock Purchase Plan offering & expense recognition period	6 months
Incremental tax benefits from exercise of stock options	$ 0	$ 0	$ 0
Impact on net income (loss) per common share, basic and diluted (in dollars per share) | $ / shares	$ (0.08)	$ (0.10)	$ (0.06)
Movement in Valuation Allowances and Reserves [Roll Forward]
Provisions	$ 300,000	$ 400,000	$ 1,500,000
Cash and Cash Equivalents [Abstract]
Restricted cash	500,000	700,000
Interest Income (Expense), Net [Abstract]
Interest expense incurred primarily on the Company’s Senior Secured Notes	(34,700,000)	(36,000,000)	(39,400,000)
Miscellaneous interest income	0	0	200,000
Interest expense, net	(34,700,000)	(36,000,000)	(39,200,000)
Foreign currency transaction gain (loss)	$ 400,000	(800,000)	0
Minimum
Significant Accounting Policies Disclosure [Line Items]
Fiscal year duration	364 days
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-based incentive award vesting period	5 years
Goodwill and Other Intangible Assets, Net [Abstract]
Useful life of finite-lived intangible assets	1 year
Maximum
Significant Accounting Policies Disclosure [Line Items]
Fiscal year duration	371 days
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-based incentive award vesting period	10 years
Goodwill and Other Intangible Assets, Net [Abstract]
Useful life of finite-lived intangible assets	15 years
Buildings and improvements | Minimum
Property and Equipment [Abstract]
Useful life of property and equipment	15 years
Buildings and improvements | Maximum
Property and Equipment [Abstract]
Useful life of property and equipment	39 years
Machinery and equipment | Minimum
Property and Equipment [Abstract]
Useful life of property and equipment	3 years
Machinery and equipment | Maximum
Property and Equipment [Abstract]
Useful life of property and equipment	10 years
Computer equipment and software | Minimum
Property and Equipment [Abstract]
Useful life of property and equipment	1 year
Computer equipment and software | Maximum
Property and Equipment [Abstract]
Useful life of property and equipment	10 years
Vehicles, furniture, and office equipment | Maximum
Property and Equipment [Abstract]
Useful life of property and equipment	5 years
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 1,800,000	1,900,000	2,200,000
Provisions	300,000	400,000	1,500,000
Write-offs/Recoveries	(400,000)	(500,000)	(1,800,000)
Balance at End of Year	1,700,000	1,800,000	1,900,000
Continuing operations
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Stock-based compensation expense, amount recognized in the consolidated financial statements	5,100,000	6,100,000	3,600,000
Selling, general and administrative expenses
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Stock-based compensation expense, amount recognized in the consolidated financial statements	5,100,000	6,100,000	$ 3,600,000
Kratos Government Solutions (KGS) | Building facility
Property and Equipment [Abstract]
Carrying value of building held-for-sale				$ 1,900,000
Remeasured fair value of building held-for-sale	500,000
Impairment loss on building reclassified from held-for-sale to held	$ 1,400,000
Stock options | Maximum
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-based incentive award vesting period	6 years
Purchase order not received
Significant Accounting Policies Disclosure [Line Items]
Accounts receivable	$ 2,000,000	$ 1,700,000