Pending Acquisition of Federal-Mogul	6 Months Ended
Jun. 30, 2018
Business Combinations [Abstract]
Pending Acquisition of Federal-Mogul	Pending Acquisition of Federal-Mogul On April 10, 2018, Tenneco entered into a Membership Interest Purchase Agreement (the "Purchase Agreement") with Federal-Mogul LLC ("Federal-Mogul"), American Entertainment Properties Corp. ("AEP"), and Icahn Enterprises L.P. ("IEP"), pursuant to which Tenneco will acquire Federal-Mogul (the “Acquisition”). Subject to the terms and conditions of the Purchase Agreement, Tenneco will (i) pay to AEP an aggregate amount in cash equal to $800 million (the “Cash Consideration”) and (ii) issue and deliver to AEP an aggregate of 29,444,846 shares (the “Stock Consideration”) of Tenneco's common stock, subject to reduction if Tenneco undertakes a primary offering of common stock prior to the closing of the Acquisition described below, which shall be comprised of: (a) a number of shares of common stock (to be reclassified as Class A Voting Common Stock, par value $0.01, at the closing of the Acquisition (“Class A Common Stock”)) equal to 9.9% of the aggregate number of shares of Class A Common Stock issued and outstanding as of immediately following the closing of the Acquisition, and (b) the balance in shares of newly created Class B Non-Voting Common Stock, par value $0.01 (“Class B Common Stock”). Until the date that is ten business days prior to the anticipated closing date of the Acquisition, Tenneco may elect to conduct an offering of its common stock in order to raise funds to increase the Cash Consideration. Such offering may include up to 7,315,490 shares of common stock that would otherwise have been issued to AEP in connection with the Acquisition. Each share sold in such an offering will decrease the number of shares of common stock issuable to AEP by one share, so the total number of shares of common stock to be issued in connection with the Acquisition will not change if Tenneco undertakes such an offering. The completion of the Acquisition is subject to certain customary closing conditions and the Purchase Agreement contains customary representations, warranties and covenants by each party that are subject, in some cases, to specified exceptions and qualifications contained in the Purchase Agreement. Following the closing of the Acquisition, Tenneco has agreed to use its reasonable best efforts to pursue the separation of the combined company’s powertrain technology business and its aftermarket & ride performance business into two separate, publicly traded companies in a spin-off transaction that is expected to be treated as a tax-free reorganization for U.S. federal income tax purposes (the "Spin-off" and, together with the Acquisition, the "Transaction"). Advisory costs associated with the pending acquisition were $18 million and $31 million for the three and six month periods ended June 30, 2018, respectively, and have been recognized as a component of selling, general and administrative expenses in the condensed consolidated statements of income (loss).

Pending Acquisition of Federal-Mogul

On April 10, 2018, Tenneco entered into a Membership Interest Purchase Agreement (the "Purchase Agreement") with Federal-Mogul LLC ("Federal-Mogul"), American Entertainment Properties Corp. ("AEP"), and Icahn Enterprises L.P. ("IEP"), pursuant to which Tenneco will acquire Federal-Mogul (the “Acquisition”).

Subject to the terms and conditions of the Purchase Agreement, Tenneco will (i) pay to AEP an aggregate amount in cash equal to $800 million (the “Cash Consideration”) and (ii) issue and deliver to AEP an aggregate of 29,444,846 shares (the “Stock Consideration”) of Tenneco's common stock, subject to reduction if Tenneco undertakes a primary offering of common stock prior to the closing of the Acquisition described below, which shall be comprised of: (a) a number of shares of common stock (to be reclassified as Class A Voting Common Stock, par value $0.01, at the closing of the Acquisition (“Class A Common Stock”)) equal to 9.9% of the aggregate number of shares of Class A Common Stock issued and outstanding as of immediately following the closing of the Acquisition, and (b) the balance in shares of newly created Class B Non-Voting Common Stock, par value $0.01 (“Class B Common Stock”).

Until the date that is ten business days prior to the anticipated closing date of the Acquisition, Tenneco may elect to conduct an offering of its common stock in order to raise funds to increase the Cash Consideration. Such offering may include up to 7,315,490 shares of common stock that would otherwise have been issued to AEP in connection with the Acquisition. Each share sold in such an offering will decrease the number of shares of common stock issuable to AEP by one share, so the total number of shares of common stock to be issued in connection with the Acquisition will not change if Tenneco undertakes such an offering.

The completion of the Acquisition is subject to certain customary closing conditions and the Purchase Agreement contains customary representations, warranties and covenants by each party that are subject, in some cases, to specified exceptions and qualifications contained in the Purchase Agreement.

Following the closing of the Acquisition, Tenneco has agreed to use its reasonable best efforts to pursue the separation of the combined company’s powertrain technology business and its aftermarket & ride performance business into two separate, publicly traded companies in a spin-off transaction that is expected to be treated as a tax-free reorganization for U.S. federal income tax purposes (the "Spin-off" and, together with the Acquisition, the "Transaction").

Advisory costs associated with the pending acquisition were $18 million and $31 million for the three and six month periods ended June 30, 2018, respectively, and have been recognized as a component of selling, general and administrative expenses in the condensed consolidated statements of income (loss).