Description of Business and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 29, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Our Business and Basis of Presentation	Basis of Presentation Our quarterly financial periods end on the Friday closest to the last day of the calendar quarter (March 29, 2019 for the first quarter of 2019 and March 30, 2018 for the first quarter of 2018), except for the last quarter of the fiscal year, which ends on December 31. For ease of presentation, the quarterly financial statements included herein are described as three months ended. The unaudited interim Condensed Consolidated Financial Statements of Vectrus have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (SEC). Accordingly, certain information and footnote disclosures normally included in annual financial statements prepared in accordance with generally accepted accounting principles in the U.S. (GAAP) have been omitted. These unaudited interim Condensed Consolidated Financial Statements should be read in conjunction with our audited Consolidated Financial Statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2018. It is management’s opinion that these financial statements include all normal and recurring adjustments necessary for a fair presentation of the Company’s financial position and operating results. Net sales and net earnings for any interim period are not necessarily indicative of future or annual results. Our Business Vectrus, Inc. is a leading provider of services to the United States (U.S.) government worldwide. We operate as one segment and offer facility and logistics services and information technology and network communications services. Vectrus was incorporated in the State of Indiana on February 4, 2014. On September 27, 2014, Exelis Inc. (Exelis) completed a spin-off (the Spin-off) of Vectrus, and Vectrus became an independent, publicly traded company.
Leases	Leases Beginning with our January 1, 2019 adoption of the new lease accounting standard, operating leases are included on our Condensed Consolidated Balance Sheets as right-of-use (“ROU”) assets, other accrued liabilities and other non-current liabilities. ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Lease ROU assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit interest rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate as of January 1, 2019 was applied to operating leases in effect as of that date. The operating lease ROU asset also includes any prepaid lease payments and excludes lease incentives. Many of our leases include one or more options to renew or terminate the lease, solely at our discretion. Such options are factored into the lease term when it is reasonably certain that we will exercise the option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. As allowed under ASC Topic 842, we elected the package of practical expedients permitted under the transition guidance which allowed us to carry forward the historical lease classification, assessment of whether a contract was or contained a lease and assessment of initial direct costs. In addition, we have made policy elections to apply the short-term leases practical expedient, whereby leases with a term of twelve months or less are not capitalized and recorded on our balance sheet, and the practical expedient to not separate lease components from nonlease components. The latter expedient is applied to all of our leases. We did not elect to apply the hindsight practical expedient in determining lease terms and assessing impairment of ROU assets.
Reclassifications	Reclassifications Certain reclassifications have been made to the presentation of amounts in our Condensed Consolidated Statement of Cash Flows for the three months ended March 30, 2018 to conform to the current year presentation. Specifically, depreciation and amortization which were combined and disclosed as one amount are now presented separately.
Accounting Standards Issued But Not Yet Effective and Accounting Standards That Were Adopted	RECENT ACCOUNTING PRONOUNCEMENTS Accounting Standards Issued But Not Yet Effective In January 2017, the Financial Accounting Standards Board (FASB) issued ASU 2017-04. The objective of ASU 2017-04 is to simplify the subsequent measurement of goodwill by entities performing their annual goodwill impairment tests by comparing the fair value of a reporting unit, including income tax effects from any tax-deductible goodwill, with its carrying amount and, in instances where the carrying amount exceeds the fair value, recognizing an impairment charge for the amount by which the carrying amount exceeds fair value. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption of ASU 2017-04 is permitted on goodwill impairment tests performed after January 1, 2017. ASU 2017-04 should be applied on a prospective basis. The standard is not expected to have a material impact on our consolidated financial statements. Other new pronouncements issued but not effective are not expected to have a material impact on our financial position, results of operations or cash flows. Accounting Standards That Were Adopted In February 2018, the FASB issued ASU 2018-02, which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (Tax Act). We adopted the provisions of ASU 2018-02 during the first quarter of 2019 and recorded a $0.3 million decrease to accumulated other comprehensive income and a corresponding increase to beginning retained earnings to reflect the changes in the U.S. federal corporate income tax rate as a result of the Tax Act. As a result of the adoption of ASU 2018-02, our policy to release income tax effects in accumulated other comprehensive income is consistent with the underlying book method. In February 2016, the FASB issued ASU 2016-02, with amendments issued in 2018. The objective of ASU 2016-02 is to recognize lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. The standard requires lessees to recognize most leases on the Condensed Consolidated Balance Sheets but does not change the manner in which expenses are recorded in the income statement. We adopted the standard during the first quarter of 2019 using the cumulative-effect adjustment transition method, which applies the provisions of the standard at the effective date without adjusting comparative periods presented. See Note 1,"Description of Business and Summary of Significant Accounting Policies" and Note 10,"Leases" for further information. In 2017, the FASB issued ASU 2017-12, which provided guidance to amend and simplify the application of hedge accounting guidance to better portray the economic results of risk management activities in the financial statements. The guidance expands the ability to hedge nonfinancial and financial risk components, eliminates the requirements to separately measure and report hedge ineffectiveness, as well as eases certain hedge effectiveness assessment requirements. We adopted the provisions of ASU 2017-12 during the first quarter of 2019. Adoption of this guidance did not have a material impact on our financial statements or disclosures.