Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 28, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The information as of June 28, 2020 and for the three and six months ended June 28, 2020 and June 30, 2019 is unaudited. The condensed consolidated balance sheet as of December 29, 2019 was derived from the Company’s audited consolidated financial statements at that date. In the opinion of management, these unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the interim periods presented. The results have been prepared in accordance with the instructions to Form 10-Q and do not necessarily include all information and footnotes necessary for presentation in accordance with accounting principles generally accepted in the U.S. (“GAAP”). These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the related notes included in the Company’s audited annual consolidated financial statements for the fiscal year ended December 29, 2019, included in the Company’s Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (the “SEC”) on February 24, 2020 (the “Form 10-K”). Interim operating results are not necessarily indicative of operating results expected in subsequent periods or for the year as a whole.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company, its 100% owned subsidiaries and its majority owned subsidiaries, FTT Inc. and FTT Core (each as defined below), each of which is 80.1% owned. All inter-company transactions have been eliminated in consolidation. Noncontrolling interest consists of the remaining 19.9% interest in FTT Inc. and FTT Core. See Note 12 for further information related to the redeemable noncontrolling interest.
Fiscal Year	Fiscal Year The Company has a 52/53 week fiscal year ending on the last Sunday of the calendar year. The three month periods ended June 28, 2020 and June 30, 2019 consisted of 13-week periods. The six month periods ended June 28, 2020 and June 30, 2019 consisted of 26-week periods. There are 52 calendar weeks in the fiscal years ending on December 27, 2020 and December 29, 2019.
Accounting Estimates	Accounting EstimatesThere have been no significant changes in the Company’s accounting estimates for the six months ended June 28, 2020 as compared to the accounting estimates described in the Form 10-K.
Accounting Standards Updates	Accounting Standards UpdatesIn June 2016, the FASB issued ASU 2016-13 (“ASU 2016-13”), Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The main objective of this update is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company has adopted ASU 2016-13 effective December 30, 2019. The implementation of this guidance did not have a material impact on its unaudited condensed consolidated financial statements.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts and the related estimated fair values of the Company’s long-term debt financial instruments not measured at fair value on a recurring basis at June 28, 2020 and December 29, 2019 are presented in Note 10. The carrying value of all other financial instruments, including cash equivalents, accounts receivable, unbilled receivables, accounts payable, accrued expenses, billings in excess of cost and earnings on uncompleted contracts, income taxes payable and short-term debt, approximated their estimated fair values at June 28, 2020 and December 29, 2019 due to the short-term nature of these instruments.
Net Income (Loss) per Common Share	Net Income (Loss) per Common Share The Company calculates net income (loss) per share in accordance with FASB Accounting Standards Codification Topic 260, Earnings per Share (Topic 260). Under Topic 260, basic net income (loss) per common share attributable to the Kratos shareholders is calculated by dividing net income (loss) attributable to Kratos by the weighted-average number of common shares outstanding during the reporting period. Diluted net income (loss) per common share attributable to the Kratos shareholders reflects the effects of potentially dilutive securities. The dilutive impact of potentially dilutive common shares is determined by applying the treasury stock method.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 28, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of Presentation The information as of June 28, 2020 and for the three and six months ended June 28, 2020 and June 30, 2019 is unaudited. The condensed consolidated balance sheet as of December 29, 2019 was derived from the Company’s audited consolidated financial statements at that date. In the opinion of management, these unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the interim periods presented. The results have been prepared in accordance with the instructions to Form 10-Q and do not necessarily include all information and footnotes necessary for presentation in accordance with accounting principles generally accepted in the U.S. (“GAAP”). These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the related notes included in the Company’s audited annual consolidated financial statements for the fiscal year ended December 29, 2019, included in the Company’s Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (the “SEC”) on February 24, 2020 (the “Form 10-K”). Interim operating results are not necessarily indicative of operating results expected in subsequent periods or for the year as a whole.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of the Company, its 100% owned subsidiaries and its majority owned subsidiaries, FTT Inc. and FTT Core (each as defined below), each of which is 80.1% owned. All inter-company transactions have been eliminated in consolidation. Noncontrolling interest consists of the remaining 19.9% interest in FTT Inc. and FTT Core. See Note 12 for further information related to the redeemable noncontrolling interest.

Fiscal Year

The Company has a 52/53 week fiscal year ending on the last Sunday of the calendar year. The three month periods ended June 28, 2020 and June 30, 2019 consisted of 13-week periods. The six month periods ended June 28, 2020 and June 30, 2019 consisted of 26-week periods. There are 52 calendar weeks in the fiscal years ending on December 27, 2020 and December 29, 2019.

Accounting Estimates

Accounting EstimatesThere have been no significant changes in the Company’s accounting estimates for the six months ended June 28, 2020 as compared to the accounting estimates described in the Form 10-K.

Accounting Standards Updates

Accounting Standards UpdatesIn June 2016, the FASB issued ASU 2016-13 (“ASU 2016-13”), Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The main objective of this update is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company has adopted ASU 2016-13 effective December 30, 2019. The implementation of this guidance did not have a material impact on its unaudited condensed consolidated financial statements.

Fair Value of Financial Instruments

The carrying amounts and the related estimated fair values of the Company’s long-term debt financial instruments not measured at fair value on a recurring basis at June 28, 2020 and December 29, 2019 are presented in Note 10. The carrying value of all other financial instruments, including cash equivalents, accounts receivable, unbilled receivables, accounts payable, accrued expenses, billings in excess of cost and earnings on uncompleted contracts, income taxes payable and short-term debt, approximated their estimated fair values at June 28, 2020 and December 29, 2019 due to the short-term nature of these instruments.

Net Income (Loss) per Common Share

The Company calculates net income (loss) per share in accordance with FASB Accounting Standards Codification Topic 260, Earnings per Share (Topic 260). Under Topic 260, basic net income (loss) per common share attributable to the Kratos shareholders is calculated by dividing net income (loss) attributable to Kratos by the weighted-average number of common shares outstanding during the reporting period. Diluted net income (loss) per common share attributable to the Kratos shareholders reflects the effects of potentially dilutive securities. The dilutive impact of potentially dilutive common shares is determined by applying the treasury stock method.