Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation — Interim Financial Statements Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") have been condensed or omitted pursuant to such rules and regulations. These statements include all adjustments (consisting of normal recurring adjustments) management believes are necessary to fairly state the results of operations, comprehensive income, financial position, changes in shareholders' equity, and cash flows. The Company's management believes the disclosures are adequate to make the information presented not misleading when read in conjunction with the audited consolidated financial statements and the notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the Securities and Exchange Commission on March 2, 2020. Operating results for the three and six months ended June 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020. There are many uncertainties related to the COVID-19 global pandemic that could negatively affect the Company's results of operations, financial position, and cash flows. In response to the expected economic effects of COVID-19, the Company implemented and plans to continue various cost reduction initiatives, including, but not limited to reductions to salary costs and unpaid furloughs; the restructuring actions as discussed in Note 4, Restructuring Charges, Net and Asset Impairments; and the deferral of the Company’s portion of its 2020 employer paid payroll taxes and its U.S. qualified pension plan contributions under the Coronavirus Aid, Relief, and Economic Security Act. At June 30, 2020, the Company was in compliance with all financial covenants under its credit agreement. On May 5, 2020, the Company entered into a third amendment to its credit agreement to increase the maximum leverage ratio and decrease the minimum interest coverage ratio. The amendment is discussed in more detail in Note 10, Debt and Other Financing Arrangements.
Reclassifications	Reclassifications: Certain amounts in the prior period have been aggregated or disaggregated to conform to current year presentation. These reclassifications included reclassifying amounts from restructuring charges, net and asset impairments to cost of sales (exclusive of depreciation and amortization), and selling, general, and administrative expenses. These reclassifications affected the three and six months ended June 30, 2019 and have no effect on previously reported net income within the condensed consolidated statements of income (loss), other comprehensive income (loss) within the condensed consolidated statements of comprehensive income (loss), and the cash (used) provided by operating, investing or financing activities within the condensed consolidated statements of cash flows.
Redeemable noncontrolling interests	Redeemable noncontrolling interests: The Company has noncontrolling interests with redemption features. These redemption features could require the Company to make an offer to purchase the noncontrolling interests in the event of a change in control of Tenneco Inc. or certain of its subsidiaries or the passage of time.
Earnings (loss) per share	Earnings (loss) per share: Basic earnings (loss) per share is calculated by dividing net earnings (loss) by the weighted average shares outstanding during the period. Diluted earnings (loss) per share reflects the weighted average effect of all potentially dilutive securities from the date of issuance.
New Accounting Pronouncements	New Accounting Pronouncements Adoption of New Accounting Standards Income Taxes — In December 2019, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update ("ASU") 2019-12: Simplifying the Accounting for Income Taxes (Topic 740), which removes certain exceptions to the general principles in Topic 740 and improves consistent application of and simplifies U.S. GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The ASU allows certain simplifications in the annual effective tax rate computations, which did not have a material effect on the financial statements. The Company early adopted this ASU on a prospective basis beginning January 1, 2020. Intangibles — On January 1, 2020, the Company adopted ASU 2018-15, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which includes amendments to align the accounting for costs incurred to implement a cloud computing arrangement that is a service contract with the guidance on capitalizing costs associated with developing or obtaining internal-use software. The Company adopted this guidance on a prospective basis beginning January 1, 2020 and the effects of the adoption were not material on the consolidated financial statements. Retirement benefits — In August 2018, the FASB issued ASU 2018-14, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20). The new standard (i) requires the removal of disclosures that are no longer considered cost beneficial; (ii) clarifies specific requirements of certain disclosures; and (iii) adds new disclosure requirements, including reasons for significant gains and losses related to changes in the benefit obligation. The amendments in this update are effective for fiscal years ending after December 15, 2020. The Company will adopt the enhanced disclosures in the consolidated financial statements for the year ending December 31, 2020.