Cover Page - shares	3 Months Ended
	Mar. 31, 2021	May 03, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-12387
Entity Registrant Name	TENNECO INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	76-0515284
Entity Address, Address Line One	500 North Field Drive
Entity Address, City or Town	Lake Forest
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60045
City Area Code	847
Local Phone Number	482-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		81,968,916
Entity Central Index Key	0001024725
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Class A
Document Information [Line Items]
Title of 12(b) Security	Class A Voting Common Stock, par value $0.01 per share
Trading Symbol	TEN
Security Exchange Name	NYSE
Preferred Stock Purchase Rights
Document Information [Line Items]
Title of 12(b) Security	Preferred Stock Purchase Rights
Security Exchange Name	NYSE
No Trading Symbol Flag	true