Contingencies	3 Months Ended
Contingencies	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Highway products litigation We previously reported the filing of a False Claims Act (“FCA”) complaint in the United States District Court for the Eastern District of Texas, Marshall Division (“District Court”) styled Joshua Harman, on behalf of the United States of America, Plaintiff/Relator v. Trinity Industries, Inc., Defendant, Case No. 2:12-cv-00089-JRG (E.D. Tex.). In this case, in which the U.S. Government declined to intervene, the relator, Mr. Joshua Harman, alleged the Company violated the FCA pertaining to sales of the Company's ET-Plus® System, a highway guardrail end-terminal system (“ET Plus”). On October 20, 2014, a trial in this case concluded with a jury verdict stating that the Company and its subsidiary, Trinity Highway Products, LLC (“Trinity Highway Products”), “knowingly made, used or caused to be made or used, a false record or statement material to a false or fraudulent claim," and the District Court entered judgment on the verdict in the total amount of $682.4 million. On September 29, 2017, the United States Court of Appeals for the Fifth Circuit ("Fifth Circuit") reversed the District Court’s $682.4 million judgment and rendered judgment as a matter of law in favor of the Company and Trinity Highway Products. On January 7, 2019, the United States Supreme Court denied Mr. Harman's petition for certiorari seeking review of the Fifth Circuit's decision. The denial of Mr. Harman's petition ended this action. State, county, and municipal actions Mr. Harman also has separate state qui tam actions currently pending pursuant to: the Virginia Fraud Against Taxpayers Act (Commonwealth of Virginia ex rel. Joshua M. Harman v. Trinity Industries, Inc. and Trinity Highway Products, LLC, Case No. CL13-698, in the Circuit Court, Richmond, Virginia); the Massachusetts False Claims Act (Commonwealth of Massachusetts ex rel. Joshua M. Harman Qui Tam v. Trinity Industries, Inc. and Trinity Highway Products, LLC, Case No. 1484-CV-02364, in the Superior Court Department of the Trial Court); the New Jersey False Claims Act (State of New Jersey ex rel. Joshua M. Harman v. Trinity Industries, Inc. and Trinity Highway Products, LLC, Case No.L-1344-14, in the Superior Court of New Jersey Law Division: Mercer County); and the California False Claims Act (State of California ex rel. Joshua M. Harman Qui Tam v. Trinity Industries, Inc. and Trinity Highway Products, LLC, Case No. RG 14721864, in the Superior Court of California, Alameda County). In each of these cases, Mr. Harman alleged the Company violated the respective states' false claims act pertaining to sales of the ET Plus, and he is seeking damages, civil penalties, attorneys’ fees, costs and interest. Also, the respective states’ Attorneys General filed Notices of Election to Decline Intervention in all of these matters, with the exception of the Commonwealth of Virginia Attorney General, who intervened in the Virginia matter. Following the United States Supreme Court’s denial of Mr. Harman’s petition for certiorari, the stays have expired or been lifted by court order in all of the above-referenced state qui tam cases except Virginia. In a similar Tennessee state qui tam action filed by Mr. Harman (State of Tennessee ex rel. Joshua M. Harman v. Trinity Industries, Inc., and Trinity Highway Products, LLC, Case No. 14C2652, in the Circuit Court for Davidson County, Tennessee), at a telephonic hearing on March 16, 2020, the Court orally granted Trinity’s Motion to Dismiss Harman’s Amended Complaint without prejudice. As previously reported, state qui tam actions filed by Mr. Harman in the states of Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Minnesota, Montana, Nevada, and Rhode Island were dismissed. The Company believes these state qui tam lawsuits are without merit and intends to vigorously defend all allegations. Other states could take similar or different actions, and could be considering similar state false claims or other litigation against the Company. The Company has been served in a lawsuit filed November 5, 2015, titled Jackson County, Missouri, individually and on behalf of a class of others similarly situated vs. Trinity Industries, Inc. and Trinity Highway Products, LLC, Case No. 1516-CV23684 (Circuit Court of Jackson County, Missouri). The case is being brought by plaintiff for and on behalf of itself and all Missouri counties with a population of 10,000 or more persons, including the City of St. Louis, and the State of Missouri’s transportation authority. The plaintiff alleges that the Company and Trinity Highway Products did not disclose design changes to the ET Plus and these allegedly undisclosed design changes made the ET Plus allegedly defective, unsafe, and unreasonably dangerous. The plaintiff alleges product liability negligence, product liability strict liability, and negligently supplying dangerous instrumentality for supplier’s business purposes. The plaintiff seeks compensatory damages, interest, attorneys' fees and costs, and in the alternative plaintiff seeks a declaratory judgment that the ET Plus is defective, the Company’s conduct was unlawful, and class-wide costs and expenses associated with removing and replacing the ET Plus throughout Missouri. On December 6, 2017, the Court granted plaintiff's Motion for Class Certification, certifying a class of Missouri counties with populations of 10,000 or more persons, including the City of St. Louis and the State of Missouri's transportation authority that have or had ET Plus guardrail end terminals with 4-inch wide guide channels installed on roadways they own or maintain. A trial date has been scheduled in this case for October 26, 2020. The Company believes this lawsuit is without merit and intends to vigorously defend all allegations. While the financial impacts of these state, county, and municipal actions are currently unknown, they could be material. Based on information currently available to the Company and previously disclosed, we currently do not believe that a loss is probable in any one or more of the actions described under "State, county, and municipal actions," therefore no accrual has been included in the accompanying Consolidated Financial Statements. Because of the complexity of these actions as well as the current status of certain of these actions, we are not able to estimate a range of possible losses with respect to any one or more of these actions. Product liability cases The Company is currently defending product liability lawsuits in several different states that are alleged to involve the ET Plus as well as other products manufactured by Trinity Highway Products. These cases are diverse in light of the randomness of collisions in general and the fact that each accident involving a roadside device, such as an end terminal, or any other fixed object along the highway, has its own unique facts and circumstances. The Company carries general liability insurance to mitigate the impact of adverse judgment exposures in these product liability cases. To the extent that the Company believes that a loss is probable with respect to these product liability cases, the accrual for such losses is included in the amounts described below under "Other matters". Shareholder class actions On January 11, 2016, the previously reported cases styled Thomas Nemky, Individually and On Behalf of All Other Similarly Situated v. Trinity Industries, Inc., Timothy R. Wallace, and James E. Perry, Case No. (2:15-CV-00732) (“Nemky”) and Richard J. Isolde, Individually and On Behalf of All Other Similarly Situated v. Trinity Industries, Inc., Timothy R. Wallace, and James E. Perry, Case No. (3:15-CV-2093) ("Isolde"), were consolidated in the District Court for the Northern District of Texas, with all future filings to be filed in the Isolde case. On May 11, 2016, the Lead Plaintiffs filed their Consolidated Complaint alleging defendants Trinity Industries, Inc., Timothy R. Wallace, James E. Perry, and Gregory B. Mitchell violated Section 10(b) of the Securities Exchange Act of 1934, Rule 10b-5 promulgated thereunder, and defendants Mr. Wallace and Mr. Perry violated Section 20(a) of the Securities Exchange Act of 1934 by making materially false and misleading statements and/or by failing to disclose material facts about Trinity's ET Plus and the FCA case styled Joshua Harman, on behalf of the United States of America, Plaintiff/Relator v. Trinity Industries, Inc., Defendant, Case No. 2:12-cv-00089-JRG (E.D. Tex.). The parties reached an agreement to settle all claims in this case without any admission of liability or fault for $7.5 million, and on September 23, 2019, entered into a Stipulation of Settlement. Defendants have denied and continue to deny specifically each and all of the claims and contentions alleged by Lead Plaintiffs in this case. The settlement was subject to final court approval. On September 24, 2019, Lead Plaintiffs filed with the Court an Unopposed Motion for Preliminary Approval of Settlement and Approval of Notice to the Class. On November 12, 2019, the Court entered an Order Preliminarily Approving Settlement and Providing for Notice, and on March 31, 2020, the Court granted final approval of the settlement and dismissed the case with prejudice. Other matters The Company is involved in claims and lawsuits incidental to our business arising from various matters, including product warranty, personal injury, environmental issues, workplace laws, and various governmental regulations. The Company evaluates its exposure to such claims and suits periodically and establishes accruals for these contingencies when a range of loss can be reasonably estimated. The range of reasonably possible losses for such matters is $19.3 million to $32.5 million, which includes our rights in indemnity and recourse to third parties of approximately $16.5 million, which is recorded in other assets on our Consolidated Balance Sheet as of March 31, 2020. This range includes any amounts related to the Highway Products litigation matters described above in the section titled “Highway products litigation." At March 31, 2020, total accruals of $21.0 million, including environmental and workplace matters described below, are included in accrued liabilities in the accompanying Consolidated Balance Sheets. The Company believes any additional liability would not be material to its financial position or results of operations. Trinity is subject to remedial orders and federal, state, local, and foreign laws and regulations relating to the environment and the workplace. The Company has reserved $1.3 million to cover our probable and estimable liabilities with respect to the investigations, assessments, and remedial responses to such matters, taking into account currently available information and our contractual rights to indemnification and recourse to third parties. However, estimates of liability arising from future proceedings, assessments, or remediation are inherently imprecise. Accordingly, there can be no assurance that we will not become involved in future litigation or other proceedings involving the environment and the workplace or, if we are found to be responsible or liable in any such litigation or proceeding, that such costs would not be material to the Company. We believe that we are currently in substantial compliance with environmental and workplace laws and regulations.