Summary of Accounting Policies (Policies)	6 Months Ended
Summary of Accounting Policies (Policies)	Jun. 30, 2019
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, 2018, which was filed with the Securities and Exchange Commission on March 18, 2019. Operating results for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. The Company expects to separate its businesses to form two new, independent publicly traded companies, an Aftermarket and Ride Performance company ("DRiV") and a new Powertrain Technology company ("New Tenneco"). The Company currently expects the separation of the businesses to occur through a spinoff transaction of DRiV in mid-2020. In preparation for the spinoff, the Company began to manage and report its DRiV businesses through two new operating segments, in the first quarter of 2019, as compared to the three operating segments it had previously reported. The DRiV operating segments consist of Motorparts and Ride Performance. The new Motorparts operating segment consists of the previously reported Aftermarket operating segment as well as the aftermarket portion of the previously reported Motorparts operating segment. The Ride Performance operating segment consists of the previously reported Ride Performance operating segment as well as the OE Braking business that was included in the previously reported Motorparts operating segment. As such, prior period operating segment results and related disclosures have been conformed to reflect the Company's current operating segments. The future New Tenneco consists of two existing operating segments, Powertrain and Clean Air. See Note 17, Segment Information.
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 at fair value in the event of a change in control of Tenneco Inc. or certain of its subsidiaries. The redemption of these redeemable noncontrolling interests is not solely within the Company's control. Accordingly, these noncontrolling interests are presented in the temporary equity section of the Company's condensed consolidated balance sheets. The Company does not believe it is probable the redemption features related to these noncontrolling interest securities will be triggered, as a change in control event is generally not probable until it occurs, except as discussed in
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.
Reclassifications	Reclassifications: Certain amounts in the prior years have been aggregated or disaggregated to conform to current year presentation. These reclassifications have no effect on previously reported earnings before income taxes and noncontrolling interests or net income, other comprehensive income (loss), current or total assets, current or total liabilities, and the cash provided (used) by operating, investing or financing activities within the condensed consolidated financial statements.
New Accounting Pronouncements	New Accounting Pronouncements Adoption of New Accounting Standards Comprehensive income — In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220). The amendments in this update allow a reclassification from accumulated other comprehensive income (loss) to accumulated deficit for stranded tax effects resulting from the Tax Cuts and Jobs Act ("TCJA"). The Company has elected not to adopt the optional reclassification. Leases — In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This update supersedes the lease requirements in Topic 840, Leases. The objective of Topic 842 is to establish the principles that lessees and lessors shall apply to report useful information to users of financial statements about the amount, timing, and uncertainty of cash flows arising from a lease. For public business entities, the standard is effective for financial statements issued for annual periods beginning after December 15, 2018, and interim periods within those annual periods. The Company adopted this update on January 1, 2019 using the modified retrospective method without the recasting of comparative periods’ financial information, as permitted by the transition guidance. The Company adopted the package of practical expedients that allows companies to not reassess its previous conclusions related to contracts that contain leases, existing lease classification, and initial direct costs, and to carry forward its historical conclusions. It elected the land easements practical expedient allowing the Company not to reassess whether existing or expired land easements not accounted for as leases under previous guidance are or contain leases under the new guidance. It also did not adopt the hindsight practical expedient and has also made an accounting policy election to exempt leases with an initial term of twelve months or less from balance sheet recognition. Instead, short-term leases will be expensed over the lease term. As a part of the implementation effort, the Company reviewed its internal control structure and modified and augmented existing controls, as necessary. The adoption of the new standard resulted in the recording of additional lease assets and lease liabilities of $387 million and $383 million, and a reduction of favorable lease intangibles of $4 million as of January 1, 2019. The standard did not materially affect the Company's condensed consolidated financial position or results of operations and had no effect on cash flows. See Note 14, Leases. Accounting Standards Issued But Not Yet Adopted Intangibles — In August 2018, the FASB issued 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. The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by the amendments in this update. The amendments in this update are effective for interim and annual periods for the Company beginning on January 1, 2020, with early adoption permitted. The amendments in this update should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company is currently evaluating the potential effect of this new guidance on its financial statements. Retirement benefits — In August 2018, the FASB issued ASU 2018-14, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20). The amendments in this update remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures, and add disclosure requirements identified as relevant. The amendments in this update are effective for fiscal years ending after December 15, 2020 with early adoption permitted. The Company is currently evaluating the potential effect of this new guidance on its financial statements. Fair value measurements — In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820). The new guidance modifies disclosure requirements related to fair value measurement. The amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Implementation on a prospective or retrospective basis varies by specific disclosure requirement. Early adoption is permitted. The standard also allows for early adoption of any removed or modified disclosures upon issuance of this ASU while delaying adoption of the additional disclosures until their effective date. The Company is currently evaluating the potential effect of this new guidance on its financial statements.