Organization, Consolidation and Presentation of Financial Statements	9 Months Ended
Sep. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	CONSOLIDATED FINANCIAL STATEMENTS Basis of Presentation The unaudited interim consolidated financial statements of Union Carbide Corporation and its subsidiaries (the "Corporation" or "UCC") were prepared in accordance with accounting principles generally accepted in the United States of America and reflect all adjustments (including normal recurring accruals) which, in the opinion of management, are considered necessary for the fair presentation of the results for the periods presented. These statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2024 ("2024 10-K"). The Corporation is a wholly owned subsidiary of The Dow Chemical Company ("TDCC"). In accordance with the accounting guidance for earnings per share, the presentation of earnings per share is not required in financial statements of wholly owned subsidiaries. TDCC conducts its worldwide operations through global businesses and the Corporation's business activities comprise components of TDCC's global businesses rather than stand-alone operations. Further, the Corporation sells substantially all of its products to TDCC in order to simplify the customer interface process. The Corporation's Board of Directors, acting pursuant to the authority delegated to it by TDCC, functions as the Corporation's chief operating decision maker ("CODM") to assess UCC's results and allocate resources for its operations. The Corporation's results are reported as a single operating segment as the consolidated statements of income are presented to the CODM without further disaggregation. Intercompany transactions and balances are eliminated in consolidation. Transactions with the Corporation’s parent company, TDCC, and other subsidiaries of TDCC, have been reflected as related company transactions in the consolidated financial statements. See Note 12 for additional information.

Organization, Consolidation and Presentation of Financial Statements

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

CONSOLIDATED FINANCIAL STATEMENTS

Basis of Presentation

The unaudited interim consolidated financial statements of Union Carbide Corporation and its subsidiaries (the "Corporation" or "UCC") were prepared in accordance with accounting principles generally accepted in the United States of America and reflect all adjustments (including normal recurring accruals) which, in the opinion of management, are considered necessary for the fair presentation of the results for the periods presented. These statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2024 ("2024 10-K").

The Corporation is a wholly owned subsidiary of The Dow Chemical Company ("TDCC"). In accordance with the accounting guidance for earnings per share, the presentation of earnings per share is not required in financial statements of wholly owned subsidiaries.

TDCC conducts its worldwide operations through global businesses and the Corporation's business activities comprise components of TDCC's global businesses rather than stand-alone operations. Further, the Corporation sells substantially all of its products to TDCC in order to simplify the customer interface process. The Corporation's Board of Directors, acting pursuant to the authority delegated to it by TDCC, functions as the Corporation's chief operating decision maker ("CODM") to assess UCC's results and allocate resources for its operations. The Corporation's results are reported as a single operating segment as the consolidated statements of income are presented to the CODM without further disaggregation.

Intercompany transactions and balances are eliminated in consolidation. Transactions with the Corporation’s parent company, TDCC, and other subsidiaries of TDCC, have been reflected as related company transactions in the consolidated financial statements. See Note 12 for additional information.