RELATED PARTY TRANSACTIONS	12 Months Ended
Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	RELATED PARTY TRANSACTIONS The Corporation sells its products to Dow to simplify the customer interface process. Products are sold to and purchased from Dow at market-based prices in accordance with the terms of Dow’s intercompany pricing policies. After each quarter, the Corporation and Dow analyze the pricing used for the sales in that quarter and reach agreement on any necessary adjustments, at which point the prices are final. The Corporation also procures certain commodities and raw materials through a Dow subsidiary and pays a commission to that Dow subsidiary based on the volume and type of commodities and raw materials purchased. The commission expense was included in "Sundry income (expense) - net" in the consolidated statements of income. Purchases from that Dow subsidiary were approximately $1.7 billion in 2017, $1.4 billion in 2016 and $1.7 billion in 2015. The Corporation has a master services agreement with Dow whereby Dow provides services including, but not limited to, accounting, legal, treasury (investments, cash management, risk management, insurance), procurement, human resources, environmental, health and safety, and business management for UCC. Under the master services agreement with Dow, general administrative and overhead type services that Dow routinely allocates to various businesses are charged to UCC. The master services agreement cost allocation basis is headcount and includes a 10 percent service fee. This agreement resulted in expense of $33 million in 2017, $27 million in 2016 and $30 million in 2015 for general administrative and overhead type services and the 10 percent service fee, and was included in "Sundry income (expense) - net" in the consolidated statements of income. The remaining activity-based costs were approximately $78 million in 2017, $58 million in 2016 and $63 million in 2015 and were included in "Cost of sales" in the consolidated statements of income. Management believes the method used for determining expenses charged by Dow is reasonable. Dow provides these services by leveraging its centralized functional service centers to provide services at a cost that management believes provides an advantage to the Corporation. The monitoring and execution of risk management policies related to interest rate and foreign currency risks, which are based on Dow’s risk management philosophy, are provided as a service to UCC. As part of Dow’s cash management process, UCC is a party to revolving loans with Dow that have interest rates based on LIBOR (London Interbank Offered Rate) with varying maturities. At December 31, 2017, the Corporation had a note receivable of $1.2 billion ($1.4 billion at December 31, 2016) from Dow under a revolving loan agreement. The Corporation may draw from this note receivable in support of its daily working capital requirements and, as such, the net effect of cash inflows and outflows under this revolving loan agreement is presented in the consolidated statements of cash flows as an operating activity. The Corporation also has a separate revolving credit agreement with Dow that allows the Corporation to borrow or obtain credit enhancements up to an aggregate of $1 billion that matures on December 30, 2018. Dow may demand repayment with a 30-day written notice to the Corporation, subject to certain restrictions. A related collateral agreement provides for the replacement of certain existing pledged assets, primarily equity interests in various subsidiaries and joint ventures, with cash collateral. At December 31, 2017, $949 million ($947 million at December 31, 2016) was available under the revolving credit agreement. The cash collateral was reported as "Noncurrent receivables from related companies" in the consolidated balance sheets. On a quarterly basis, the Corporation's Board of Directors reviews and determines if there will be a dividend distribution to its parent company and sole shareholder, Dow. The Board takes into consideration the level of earnings and cash flows, among other factors, in determining the amount of the dividend distribution. In 2017, the Corporation declared and paid dividends totaling $603 million to Dow. In 2016, the Corporation declared and paid dividends totaling $500 million to Dow. In accordance with the Tax Sharing Agreement between the Corporation and Dow, the Corporation makes payments to Dow to cover the Corporation's estimated federal tax liability; payments were $294 million in 2017, $415 million in 2016 and $310 million in 2015.

RELATED PARTY TRANSACTIONS

The Corporation sells its products to Dow to simplify the customer interface process. Products are sold to and purchased from Dow at market-based prices in accordance with the terms of Dow’s intercompany pricing policies. After each quarter, the Corporation and Dow analyze the pricing used for the sales in that quarter and reach agreement on any necessary adjustments, at which point the prices are final. The Corporation also procures certain commodities and raw materials through a Dow subsidiary and pays a commission to that Dow subsidiary based on the volume and type of commodities and raw materials purchased. The commission expense was included in "Sundry income (expense) - net" in the consolidated statements of income. Purchases from that Dow subsidiary were approximately $1.7 billion in 2017, $1.4 billion in 2016 and $1.7 billion in 2015.

The Corporation has a master services agreement with Dow whereby Dow provides services including, but not limited to, accounting, legal, treasury (investments, cash management, risk management, insurance), procurement, human resources, environmental, health and safety, and business management for UCC. Under the master services agreement with Dow, general administrative and overhead type services that Dow routinely allocates to various businesses are charged to UCC. The master services agreement cost allocation basis is headcount and includes a 10 percent service fee. This agreement resulted in expense of $33 million in 2017, $27 million in 2016 and $30 million in 2015 for general administrative and overhead type services and the 10 percent service fee, and was included in "Sundry income (expense) - net" in the consolidated statements of income. The remaining activity-based costs were approximately $78 million in 2017, $58 million in 2016 and $63 million in 2015 and were included in "Cost of sales" in the consolidated statements of income.

Management believes the method used for determining expenses charged by Dow is reasonable. Dow provides these services by leveraging its centralized functional service centers to provide services at a cost that management believes provides an advantage to the Corporation.

The monitoring and execution of risk management policies related to interest rate and foreign currency risks, which are based on Dow’s risk management philosophy, are provided as a service to UCC.

As part of Dow’s cash management process, UCC is a party to revolving loans with Dow that have interest rates based on LIBOR (London Interbank Offered Rate) with varying maturities. At December 31, 2017, the Corporation had a note receivable of $1.2 billion ($1.4 billion at December 31, 2016) from Dow under a revolving loan agreement. The Corporation may draw from this note receivable in support of its daily working capital requirements and, as such, the net effect of cash inflows and outflows under this revolving loan agreement is presented in the consolidated statements of cash flows as an operating activity.

The Corporation also has a separate revolving credit agreement with Dow that allows the Corporation to borrow or obtain credit enhancements up to an aggregate of $1 billion that matures on December 30, 2018. Dow may demand repayment with a 30-day written notice to the Corporation, subject to certain restrictions. A related collateral agreement provides for the replacement of certain existing pledged assets, primarily equity interests in various subsidiaries and joint ventures, with cash collateral. At December 31, 2017, $949 million ($947 million at December 31, 2016) was available under the revolving credit agreement. The cash collateral was reported as "Noncurrent receivables from related companies" in the consolidated balance sheets.

On a quarterly basis, the Corporation's Board of Directors reviews and determines if there will be a dividend distribution to its parent company and sole shareholder, Dow. The Board takes into consideration the level of earnings and cash flows, among other factors, in determining the amount of the dividend distribution. In 2017, the Corporation declared and paid dividends totaling $603 million to Dow. In 2016, the Corporation declared and paid dividends totaling $500 million to Dow.

In accordance with the Tax Sharing Agreement between the Corporation and Dow, the Corporation makes payments to Dow to cover the Corporation's estimated federal tax liability; payments were $294 million in 2017, $415 million in 2016 and $310 million in 2015.