CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues
Net sales and operating revenues	$ 4,332	$ 4,256	$ 13,646	$ 10,729
Costs and expenses
Cost of sales (exclusive of depreciation and amortization)	3,776	3,610	11,810	9,447
Selling, general, and administrative	240	214	764	658
Depreciation and amortization	147	151	447	481
Engineering, research, and development	71	67	216	199
Restructuring charges, net and asset impairments	(4)	17	48	622
Goodwill and intangible impairment charges	0	0	0	383
Costs and expenses	4,230	4,059	13,285	11,790
Other income (expense)
Non-service pension and postretirement benefit (costs) credits	4	18	10	20
Equity in earnings (losses) of nonconsolidated affiliates, net of tax	10	9	47	26
Gain (loss) on extinguishment of debt	0	0	8	0
Other income (expense), net	9	12	30	31
Total other expense (income)	23	39	95	77
Earnings (loss) before interest expense, income taxes, and noncontrolling interests	125	236	456	(984)
Interest expense	(66)	(68)	(205)	(209)
Earnings (loss) before income taxes and noncontrolling interests	59	168	251	(1,193)
Income tax (expense) benefit	(34)	(648)	(122)	(453)
Net income (loss)	25	(480)	129	(1,646)
Less: Net income (loss) attributable to noncontrolling interests	10	19	59	42
Net income (loss) attributable to Tenneco Inc.	$ 15	$ (499)	$ 70	$ (1,688)
Basic earnings (loss) per share:
Earnings (loss) per share (in dollars per share)	$ 0.17	$ (6.12)	$ 0.85	$ (20.75)
Weighted average shares outstanding (in shares)	82,310,645	81,456,821	82,171,755	81,325,385
Diluted earnings (loss) per share:
Earnings (loss) per share (in dollars per share)	$ 0.17	$ (6.12)	$ 0.83	$ (20.75)
Weighted average shares outstanding (in shares)	84,103,606	81,456,821	83,475,736	81,325,385