Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Contract Performance Contingencies - Contract profit margins may include estimates of revenues for matters on which the customer and the Company have not reached agreement, such as settlements in the process of negotiation, contract changes, claims, and requests for equitable adjustment for unanticipated contract costs. These estimates are based upon management's best assessment of the underlying causal events and circumstances and recognized to the extent of expected recovery based upon contractual entitlements and the probability of successful negotiation with the customer. As of June 30, 2020, amounts recognized in connection with claims and requests for equitable adjustment were not material individually or in aggregate. Guarantees of Performance Obligations - From time to time in the ordinary course of business, HII may enter into joint ventures, teaming agreements, and other business arrangements to support the Company's products and services. The Company attempts to limit its exposure under these arrangements to its investment or the extent of obligations under the applicable contract. In some cases, however, HII may be required to guarantee performance of the arrangement's obligations and, in such cases, generally obtains cross-indemnification from the other members of the arrangement. In the ordinary course of business, the Company may guarantee obligations of its subsidiaries under certain contracts. Generally, the Company is liable under such guarantees only if its subsidiary is unable to perform its obligations. Historically, the Company has not incurred any substantial liabilities resulting from these guarantees. As of June 30, 2020, the Company was not aware of any existing event of default that would require it to satisfy any of these guarantees. Environmental Matters - The estimated cost to complete environmental remediation has been accrued when it is probable that the Company will incur such costs in the future to address environmental conditions at currently or formerly owned or leased operating facilities, or at sites where it has been named a Potentially Responsible Party ("PRP") by the Environmental Protection Agency or similarly designated by another environmental agency, and the related costs can be estimated by management. These accruals do not include any litigation costs related to environmental matters, nor do they include amounts recorded as asset retirement obligations. To assess the potential impact on the Company's consolidated financial statements, management estimates the range of reasonably possible remediation costs that could be incurred by the Company, taking into account currently available facts on each site, as well as the current state of technology and prior experience remediating contaminated sites. These estimates are reviewed periodically and adjusted to reflect changes in facts and technical and legal circumstances. Management estimated that as of June 30, 2020, the probable estimable future cost for environmental remediation was immaterial. Factors that could result in changes to the Company's estimates include: modification of planned remedial actions, increases or decreases in the estimated time required to remediate, changes to the determination of legally responsible parties, discovery of more extensive contamination than anticipated, changes in laws and regulations affecting remediation requirements, and improvements in remediation technology. Should other PRPs not pay their allocable share of remediation costs, the Company may incur costs exceeding those already estimated and accrued. In addition, there are certain potential remediation sites where the costs of remediation cannot be reasonably estimated. Although management cannot predict whether new information gained as remediation progresses will materially affect the estimated liability accrued, management does not believe that future remediation expenditures will have a material effect on the Company's consolidated financial position, results of operations, or cash flows. Financial Arrangements - In the ordinary course of business, HII uses letters of credit issued by commercial banks to support certain leases, insurance policies, and contractual performance obligations, as well as surety bonds issued by insurance companies principally to support the Company's self-insured workers' compensation plans. As of June 30, 2020, the Company had $16 million in issued but undrawn letters of credit, as indicated in Note 13: Debt, and $272 million of surety bonds outstanding. U.S. Government Claims - From time to time, the U.S. Government communicates to the Company potential claims, disallowed costs, and penalties concerning prior costs incurred by the Company with which the U.S. Government disagrees. When such preliminary findings are presented, the Company and U.S. Government representatives engage in discussions, from which HII evaluates the merits of the claims and assesses the amounts being questioned. Although the Company believes that the resolution of any of these matters will not have a material effect on its consolidated financial position, results of operations, or cash flows, it cannot predict the ultimate outcome of these matters. Collective Bargaining Agreements - Of the Company's approximately 42,000 employees, approximately 50% are covered by a total of nine collective bargaining agreements and one site stabilization agreement. Newport News has four collective bargaining agreements covering represented employees, which expire in November 2020, November 2021, December 2022, and April 2024. The collective bargaining agreement that expires in November 2021 covers approximately 50% of Newport News employees. Newport News craft workers employed at the Kesselring Site near Saratoga Springs, New York are represented under an indefinite Department of Energy ("DoE") site agreement. Ingalls has five collective bargaining agreements covering represented employees, all of which expire in March 2022. Approximately 25 Technical Solutions employees at various locations are represented by unions and perform work under collective bargaining agreements. The Company believes its relationship with its employees is satisfactory. Collective bargaining agreements generally expire after three years to five years and are subject to renegotiation at that time. The Company does not expect the results of these negotiations, either individually or in the aggregate, to have a material effect on the Company's consolidated results of operations.