CONSOLIDATED STATEMENTS OF EARNINGS, COMPREHENSIVE INCOME AND RETAINED EARNINGS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Sales	$ 8,752	$ 9,382	$ 9,210
Cost of sales	6,908	7,092	7,149
Gross profit	1,844	2,290	2,061
Selling, general and administrative expenses	658	736	727
Research and development expenses	255	250	239
Asset impairments, restructuring, and other charges, net	96	51	37
Other components of post-employment (benefit) cost, net	(25)	(72)	41
Other (income) charges, net	84	47	38
Gain on divested business	0	0	(323)
Earnings before interest and taxes	776	1,278	1,302
Net interest expense	208	200	215
Earnings before income taxes	568	1,078	1,087
Provision for income taxes	93	170	191
Net earnings	475	908	896
Less: Net earnings attributable to noncontrolling interest	1	3	2
Net earnings attributable to Eastman	$ 474	$ 905	$ 894
Basic earnings per share attributable to Eastman
Basic earnings per share attributable to Eastman	$ 4.14	$ 7.75	$ 7.54
Diluted earnings per share attributable to Eastman
Diluted earnings per share attributable to Eastman	$ 4.10	$ 7.67	$ 7.49
Comprehensive Income
Net earnings including noncontrolling interest	$ 475	$ 908	$ 896
Other comprehensive income (loss), net of tax:
Change in cumulative translation adjustment	34	(20)	(67)
Defined benefit pension and other postretirement benefit plans [Abstract]
Prior service credit arising during the period	157	0	0
Amortization of unrecognized prior service credits included in net periodic costs	(8)	(8)	(21)
Derivatives and hedging [Abstract]
Unrealized gain (loss) during period	(44)	18	(27)
Reclassification adjustment for (gains) losses included in net income, net	15	15	1
Total other comprehensive income (loss), net of tax	154	5	(114)
Comprehensive income including noncontrolling interest	629	913	782
Less: Net earnings attributable to noncontrolling interest	1	3	2
Comprehensive income attributable to Eastman	628	910	780
Retained Earnings
Retained earnings at beginning of period	10,013	9,490	8,973
Net earnings attributable to Eastman	474	905	894
Cash dividends declared	(382)	(382)	(377)
Retained earnings at end of period	$ 10,105	$ 10,013	$ 9,490