SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation (Policies)	3 Months Ended
Mar. 31, 2026
Basis of Presentation [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared by Eastman Chemical Company ("Eastman" or the "Company") in accordance and consistent with the accounting policies stated in the Company's 2025 Annual Report on Form 10-K, and should be read in conjunction with the consolidated financial statements in Part II, Item 8 of that report, with the exception of recently adopted accounting standards noted below. The December 31, 2025 financial position data included herein was derived from the consolidated financial statements included in the 2025 Annual Report on Form 10-K but does not include all disclosures required by accounting principles generally accepted in the United States ("GAAP"). In the opinion of management, the unaudited consolidated financial statements include all normal recurring adjustments necessary for the fair presentation of the interim financial information in conformity with GAAP. These statements contain some amounts that are based upon management estimates and judgments. Future actual results could differ from such current estimates and judgments. The unaudited consolidated financial statements include assets, liabilities, sales revenue, and expenses of all majority-owned subsidiaries and joint ventures in which a controlling interest is maintained. Eastman accounts for other joint ventures and investments in minority-owned companies where it exercises significant influence on an equity basis. Intercompany transactions and balances are eliminated in consolidation.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Standards Accounting Standards Update ("ASU") 2025-05 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets: On January 1, 2026, Eastman adopted this update which addresses the application of Topic 326 to current accounts receivable and current contract assets arising from transactions accounted for under Topic 606, Revenue from Contracts with Customers. The update provides a practical expedient permitting entities, when estimating expected credit losses for those balances, to assume that current conditions at the balance sheet date do not change over the remaining life of the asset. The Company elected the practical expedient upon adoption. The adoption did not have an impact on the Company's financial statements and related disclosures. Accounting Standards Issued But Not Adopted as of March 31, 2026 ASU 2024-03 Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses: The Financial Accounting Standards Board ("FASB") issued this update in November 2024, which requires public companies to provide additional disclosure of certain income statement expense line items. This guidance is intended to improve transparency around the nature of expenses and their impact on financial performance. The ASU is effective for fiscal periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption is permitted, and the transition method is prospective, with the option for retrospective application. Management is currently evaluating the impact of the changes required by the new standard on the Company's financial statements and related disclosures. ASU 2025-06 Intangibles Goodwill and Other Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software: The FASB issued this update in September 2025, which removes prescriptive development stages and establishes a probable-to-complete recognition threshold under which capitalization of software development costs begins when management has authorized and committed to funding the project and it is probable the project will be completed and used as intended. The ASU is effective for fiscal periods beginning after December 15, 2027, including interim periods within those years, with early adoption permitted. The update permits prospective application. Management is currently evaluating the impact of the changes required by the new standard on the Company's financial statements and related disclosures. ASU 2025-10 Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities: The FASB issued this update in December 2025, which establishes authoritative guidance on the accounting for government grants, including grants related to an asset and grants related to income. The amendments, largely aligned with International Accounting Standards 20 Accounting for Government Grants and Disclosure of Government Assistance ("IAS 20"), require that a government grant not be recognized until it is probable the Company will comply with the conditions attached to the grant and that the grant will be received. The amendments further codify specific recognition approaches for asset-related grants and for income-related grants, with presentation as income or deducted from the related expense. The ASU is effective for fiscal periods beginning after December 15, 2028, including interim periods within those years, with early adoption permitted. The transition method may be modified prospective, modified retrospective, or retrospective. Management is currently evaluating the impact of the changes required by the new standard on the Company's financial statements and related disclosures.
Change in Laws and Regulations	Working Capital Management and Off-Balance Sheet Arrangements The Company engages in off-balance sheet, uncommitted accounts receivable factoring programs as a routine part of its ordinary business operations. Through these programs, entire invoices may be sold to third-party financial institutions, the vast majority of which are without recourse. Under these agreements, the Company sells the invoices at face value, less a transaction fee, which substantially equals the carrying value and fair value with no gain or loss recognized, and no credit loss exposure is retained. Available capacity under these programs, which the Company uses as a routine source of working capital funding, is dependent on the level of accounts receivable eligible to be sold and the financial institutions' willingness to purchase such receivables. In addition, certain programs also require that the Company continue to service, administer, and collect the sold accounts receivable at market rates. The total amounts sold under the program in first quarter 2026 and 2025 were $648 million and $676 million, respectively. The Company works with suppliers to optimize payment terms and conditions on accounts payable to enhance the timing of working capital and cash flows. As part of its supplier financing programs, suppliers may voluntarily sell receivables due from Eastman to a participating financial institution. Eastman's responsibility is limited to making payments on the terms originally negotiated with suppliers, and the range of payment terms Eastman negotiates with suppliers is consistent regardless of whether a supplier participates in the program. Either Eastman or a participating financial institution may terminate a supplier finance program upon 90 days' notice. Within these programs, the Company maintains a structured payables program that utilizes a payables processing arrangement with a financial institution to support the processing and settlement of freight and logistics invoices, whereby the financial institution remits payments to certain freight service providers based on invoices approved by the Company, and the Company reimburses the financial institution. The Company pays fixed per‑transaction fees for the invoice processing and payment services for the structured payables program. Confirmed obligations in these programs of $136 million and $110 million at March 31, 2026 and December 31, 2025, respectively, are included in "Payables and other current liabilities" on the Unaudited Consolidated Statements of Financial Position. Government Grants On May 29, 2025, the U.S. Department of Energy ("DOE") terminated an award related to the Company's Polyethylene Terephthalate Recycling Decarbonization Project in Longview, Texas. The Company continues to record reimbursements for amounts incurred prior to the date of the award termination and for which the Company is contractually entitled under an assistance agreement with the DOE. The Company received $3 million in reimbursements from the DOE during first quarter 2026 related to reimbursement requests from the prior year. All requested reimbursements have been received as of March 31, 2026. While waiting for a decision on reinstatement of the award, the Company is actively evaluating the impact of the termination on the project's scope, timeline, and use of associated assets. The Company has prepared and submitted a settlement proposal in the event reinstatement is not obtained. For additional government grant information, see Note 1, "Significant Accounting Policies", to the consolidated financial statements in Part II, Item 8 of the Company's 2025 Annual Report on Form 10-K. Change in Laws and Regulations Eastman recognizes the financial statement effects of changes in laws or regulations in the period in which the Company obtains a legal right to the related asset or incurs a legal obligation for the related liability. On February 20, 2026, the Supreme Court ruled that the tariffs imposed under the International Emergency Economic Powers Act ("IEEPA") were not sufficiently authorized and deemed invalid. Further, on March 4, 2026, the Court of International Trade ruled that U.S. Customs and Border Protection must refund IEEPA tariffs that were collected. As a result of these court rulings establishing the Company's legal right to a refund of IEEPA tariffs, the Company recognized a $22 million benefit in "Cost of sales" in the Unaudited Consolidated Statements of Earnings, Comprehensive Income and Retained Earnings and a $22 million increase in "Miscellaneous receivables" in the Unaudited Consolidated Statements of Financial Position. On April 20, 2026, all applicable IEEPA entries were submitted and are currently pending refund processing.

SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation (Policies)

3 Months Ended

Mar. 31, 2026

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation

The accompanying unaudited consolidated financial statements have been prepared by Eastman Chemical Company ("Eastman" or the "Company") in accordance and consistent with the accounting policies stated in the Company's 2025 Annual Report on Form 10-K, and should be read in conjunction with the consolidated financial statements in Part II, Item 8 of that report, with the exception of recently adopted accounting standards noted below. The December 31, 2025 financial position data included herein was derived from the consolidated financial statements included in the 2025 Annual Report on Form 10-K but does not include all disclosures required by accounting principles generally accepted in the United States ("GAAP").

In the opinion of management, the unaudited consolidated financial statements include all normal recurring adjustments necessary for the fair presentation of the interim financial information in conformity with GAAP. These statements contain some amounts that are based upon management estimates and judgments. Future actual results could differ from such current estimates and judgments. The unaudited consolidated financial statements include assets, liabilities, sales revenue, and expenses of all majority-owned subsidiaries and joint ventures in which a controlling interest is maintained. Eastman accounts for other joint ventures and investments in minority-owned companies where it exercises significant influence on an equity basis. Intercompany transactions and balances are eliminated in consolidation.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted Accounting Standards

Accounting Standards Update ("ASU") 2025-05 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets: On January 1, 2026, Eastman adopted this update which addresses the application of Topic 326 to current accounts receivable and current contract assets arising from transactions accounted for under Topic 606, Revenue from Contracts with Customers. The update provides a practical expedient permitting entities, when estimating expected credit losses for those balances, to assume that current conditions at the balance sheet date do not change over the remaining life of the asset. The Company elected the practical expedient upon adoption. The adoption did not have an impact on the Company's financial statements and related disclosures.

Accounting Standards Issued But Not Adopted as of March 31, 2026

ASU 2024-03 Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses: The Financial Accounting Standards Board ("FASB") issued this update in November 2024, which requires public companies to provide additional disclosure of certain income statement expense line items. This guidance is intended to improve transparency around the nature of expenses and their impact on financial performance. The ASU is effective for fiscal periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption is permitted, and the transition method is prospective, with the option for retrospective application. Management is currently evaluating the impact of the changes required by the new standard on the Company's financial statements and related disclosures.

ASU 2025-06 Intangibles Goodwill and Other Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software: The FASB issued this update in September 2025, which removes prescriptive development stages and establishes a probable-to-complete recognition threshold under which capitalization of software development costs begins when management has authorized and committed to funding the project and it is probable the project will be completed and used as intended. The ASU is effective for fiscal periods beginning after December 15, 2027, including interim periods within those years, with early adoption permitted. The update permits prospective application. Management is currently evaluating the impact of the changes required by the new standard on the Company's financial statements and related disclosures.

ASU 2025-10 Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities: The FASB issued this update in December 2025, which establishes authoritative guidance on the accounting for government grants, including grants related to an asset and grants related to income. The amendments, largely aligned with International Accounting Standards 20 Accounting for Government Grants and Disclosure of Government Assistance ("IAS 20"), require that a government grant not be recognized until it is probable the Company will comply with the conditions attached to the grant and that the grant will be received. The amendments further codify specific recognition approaches for asset-related grants and for income-related grants, with presentation as income or deducted from the related expense. The ASU is effective for fiscal periods beginning after December 15, 2028, including interim periods within those years, with early adoption permitted. The transition method may be modified prospective, modified retrospective, or retrospective. Management is currently evaluating the impact of the changes required by the new standard on the Company's financial statements and related disclosures.

Change in Laws and Regulations

Working Capital Management and Off-Balance Sheet Arrangements

The Company engages in off-balance sheet, uncommitted accounts receivable factoring programs as a routine part of its ordinary business operations. Through these programs, entire invoices may be sold to third-party financial institutions, the vast majority of which are without recourse. Under these agreements, the Company sells the invoices at face value, less a transaction fee, which substantially equals the carrying value and fair value with no gain or loss recognized, and no credit loss exposure is retained. Available capacity under these programs, which the Company uses as a routine source of working capital funding, is dependent on the level of accounts receivable eligible to be sold and the financial institutions' willingness to purchase such receivables. In addition, certain programs also require that the Company continue to service, administer, and collect the sold accounts receivable at market rates. The total amounts sold under the program in first quarter 2026 and 2025 were $648 million and $676 million, respectively.

The Company works with suppliers to optimize payment terms and conditions on accounts payable to enhance the timing of working capital and cash flows. As part of its supplier financing programs, suppliers may voluntarily sell receivables due from Eastman to a participating financial institution. Eastman's responsibility is limited to making payments on the terms originally negotiated with suppliers, and the range of payment terms Eastman negotiates with suppliers is consistent regardless of whether a supplier participates in the program. Either Eastman or a participating financial institution may terminate a supplier finance program upon 90 days' notice. Within these programs, the Company maintains a structured payables program that utilizes a payables processing arrangement with a financial institution to support the processing and settlement of freight and logistics invoices, whereby the financial institution remits payments to certain freight service providers based on invoices approved by the Company, and the Company reimburses the financial institution. The Company pays fixed per‑transaction fees for the invoice processing and payment services for the structured payables program.

Confirmed obligations in these programs of $136 million and $110 million at March 31, 2026 and December 31, 2025, respectively, are included in "Payables and other current liabilities" on the Unaudited Consolidated Statements of Financial Position.

Government Grants

On May 29, 2025, the U.S. Department of Energy ("DOE") terminated an award related to the Company's Polyethylene Terephthalate Recycling Decarbonization Project in Longview, Texas. The Company continues to record reimbursements for amounts incurred prior to the date of the award termination and for which the Company is contractually entitled under an assistance agreement with the DOE. The Company received $3 million in reimbursements from the DOE during first quarter 2026 related to reimbursement requests from the prior year. All requested reimbursements have been received as of March 31, 2026. While waiting for a decision on reinstatement of the award, the Company is actively evaluating the impact of the termination on the project's scope, timeline, and use of associated assets. The Company has prepared and submitted a settlement proposal in the event reinstatement is not obtained.

For additional government grant information, see Note 1, "Significant Accounting Policies", to the consolidated financial statements in Part II, Item 8 of the Company's 2025 Annual Report on Form 10-K.

Change in Laws and Regulations

Eastman recognizes the financial statement effects of changes in laws or regulations in the period in which the Company obtains a legal right to the related asset or incurs a legal obligation for the related liability. On February 20, 2026, the Supreme Court ruled that the tariffs imposed under the International Emergency Economic Powers Act ("IEEPA") were not sufficiently authorized and deemed invalid. Further, on March 4, 2026, the Court of International Trade ruled that U.S. Customs and Border Protection must refund IEEPA tariffs that were collected. As a result of these court rulings establishing the Company's legal right to a refund of IEEPA tariffs, the Company recognized a $22 million benefit in "Cost of sales" in the Unaudited Consolidated Statements of Earnings, Comprehensive Income and Retained Earnings and a $22 million increase in "Miscellaneous receivables" in the Unaudited Consolidated Statements of Financial Position. On April 20, 2026, all applicable IEEPA entries were submitted and are currently pending refund processing.