Union Carbide 10-K 5 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 05, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	1-1463
Entity Registrant Name	UNION CARBIDE CORPORATION
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	13-1421730
Entity Address, Address Line One	7501 State Highway 185 North
Entity Address, City or Town	Seadrift
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77983
City Area Code	361
Local Phone Number	553-2997
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		935.51
Entity Central Index Key	0000100790
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Public Float	$ 0
ICFR Auditor Attestation Flag	false

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net trade sales	$ 129	$ 138	$ 136
Net sales to related companies	3,574	4,239	5,310
Total net sales	3,703	4,377	5,446
Cost of sales	3,245	3,500	4,047
Research and development expenses	24	25	21
Selling, general and administrative expenses	9	4	6
Restructuring Charges	15	79	3
Integration and separation costs	0	2	3
Total sundry income (expense) - net	168	(82)	(62)
Interest Income, Other	12	36	28
Interest expense and amortization of debt discount	33	30	30
Income Before Income Taxes	557	691	1,302
Provision (Credit) for income taxes	130	64	247
Net Income Attributable to Union Carbide Corporation	$ 427	$ 627	$ 1,055

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income attributable to Union Carbide Corporation	$ 427	$ 627	$ 1,055
Other comprehensive income (loss), net of tax
Cumulative translation adjustments	1	1	2
Pension and other postretirement benefit plans	(106)	(105)	43
Net other comprehensive income	(105)	(104)	45
Comprehensive income attributable to Union Carbide Corporation	$ 322	$ 523	$ 1,100

UCC Consolidated Balance Sheet

UCC Consolidated Balance Sheet - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 11	$ 11
Trade (net of allowance for doubtful receivables 2020: $—; 2019: $—)	26	26
Related companies	698	658
Other	27	17
Income taxes receivable	337	337
Notes receivable from related companies	1,660	1,505
Inventories	223	247
Other current assets	17	20
Total current assets	2,999	2,821
Investments in related companies	237	238
Other investments	22	22
Noncurrent receivables	124	118
Noncurrent receivables from related companies	66	66
Total investments	449	444
Property	7,089	7,247
Less accumulated depreciation	5,824	5,878
Net property	1,265	1,369
Intangible assets (net of accumulated amortization 2020: $97; 2019: $90)	16	22
Operating lease, right-of-use asset	123	89
Deferred Tax Assets, Deferred Income	494	507
Deferred charges and other assets	29	26
Total other assets	662	644
Total Assets	5,375	5,278
Notes payable to related companies	33	32
Notes Payable to Bank	0	6
Long-term debt due within one year	2	1
Trade	229	218
Related companies	409	386
Other	28	10
Operating lease liabilities - current	19	16
Income taxes payable	23	25
Asbestos-related liabilities - current	85	105
Accrued and other current liabilities	139	126
Total current liabilities	967	925
Long-Term Debt	391	473
Pension and other postretirement benefits - noncurrent	1,340	1,154
Asbestos-related liabilities - noncurrent	1,013	1,060
Operating lease liabilities - noncurrent	105	74
Other noncurrent obligations	201	194
Total other noncurrent liabilities	2,659	2,482
Common stock (authorized: 1,000 shares of $0.01 par value each; issued: 935.51 shares)	0	0
Additional paid-in capital	141	141
Retained earnings	2,987	2,922
Accumulated other comprehensive loss	(1,770)	(1,665)
Union Carbide Corporation's stockholders' equity	1,358	1,398
Total Liabilities and Equity	$ 5,375	$ 5,278

Consolidated Balance Sheet Pare

Consolidated Balance Sheet Parentheticals - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss, Current	$ 0	$ 0
Finite-Lived Intangible Assets, Accumulated Amortization	$ 97	$ 90
Common stock, shares authorized (in shares)	1,000	1,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued (in shares)	935.51	935.51

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net income attributable to Union Carbide Corporation	$ 427	$ 627	$ 1,055
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	210	204	207
Provision (credit) for deferred income tax	46	(10)	35
Net (gain) loss on sales of property and investments	(271)	6	0
Restructuring and asset related charges - net	15	79	3
Net periodic pension benefit cost	56	52	43
Pension contributions	(2)	(2)	(42)
Gain (Loss) on Extinguishment of Debt	19	0	0
Changes in assets and liabilities:
Accounts and notes receivable	(6)	13	23
Related company receivables	(194)	105	(100)
Inventories	33	23	(26)
Accounts payable	28	(51)	(6)
Related company payables	24	(121)	(169)
Asbestos-related payments	(67)	(95)	(109)
Other assets and liabilities	(42)	(82)	(113)
Cash provided by operating activities	276	748	801
Investing Activities
Capital expenditures	(135)	(196)	(250)
Change in noncurrent receivable from related company	0	(13)	0
Proceeds from sales of property	330	21	0
Purchases of investments	0	0	(1)
Proceeds from sales of investments	0	4	3
Cash provided by (used for) investing activities	195	(184)	(248)
Financing Activities
Dividends paid to parent	(362)	(570)	(553)
Changes in short-term notes payable	(6)	5	1
Payments on long-term debt	(84)	(1)	(1)
Payments of Financing Costs	(19)	0	0
Cash used for financing activities	(471)	(566)	(553)
Summary
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	0	(2)	0
Cash and cash equivalents at beginning of year	11	13	13
Cash and cash equivalents at end of year	$ 11	$ 11	$ 13

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accum. Other Comp Loss
Beginning balance at Dec. 31, 2017			$ 138	$ 2,582	$ (1,352)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other			0
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement [Member]				254	(254)
Net income attributable to Union Carbide Corporation	$ 1,055			1,055
Dividends declared				(553)
Stockholders' Equity, Other				0
Other Comprehensive Income (Loss), Net of Tax	45				45
Ending balance at Dec. 31, 2018	1,915	$ 0	138	3,338	(1,561)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other			3
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement [Member]				0	0
Net income attributable to Union Carbide Corporation	627			627
Dividends declared				(1,042)
Stockholders' Equity, Other				(1)
Other Comprehensive Income (Loss), Net of Tax	(104)				(104)
Ending balance at Dec. 31, 2019	1,398	0	141	2,922	(1,665)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other			0
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement [Member]				0	0
Net income attributable to Union Carbide Corporation	427			427
Dividends declared				(362)
Stockholders' Equity, Other				0
Other Comprehensive Income (Loss), Net of Tax	(105)				(105)
Ending balance at Dec. 31, 2020	$ 1,358	$ 0	$ 141	$ 2,987	$ (1,770)

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation and Basis of Presentation Except as otherwise indicated by the context, the terms "Corporation" and "UCC" as used herein mean Union Carbide Corporation and its consolidated subsidiaries. The accompanying consolidated financial statements of the Corporation were prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and include the assets, liabilities, revenues and expenses of all majority-owned subsidiaries over which the Corporation exercises control and, when applicable, entities for which the Corporation has a controlling financial interest. Investments in nonconsolidated affiliates (20-50 percent owned companies, joint ventures and partnerships) are accounted for using the equity method. 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. The Corporation’s business activities comprise components of TDCC’s global businesses rather than stand-alone operations. Because there are no separate reportable business segments for UCC under the accounting guidance related to segment reporting and no detailed business information is provided to a chief operating decision maker regarding the Corporation’s stand-alone operations, the Corporation’s results are reported as a single operating segment. On April 1, 2019, DowDuPont Inc. (“DowDuPont” and effective June 3, 2019, n/k/a DuPont de Nemours, Inc.) completed the separation of its materials science business and Dow Inc. became the direct parent company of TDCC and its consolidated subsidiaries. The separation was contemplated by the merger of equals transaction effective August 31, 2017, under the Agreement and Plan of Merger, dated as of December 11, 2015, as amended on March 31, 2017. TDCC and E. I. du Pont de Nemours and Company and its consolidated subsidiaries ("Historical DuPont") each merged with subsidiaries of DowDuPont, and, as a result, TDCC and Historical DuPont became subsidiaries of DowDuPont (the “Merger”). Subsequent to the Merger, TDCC and Historical DuPont engaged in a series of internal reorganization and realignment steps to realign their businesses into three subgroups: agriculture, materials science and specialty products. Dow Inc. was formed as a wholly owned subsidiary of DowDuPont to serve as the holding company for the materials science business. UCC remains a wholly owned subsidiary of TDCC. See Note 3 for additional information. 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 19 for additional information. Use of Estimates in Financial Statement Preparation The preparation of financial statements in accordance with U.S. GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. The Corporation's consolidated financial statements include amounts that are based on management's best estimates and judgments. Actual results could differ from those estimates. Significant Accounting Policies Asbestos-Related Matters Accruals for asbestos-related matters, including defense and processing costs, are recorded based on an analysis of claim and resolution activity, defense spending and pending and future claims. These accruals are assessed at each balance sheet date to determine if the asbestos-related liability remains appropriate. Accruals for asbestos-related matters are included in the consolidated balance sheets in "Asbestos-related liabilities - current" and "Asbestos-related liabilities - noncurrent." See Note 14 for additional information. Legal Costs The Corporation expenses legal costs as incurred, with the exception of defense and processing costs associated with asbestos-related matters. Foreign Currency Translation While the Corporation's consolidated subsidiaries are primarily based in the United States, the Corporation has small subsidiaries in Asia Pacific and the rest of the world. For those subsidiaries, the local currency has been primarily used as the functional currency. Translation gains and losses of those operations that use local currency as the functional currency are included in the consolidated balance sheets in "Accumulated other comprehensive loss" ("AOCL"). Where the U.S. dollar is used as the functional currency, foreign currency translation gains and losses are reflected in income. Environmental Matters Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated based on current law and existing technologies. These accruals are adjusted periodically as assessment and remediation efforts progress or as additional technical or legal information becomes available. Accruals for environmental liabilities are included in the consolidated balance sheets in "Accrued and other current liabilities" and "Other noncurrent obligations" at undiscounted amounts. Accruals for related insurance or other third-party recoveries for environmental liabilities are recorded when it is probable that a recovery will be realized and are included in the consolidated balance sheets in "Accounts receivable - Other." Environmental costs are capitalized if the costs extend the life of the property, increase its capacity, and/or mitigate or prevent contamination from future operations. Environmental costs are also capitalized in recognition of legal asset retirement obligations resulting from the acquisition, construction and/or normal operation of a long-lived asset. Costs related to environmental contamination treatment and cleanup are charged to expense. Estimated future incremental operations, maintenance and management costs directly related to remediation are accrued when such costs are probable and reasonably estimable. Cash and Cash Equivalents Cash and cash equivalents include time deposits and investments with maturities of three months or less at the time of purchase. Financial Instruments The Corporation calculates the fair value of financial instruments using quoted market prices when available. When quoted market prices are not available for financial instruments, the Corporation uses standard pricing models with market-based inputs that take into account the present value of estimated future cash flows. Inventories Inventories are stated at the lower of cost or net realizable value. The method of determining cost for each subsidiary varies among last-in, first-out ("LIFO"); first-in, first-out ("FIFO"); and average cost, and is used consistently from year to year. The Corporation routinely exchanges and swaps raw materials and finished goods with other companies to reduce delivery time, freight and other transportation costs. These transactions are treated as non-monetary exchanges and are valued at cost. Property Land, buildings and equipment are carried at cost less accumulated depreciation. Property under finance lease agreements is carried at the present value of lease payments over the lease term less accumulated amortization. Depreciation is based on the estimated service lives of depreciable assets and is calculated using the straight-line method. Fully depreciated assets are retained in property and accumulated depreciation accounts until they are removed from service. In the case of disposals, assets and related accumulated depreciation are removed from the accounts, and the net amounts, less proceeds from disposal, are included in income. Impairment and Disposal of Long-Lived Assets The Corporation evaluates long-lived assets and certain identifiable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. When undiscounted future cash flows are not expected to be sufficient to recover an asset's carrying amount, the asset is written down to its fair value based on bids received from third parties or a discounted cash flow analysis based on market participant assumptions. Long-lived assets to be disposed of by sale, if material, are classified as held for sale and reported at the lower of carrying amount or fair value less cost to sell, and depreciation is ceased. Long-lived assets to be disposed of other than by sale are classified as held and used until they are disposed of and reported at the lower of carrying amount or fair value, and depreciation is recognized over the remaining useful life of the assets. Other Intangible Assets Finite-lived intangible assets, such as developed technology and software, are amortized over their estimated useful lives, generally on a straight-line basis for periods ranging primarily from three to twenty years. Asset Retirement Obligations The Corporation records asset retirement obligations as incurred and reasonably estimable, including obligations for which the timing and/or method of settlement are conditional on a future event that may or may not be within the control of the Corporation. The fair values of obligations are recorded as liabilities on a discounted basis and are accreted over time for the change in present value. Costs associated with the liabilities are capitalized and amortized over the estimated remaining useful life of the asset, generally for periods of 10 years or less. Investments in Related Companies Investments in related companies consist of the Corporation's ownership interests in TDCC subsidiaries located in the United States and Latin America. The Corporation accounts for these investments using the cost method as it does not have significant influence over the operating and financial policies of these related companies. Leases Effective January 1, 2019, UCC adopted Accounting Standards Update ("ASU") 2016-02, "Leases (Topic 842)," and the associated ASUs (collectively, "Topic 842"). The Corporation added the following significant accounting policy for leases as a result of the adoption of Topic 842: UCC determines whether a contract contains a lease at contract inception. A contract contains a lease if there is an identified asset and the Corporation has the right to control the asset. Operating lease right-of-use (“ROU”) assets represent UCC’s right to use an underlying asset for the lease term, and lease liabilities represent UCC’s obligation to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. UCC uses the incremental borrowing rate in determining the present value of lease payments, unless the implicit rate is readily determinable. If lease terms include options to extend or terminate the lease, the ROU asset and lease liability are measured based on the reasonably certain decision. Leases with a term of 12 months or less at the commencement date are not recognized on the balance sheet and are expensed as incurred. UCC has lease agreements with lease and non-lease components, which are accounted for as a single lease component for nearly all classes of leased assets for which UCC is the lessee. Additionally, for certain equipment leases, the portfolio approach is applied to account for the operating lease ROU assets and lease liabilities. In the consolidated statements of income, lease expense for operating lease payments is recognized on a straight-line basis over the lease term. For finance leases, interest expense is recognized on the lease liability and the ROU asset is amortized over the lease term. Some leasing arrangements require variable payments that are dependent upon usage or output, or may vary for other reasons, such as insurance or tax payments. Variable lease payments are recognized as incurred and are not presented as part of the ROU asset or lease liability. See Note 15 for additional information. Revenue Substantially all of the Corporation's revenues are generated by sales to TDCC. Revenue for product sales to related companies is recognized when the related company obtains control of the product, which occurs either at the time that production is complete or shipped free on board ("FOB") from UCC's manufacturing facility, in accordance with the sales agreement between the Corporation and TDCC. The Corporation recognizes revenue for product sales to trade customers when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Corporation expects to receive in exchange for those goods or services. To determine revenue recognition, the Corporation performs the following five steps: (1) identify the contract(s) with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) the entity satisfies a performance obligation. See Note 4 for additional information. Severance Costs Management routinely reviews its operations around the world in an effort to ensure competitiveness across its operations and geographic regions. When the reviews result in a workforce reduction related to the shutdown of facilities or other optimization activities, severance benefits are provided to employees primarily under ongoing benefit arrangements. These severance costs are accrued once management commits to a plan of termination and it becomes probable that employees will be entitled to benefits at amounts that can be reasonably estimated. Integration and Separation Costs The Corporation classifies expenses related to the Merger and separation as integration and separation costs. Merger and separation related costs include: post-Merger integration expenses and costs incurred for the separation of TDCC’s agriculture business, materials science business and specialty products business. Integration and separation costs primarily consist of financial advisor, information technology, legal, accounting, consulting and other professional advisory fees associated with preparation and execution of these activities. Integration and separation costs related to the Merger and separation were completed as of December 31, 2020. Income Taxes The Corporation accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities using enacted tax rates. The effect of a change in tax rates on deferred tax assets or liabilities is recognized in income in the period that includes the enactment date. The Corporation is included in the same consolidated federal income tax group and consolidated income tax return as TDCC. The Corporation accounts for its income taxes following the formula in the TDCC-UCC Tax Sharing Agreement used to compute the amount due to TDCC or UCC for UCC's share of taxable income and tax attributes on the consolidated income tax return. This method generally follows the separate return method. The amounts reported as income taxes payable or receivable represent the Corporation's payment obligation (or refundable amount) to TDCC based on a theoretical tax liability calculated on a separate return method. The Corporation recognizes the financial statement effects of an uncertain income tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. The Corporation accrues for non-income tax contingencies when it is probable that a liability to a taxing authority has been incurred and the amount of the contingency can be reasonably estimated. Provision is made for taxes on undistributed earnings of foreign subsidiaries and related companies to the extent that such earnings are not deemed to be permanently invested. Changes in Financial Statement Presentation Consolidated Statements of Income In 2019, the Corporation made a change to separately report "Interest income" which had previously been included in "Sundry income (expense) - net" in the consolidated statements of income. Consolidated Statements of Equity

RECENT ACCOUNTING GUIDANCE

RECENT ACCOUNTING GUIDANCE	12 Months Ended
	Dec. 31, 2020
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recent Accounting Guidance	RECENT ACCOUNTING GUIDANCE Recently Adopted Accounting Guidance In the third quarter of 2020, the Corporation adopted ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” The amendments provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The new standard is effective March 12, 2020 through December 31, 2022, with the adoption date dependent upon the Corporation’s election. The Corporation has elected to apply the optional expedients and exceptions provided by the new guidance as modifications are made to relevant contracts, hedging relationships and other transactions during the reference rate reform transition period. As the amendments are intended to ease the potential burden in accounting for, or recognizing the effects of, reference rate reform on financial reporting, the application of this guidance has not and will not have a material impact on the consolidated financial statements. Accounting Guidance Issued But Not Adopted at December 31, 2020 In December 2019, the Financial Accounting Standards Board issued ASU 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes." The amendments simplify the accounting for income taxes by removing certain exceptions to the general principles of Topic 740, "Income Taxes" and improve consistent application by clarifying and amending existing guidance. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption is permitted, with the amendments to be applied on a retrospective, modified retrospective or prospective basis, depending on the specific amendment. The Corporation will adopt the new guidance in the first quarter of 2021 and the adoption is not expected to have a material impact on the consolidated financial statements.

MERGER WITH HISTORICAL DUPONT A

MERGER WITH HISTORICAL DUPONT AND BUSINESS SEPARATION	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Separation from DowDuPont	BUSINESS SEPARATIONIn the first quarter of 2019, in anticipation of DowDuPont's intended separation of its materials science business, UCC's assets and liabilities aligned with TDCC's specialty products business were transferred to TDCC as part of the internal reorganization steps to align TDCC's specialty products business to DowDuPont. In order to align entity ownership under TDCC, UCC distributed shares and assets to TDCC through dividends or asset distributions. As a result, in February 2019, UCC issued to TDCC a dividend of 1,067 shares of common stock of Dow International Holdings Company (“DIHC”), a cost method investment. Prior to the distribution, UCC had an 11.9 percent ownership interest in DIHC with the other 88.1 percent owned by TDCC and its other wholly owned subsidiaries. After the dividend, UCC’s investment in DIHC was reduced to 4.7 percent and resulted in a reduction in "Investments in related companies" of $401 million. UCC also transferred, as an asset distribution, the assets and liabilities aligned with TDCC's specialty products business for an additional dividend of $71 million to TDCC. The results of these transactions are reflected in “Investments in related companies” and “Retained earnings” in the consolidated balance sheets. See Note 19 for additional information. The Corporation evaluated the impact of the specialty products product line transfer and determined it did not represent a strategic shift that had a major effect on the Corporation’s operations and financial results and did not qualify as an individually significant component of the Corporation. As a result, this transfer was not reported as discontinued operations.

REVENUE

REVENUE	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Substantially all of the Corporation's revenue is generated by sales to TDCC. Products are sold to and purchased from TDCC at prices determined in accordance with the terms of an agreement between UCC and TDCC. The Corporation's revenue related to sales of product was approximately 98 percent in 2020 (99 percent in 2019 and 2018); the remaining revenue primarily related to the licensing of patents and technology. The Corporation sells its products to TDCC to simplify the customer interface process. Substantially all product sale contracts are short-term in nature and have original expected durations of one year or less. Revenue from product sales is recognized when TDCC or the customer obtains control of the Corporation’s product, which occurs at a point in time, typically at the time production is complete or product is shipped FOB from UCC’s manufacturing facility for sales to TDCC, or upon shipment for sales to trade customers. The Corporation’s payment terms are on average 30 to 60 days after invoicing. All shipping and handling activities that occur after control transfers to the customer are considered fulfillment activities. Certain long-term contracts include a series of distinct goods that are delivered continuously to the customer through a pipeline. For these types of product sales, the Corporation invoices the customer in an amount that directly corresponds with the value to the customer of the Corporation’s performance to date. As a result, revenue is recognized based on the amount billable to the customer in accordance with the right to invoice practical expedient. The transaction price for product sales includes estimates for the most likely amount of consideration to which the Corporation will be entitled based on historical award experience and the Corporation’s best judgment at the time. Taxes collected and remitted to governmental authorities are excluded from the transaction price. For contracts with multiple performance obligations, the Corporation allocates the transaction price to each performance obligation on the basis of relative standalone selling price, which is based on the price charged to customers or estimated using the expected cost plus margin method. Revenue related to the initial licensing of patents and technology is recognized when the performance obligation is satisfied. Revenue related to sales-based royalties to which the Corporation expects to be entitled is estimated based on historical sales. The Corporation’s contract liabilities include payments received in advance of performance under long-term contracts for product sales and royalties with remaining contract terms that range up to 21 years. Amounts are recognized in revenue when the performance obligations for the contract are met. The Corporation has rights to additional consideration when product is delivered to the customer. The balance of contract liabilities was $40 million at December 31, 2020 ($41 million at December 31, 2019), of which $5 million ($4 million at December 31, 2019) was included in "Accrued and other current liabilities" and $35 million ($37 million at December 31, 2019) was included in "Other noncurrent obligations" in the consolidated balance sheets. The Corporation disaggregates its revenue from contracts with customers by type of customer (sales to related parties and sales to trade customers) as presented on the consolidated statements of income and believes this disaggregation best depicts the nature, amount, timing and uncertainty of its revenue and cash flows. Substantially all of the product sales are made to the Corporation's parent company, TDCC, and there are no unique economic factors that affect revenue recognition and cash flows associated with these product sales.

DIVESTITURE

DIVESTITURE	12 Months Ended
	Dec. 31, 2020
Discontinued Operations and Disposal Groups [Abstract]
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	DIVESTITURES Divestiture of Rail Infrastructure Operations and Assets On July 2, 2020, TDCC entered into a definitive agreement to sell its rail infrastructure operations and assets at certain sites in the U.S. and Canada to an affiliate of Watco Companies, L.L.C. ("Watco affiliate") and the transaction closed September 30, 2020. As part of this transaction, UCC sold its related operations and assets, including existing agreements to provide rail services to unrelated third parties, located at its sites in St. Charles, Louisiana ("St. Charles"), and Seadrift, Texas, with a net book value of $9 million, to the Watco affiliate. UCC retained ownership of the sites and underlying real property where the divested operations are located. UCC and the Watco affiliate entered into mutual long-term service agreements designed to ensure the continuation of rail services for UCC's existing operations at the impacted sites. The rail-service agreements include variable fees that have an initial term of 25 years. As part of the sale, UCC received proceeds of $95 million from TDCC, subject to customary post-closing adjustments, and recognized a pretax gain on the sale of $86 million, included in "Sundry income (expense) - net" in the consolidated statements of income. See Note 19 for more information on the cash management process. The Corporation evaluated the divestiture of the rail infrastructure operations and assets and determined it did not represent a strategic shift that had a major effect on the Corporation’s operations and financial results and did not qualify as an individually significant component of the Corporation. As a result, the divestiture is not reported as discontinued operations. Divestiture of Marine and Terminal Operations and Assets On September 14, 2020, TDCC entered into a definitive agreement to sell certain U.S. Gulf Coast marine and terminal operations and assets, including certain operations and assets located at UCC's site in St. Charles, to an affiliate of Royal Vopak ("Vopak affiliate"), and the transaction closed December 1, 2020. As part of this transaction, UCC sold certain related operations and assets located at its St. Charles site, including existing agreements to provide marine and terminal services to unrelated third parties, with a net book value of $41 million to the Vopak affiliate. UCC retained ownership of the site and the underlying real property where the divested operations are located. UCC and the Vopak affiliate entered into mutual long-term service agreements designed to ensure the continuation of marine and terminal services for UCC's existing St. Charles operations. The marine and terminal service agreements include fixed and variable fees that have initial terms of up to 25 years. Certain of these agreements contain leases, resulting in operating lease ROU assets and lease liabilities of $38 million. As part of the sale, UCC received proceeds of $226 million from TDCC, subject to customary post-closing adjustments, and recognized a pretax gain on the sale of $185 million, included in "Sundry income (expense) - net" in the consolidated statements of income. See Note 15 for additional information related to leases and Note 19 for additional information on the cash management process. The Corporation evaluated the divestiture of the marine and terminal operations and assets and determined it did not represent a strategic shift that had a major effect on the Corporation’s operations and financial results and did not qualify as an individually significant component of the Corporation. As a result, the divestiture is not reported as discontinued operations. Divestiture of Acetone Derivatives Assets On November 1, 2019, the Corporation completed the sale of its acetone derivatives product line to ALTIVIA Ketones & Additives, LLC for net proceeds of $17 million. The sale included acetone derivatives related inventory and production assets, as well as site infrastructure, land and utilities located in Institute, West Virginia. The sale also included railcars valued at $3 million, which were previously owned by TDCC and transferred to UCC in anticipation of the sale. The assets, with the exception of inventory and railcars, were written down to zero in the third quarter of 2019. In the fourth quarter of 2019, the Corporation recorded a $5 million pretax loss on the sale, included in "Sundry income (expense) - net" in the consolidated statements of income. The Corporation remains at the Institute, West Virginia, site as a tenant. See Notes 6 and 18 for additional information. The Corporation evaluated the divestiture of the acetone derivatives product line and determined it did not represent a strategic shift that had a major effect on the Corporation’s operations and financial results and did not qualify as an individually significant component of the Corporation. As a result, this divestiture was not reported as discontinued operations.

RESTRUCTURING AND ASSET RELATED

RESTRUCTURING AND ASSET RELATED CHARGES - NET	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Asset Related Charges - Net	RESTRUCTURING AND ASSET RELATED CHARGES - NET 2020 Restructuring Program On September 30, 2020, the Corporation's Board of Directors (the "Board") approved restructuring actions that were aligned to the structural cost improvement initiatives announced by Dow Inc. in response to the continued economic impact from the pandemic caused by coronavirus disease 2019 ("COVID-19"). The restructuring program is designed to reduce structural costs and enable the Corporation to further enhance competitiveness while the COVID-19 economic recovery gains traction. This program includes workforce cost reductions and actions to rationalize the Corporation's manufacturing assets. These actions are expected to be substantially complete by the end of 2021. As a result of these actions, in the third quarter of 2020, the Corporation recorded pretax restructuring charges of $13 million, consisting of severance and related benefit costs of $9 million and asset write-downs and write-offs of $4 million. The impact of these charges was included in "Restructuring and asset related charges - net" in the consolidated statements of income. At December 31, 2020, $8 million was included in "Accrued and other current liabilities" and $1 million was included in "Other noncurrent obligations" in the consolidated balance sheets. DowDuPont Cost Synergy Program In September and November 2017, the Corporation approved restructuring actions that were aligned with DowDuPont's synergy targets. In connection with this program, the Corporation recorded restructuring charges for severance and related benefit costs of $2 million in 2020, $4 million in 2019 and $3 million in 2018. These charges were shown as "Restructuring and asset related charges ‑ net” in the consolidated statements of income. The program was completed in 2020 with cumulative severance payments of $19 million. At December 31, 2019, severance of $16 million had been paid, leaving a liability of $1 million recorded in "Accrued and other current liabilities" in the consolidated balance sheets. The Corporation expects to incur additional costs in the future related to its restructuring activities. Future costs are expected to include demolition costs related to closed facilities and restructuring plan implementation costs; these costs will be recognized as incurred. The Corporation also expects to incur additional employee-related costs, including involuntary termination benefits, related to its other optimization activities. These costs cannot be reasonably estimated at this time. 2019 Asset Related Charges On August 13, 2019, the Corporation entered into a definitive agreement to sell its acetone derivatives product line to ALTIVIA Ketones & Additives, LLC. As a result of this planned transaction, the Corporation recognized a pretax impairment charge of $75 million in the third quarter of 2019. The impairment charge was included in "Restructuring and asset related charges - net" in the consolidated statements of income. See Notes 5 and 18 for additional information.

SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION	12 Months Ended
	Dec. 31, 2020
Supplementary Information [Abstract]
Supplementary Information	SUPPLEMENTARY INFORMATION Sundry Income (Expense) - Net In millions 2020 2019 2018 Gain on divestiture of marine and terminal operations and assets 1 $ 185 $ — $ — Gain on divestiture of rail infrastructure operations and assets 1 86 — — TDCC administrative and overhead fees 2 (31) (24) (30) Net commission expense - related company 2 (22) (23) (22) Non-operating pension and other postretirement benefit plan net costs 3 (20) (17) (1) Loss on early extinguishment of debt 4 (19) — — Net loss on divestiture of acetone derivatives assets 1 — (5) — Net loss on sales of property — (1) — Other - net (11) (12) (9) Total sundry income (expense) - net $ 168 $ (82) $ (62) 1. See Note 5 for additional information. 2. See Note 19 for additional information. 3. See Note 17 for additional information. 4. See Note 13 for additional information. Supplemental Cash Flow Information The following table shows cash paid for interest and income taxes for the years ended December 31, 2020, 2019 and 2018: Supplemental Cash Flow Information 2020 2019 2018 In millions Cash paid during year for: Interest $ 41 $ 37 $ 37 Income taxes $ 93 $ 136 $ 269

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Geographic Allocation of Income and Provision for Income Taxes In millions 2020 2019 2018 Income (loss) before income taxes Domestic $ 558 $ 696 $ 1,305 Foreign (1) (5) (3) Income before income taxes $ 557 $ 691 $ 1,302 Current tax expense Federal $ 82 $ 70 $ 166 State and local 2 4 6 Foreign — — 40 Total current tax expense $ 84 $ 74 $ 212 Deferred tax expense (benefit) Federal $ 42 $ (9) $ 27 State and local 4 (1) 8 Total deferred tax expense (benefit) $ 46 $ (10) $ 35 Provision for income taxes $ 130 $ 64 $ 247 Net income $ 427 $ 627 $ 1,055 Reconciliation to U.S. Statutory Rate 2020 2019 2018 Statutory U.S. federal income tax rate 21.0 % 21.0 % 21.0 % Unrecognized tax benefits (0.9) (1.0) (0.3) Federal tax accrual adjustments 3.0 1.7 (0.3) Restoration of tax basis — (12.2) — State and local tax impact 0.2 0.9 1.0 Other - net — (1.1) (2.4) Effective Tax Rate 1 23.3 % 9.3 % 19.0 % 1. The tax rate for 2020 was unfavorably impacted by an accrual to return adjustment. The tax rate for 2019 was favorably impacted by the restoration of tax basis in assets, driven by a court judgment that did not involve the Corporation. The tax rate for 2018 was favorably impacted by the Foreign Derived Intangible Income deduction and the Tax Cuts and Jobs Act of 2017. Deferred Tax Balances at Dec 31 2020 2019 In millions Assets Liabilities Assets Liabilities Property $ 22 $ 194 $ 14 $ 145 Tax loss and credit carryforwards 34 — 39 — Postretirement benefit obligations 318 — 275 — Other accruals and reserves 313 4 320 — Inventory 4 — 5 — Other - net 19 — 20 — Subtotal $ 710 $ 198 $ 673 $ 145 Valuation allowances 1 (18) — (21) — Total $ 692 $ 198 $ 652 $ 145 1. Primarily related to the realization of recorded tax benefits on state tax loss carryforwards from operations in the United States. Operating Loss and Tax Credit Carryforwards at Dec 31 2020 2019 In millions Assets Assets Operating loss carryforwards Expire within 5 years $ 21 $ 26 Expire after 5 years or indefinite expiration 7 7 Total operating loss carryforwards $ 28 $ 33 Tax credit carryforwards Expire after 5 years or indefinite expiration $ 6 $ 6 Total tax credit carryforwards $ 6 $ 6 Undistributed earnings of foreign subsidiaries and related companies that are deemed to be permanently invested amounted to $7 million at December 31, 2020 and $8 million at December 31, 2019. The unrecognized deferred tax liability on those earnings is not material. The following table provides a reconciliation of the Corporation's unrecognized tax benefits: Total Gross Unrecognized Tax Benefits In millions 2020 2019 2018 Total unrecognized tax benefits at Jan 1 $ 1 $ 1 $ 1 Total unrecognized tax benefits at Dec 31 $ 1 $ 1 $ 1 Total unrecognized tax benefits that, if recognized, would impact the effective tax rate $ 1 $ 1 $ 1 Total amount of interest and penalties (benefit) recognized in "Provision for income taxes" $ (5) $ (7) $ (5) In the first quarter of 2018, a settlement was reached for a tax matter regarding fees paid to the Corporation by a foreign nonconsolidated affiliate. As a result, the Corporation recorded an increase of $40 million to "Income taxes receivable" and "Income taxes payable" in the consolidated balance sheets. There was no impact to the consolidated statements of income. In the second quarter of 2018, a payment of $40 million was made for the settlement of the tax matter. The Corporation is included in TDCC's consolidated federal income tax group and DowDuPont's consolidated tax return through March 31, 2019. Current and deferred tax expenses are calculated for the Corporation as a stand-alone group and are allocated to the group from the consolidated totals, consistent with the TDCC-UCC Tax Sharing Agreement. The Corporation is currently under examination in a number of tax jurisdictions, including the U.S. federal and various state jurisdictions. It is reasonably possible that these examinations may be resolved in the next twelve months. The impact on the Corporation’s results of operations is not expected to be material. Tax years that remain subject to examination for the Corporation's major tax jurisdictions are shown below: Tax Years Subject to Examination by Major Tax Jurisdiction at Dec 31, 2020 Earliest Open Year Jurisdiction United States: Federal income tax 2004 State and local income tax 2004 Inherent uncertainties exist in estimates of tax contingencies due to changes in tax law, both legislated and concluded through the various jurisdictions' tax court systems. It is the opinion of the Corporation's management that the possibility is remote that costs in excess of those accrued will have a material impact on the Corporation's consolidated financial statements.

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	INVENTORIES The following table provides a breakdown of inventories: Inventories at Dec 31 In millions 2020 2019 Finished goods $ 157 $ 162 Work in process 23 31 Raw materials 38 47 Supplies 98 92 Total $ 316 $ 332 Adjustment of inventories to the LIFO basis (93) (85) Total inventories $ 223 $ 247 Inventories valued on the LIFO basis, principally U.S. chemicals and plastics product inventories, represented 50 percent of the total inventories at December 31, 2020 and 59 percent of the total inventories at December 31, 2019. A reduction of certain inventories resulted in the liquidation of certain LIFO inventory layers, which decreased pretax income $2 million in 2020 ($14 million in 2019) and had an immaterial impact on pretax income in 2018.

PROPERTY

PROPERTY	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property	PROPERTY The following table provides a breakdown of property: Property at Dec 31 Estimated Useful Lives (Years) In millions 2020 2019 Land and land improvements 0-25 $ 186 $ 258 Buildings 5-50 421 408 Machinery and equipment 3-20 5,974 6,097 Other property 3-30 372 357 Construction in progress — 136 127 Total property $ 7,089 $ 7,247 The following table provides information regarding depreciation expense and capitalized interest: In millions 2020 2019 2018 Depreciation expense $ 181 $ 175 $ 179 Capitalized interest $ 6 $ 8 $ 7

INVESTMENTS IN RELATED COMPANIE

INVESTMENTS IN RELATED COMPANIES	12 Months Ended
	Dec. 31, 2020
Investments in Related Companies [Abstract]
Investments in Related Companies	INVESTMENTS IN RELATED COMPANIES The Corporation's ownership interests in related companies at December 31, 2020 and 2019 were as follows: Investments in Related Companies at Dec 31 Ownership Interest Investment Balance In millions 2020 2019 2020 2019 Dow International Holdings Company 5 % 5 % $ 232 $ 232 Dow Quimica Mexicana S.A. de C.V. 15 % 15 % 5 5 Other — % — % — 1 Total investments in related companies $ 237 $ 238

INTANGIBLE ASSETS

INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2020
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible Assets	INTANGIBLE ASSETS The following table provides information regarding the Corporation's intangible assets: Intangible Assets at Dec 31 2020 2019 In millions Gross Carrying Amount Accum Amort Net Gross Carrying Amount Accum Amort Net Intangible assets with finite lives: Developed technology $ 33 $ (33) $ — $ 33 $ (33) $ — Software 80 (64) 16 79 (57) 22 Total intangible assets $ 113 $ (97) $ 16 $ 112 $ (90) $ 22 The following table provides information regarding amortization expense: Amortization Expense In millions 2020 2019 2018 Software, included in "Cost of sales" $ 8 $ 7 $ 6 Total estimated amortization expense for the next five fiscal years, including amounts expected to be capitalized, is as follows: Estimated Amortization Expense for Next Five Years In millions 2021 $ 6 2022 $ 5 2023 $ 2 2024 $ 1 2025 $ —

NOTES PAYABLE AND LONG-TERM DEB

NOTES PAYABLE AND LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Notes Payable and Long-term Debt	NOTES PAYABLE AND LONG-TERM DEBT Notes Payable at Dec 31 In millions 2020 2019 Notes payable to banks and other lenders $ — $ 6 Notes payable to related companies 33 32 Total notes payable $ 33 $ 38 Year-end average interest rates 1.25 % 1.88 % Long-Term Debt at Dec 31 2020 Average Rate 2020 2019 Average Rate 2019 In millions Promissory notes and debentures: Debentures due 2023 7.875 % $ 129 7.875 % $ 175 Debentures due 2025 6.79 % 12 6.79 % 12 Debentures due 2025 7.50 % 113 7.50 % 150 Debentures due 2096 7.75 % 135 7.75 % 135 Finance lease obligations 1 7 6 Unamortized debt discount and issuance costs (3) (4) Long-term debt due within one year (2) (1) Total long-term debt $ 391 $ 473 1. See Note 15 for additional information. Maturities of Long-Term Debt for Next Five Years at Dec 31, 2020 In millions 2021 $ 2 2022 $ 2 2023 $ 131 2024 $ 1 2025 $ 125 2020 Activity In September 2020, TDCC concluded a cash tender offer that included $83 million aggregate principal amount of certain notes issued by the Corporation. As a result of the tender offer, the Corporation retired $46 million of 7.875 percent notes due 2023 and $37 million of 7.50 percent notes due 2025 and recognized a $19 million loss on the early extinguishment of debt, included in "Sundry income (expense) - net" in the consolidated statements of income. Letters of Credit The Corporation utilizes letters of credit to support commitments made in the ordinary course of business. While the terms and amounts of letters of credit change, UCC generally has approximately $5 million of outstanding letters of credit at any given time.

COMMITMENTS AND CONTINGENT LIAB

COMMITMENTS AND CONTINGENT LIABILITIES	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	COMMITMENTS AND CONTINGENT LIABILITIES Environmental Matters Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated, based on current law and existing technologies. At December 31, 2020, the Corporation had accrued obligations of $133 million for probable environmental remediation and restoration costs, including $18 million for the remediation of Superfund sites. These obligations were included in "Accrued and other current liabilities" and "Other noncurrent obligations" in the consolidated balance sheets. This is management's best estimate of the costs for remediation and restoration with respect to environmental matters for which the Corporation has accrued liabilities, although it is reasonably possible that the ultimate cost with respect to these particular matters could range up to approximately two and a half times that amount. Consequently, it is reasonably possible that environmental remediation and restoration costs in excess of amounts accrued could have a material impact on the Corporation's results of operations, financial condition and cash flows. It is the opinion of the Corporation's management that the possibility is remote that costs in excess of the range disclosed will have a material impact on the Corporation's results of operations, financial condition and cash flows. Inherent uncertainties exist in these estimates primarily due to unknown environmental conditions, changing governmental regulations and legal standards regarding liability, and emerging remediation technologies for handling site remediation and restoration. As new or additional information becomes available and/or certain spending trends become known, management will evaluate such information in determination of the current estimate of the environmental liability. At December 31, 2019, the Corporation had accrued obligations of $132 million for probable environmental remediation and restoration costs, including $20 million for the remediation of Superfund sites. In the third quarter of 2019, the Corporation recorded a pretax charge of $55 million, included in "Cost of sales" in the consolidated statements of income, related to environmental remediation matters at a number of current and historical locations. The charge primarily resulted from the culmination of long-standing negotiations and discussions with regulators and agencies, including technical studies supporting higher cost estimates for final or staged remediation plans, and the Corporation’s review of its closure strategies and obligations to monitor ongoing operations and maintenance activities. The following table summarizes the activity in the Corporation's accrued obligations for environmental matters for the years ended December 31, 2020 and 2019: Accrued Liability for Environmental Matters In millions 2020 2019 Balance at Jan 1 $ 132 $ 94 Accrual adjustment 49 93 Payments against reserve (47) (55) Foreign currency impact (1) — Balance at Dec 31 $ 133 $ 132 The amounts charged to income on a pretax basis related to environmental remediation totaled $49 million in 2020, $93 million in 2019 and $38 million in 2018. Capital expenditures for environmental protection were $5 million in 2020, $11 million in 2019 and $9 million in 2018. Litigation Asbestos-Related Matters Introduction The Corporation is and has been involved in a large number of asbestos-related suits filed primarily in state courts during the past four decades. These suits principally allege personal injury resulting from exposure to asbestos-containing products and frequently seek both actual and punitive damages. The alleged claims primarily relate to products that UCC sold in the past, alleged exposure to asbestos-containing products located on UCC’s premises and UCC’s responsibility for asbestos suits filed against a former UCC subsidiary, Amchem Products, Inc. ("Amchem"). In many cases, plaintiffs are unable to demonstrate that they have suffered any compensable loss as a result of such exposure, or that injuries incurred in fact resulted from exposure to the Corporation’s products. The Corporation expects more asbestos-related suits to be filed against UCC and Amchem in the future, and will aggressively defend or reasonably resolve, as appropriate, both pending and future claims. Estimating the Asbestos-Related Liability Based on a study completed by Ankura Consulting Group, LLC ("Ankura") in January 2003, the Corporation increased its December 31, 2002, asbestos-related liability for pending and future claims for a 15-year period ending in 2017 to $2.2 billion, excluding future defense and processing costs. In subsequent years, the Corporation compared current asbestos claim and resolution activity to the results of the most recent Ankura study at each balance sheet date to determine whether the accrual continued to be appropriate. In 2016, Ankura completed a study to provide estimates for the undiscounted cost of disposing of pending and future claims against UCC and Amchem through the terminal year of 2049, including a reasonable forecast of future defense and processing costs. Based on the study and the Corporation’s internal review of asbestos claim and resolution activity, the Corporation determined estimating the liability through the terminal year of 2049 was more appropriate due to increased knowledge and data about the costs to resolve claims and diminished volatility in filing rates. The Corporation also determined that estimating and accruing a liability for future asbestos-related defense and processing costs was more appropriate as such costs represent expenditures related to legacy activities that do not contribute to current or future revenue generating activities of the Corporation and is also reflective of the manner in which the Corporation manages its asbestos-related exposure, including careful monitoring of the correlation between defense spending and resolution costs. As a result, in the fourth quarter of 2016, the Corporation recorded a $1,113 million increase in its asbestos-related liability for pending and future claims, including future defense and processing costs. Each October, the Corporation requests Ankura to review its historical asbestos claim and resolution activity through the third quarter of the current year, including asbestos-related defense and processing costs, to determine the appropriateness of updating the most recent study. In December 2018, Ankura completed a study of the Corporation's historical asbestos claim and resolution activity through September 30, 2018, including asbestos-related defense and processing costs, and provided estimates for the undiscounted cost of disposing of pending and future claims against UCC and Amchem through the terminal year of 2049. Based on the study and the Corporation's internal review process, it was determined that no adjustment to the accrual was required. In December 2019, Ankura stated that an update of its December 2018 study would not provide a more likely estimate of future events than the estimate reflected in the study and, therefore, the estimate in the study remained applicable. Based on the Corporation's internal review process and Ankura's response, the Corporation determined that no change to the accrual was required. At December 31, 2019, the asbestos-related liability for pending and future claims against UCC and Amchem, including future asbestos-related defense and processing costs, was $1,165 million, and approximately 18 percent of the recorded liability related to pending claims and approximately 82 percent related to future claims. In December 2020, Ankura completed a study of the Corporation's historical asbestos claim and resolution activity through September 30, 2020, including asbestos-related defense and processing costs, and provided estimates for the undiscounted cost of disposing of pending and future claims against UCC and Amchem through the terminal year of 2049. Based on the study and the Corporation's internal review process, it was determined that no adjustment to the accrual was required. At December 31, 2020, the asbestos-related liability for pending and future claims against UCC and Amchem, including future asbestos-related defense and processing costs, was $1,098 million, and approximately 22 percent of the recorded liability related to pending claims and approximately 78 percent related to future claims. Summary The Corporation's management believes the amounts recorded for the asbestos-related liability, including defense and processing costs, reflect reasonable and probable estimates of the liability based on current, known facts. However, future events, such as the number of new claims to be filed and/or received each year and the average cost of defending and disposing of each such claim, as well as the numerous uncertainties surrounding asbestos litigation in the United States over a significant period of time, could cause the actual costs for the Corporation to be higher or lower than those projected or those recorded. Any such event could result in an increase or decrease in the recorded liability. Because of the uncertainties described above, the Corporation cannot estimate the full range of the cost of resolving pending and future asbestos-related claims facing UCC and Amchem. As a result, it is reasonably possible that an additional cost of disposing of asbestos-related claims, including future defense and processing costs, could have a material impact on the Corporation's results of operations and cash flows for a particular period and on the consolidated financial position. Other Litigation The Corporation is also involved in a number of legal proceedings and claims with both private and governmental parties. These cover a wide range of matters, including, but not limited to: product liability; trade regulation; governmental tax and regulatory disputes; health, safety and environmental matters; employment matters; patent infringement; contracts; and commercial litigation. While it is not possible at this time to determine with certainty the ultimate outcome of any of the legal proceedings and claims referred to in this filing, management believes that the possibility is remote that the aggregate of all such other claims and lawsuits will have a material adverse impact on the results of operations, cash flows and financial position of the Corporation. Purchase Commitments The Corporation has outstanding purchase commitments and various commitments for take-or-pay or throughput agreements. The Corporation was not aware of any purchase commitments that were negotiated as part of a financing arrangement for the facilities that will provide the contracted goods or services or for the costs related to those goods or services at December 31, 2020 and 2019. Asset Retirement Obligations The Corporation has recognized asset retirement obligations related to capping activities at landfill sites in the United States and for demolition and remediation activities at manufacturing sites in the United States and United Arab Emirates. The aggregate carrying amount of these asset retirement obligations was $17 million at December 31, 2020 ($14 million at December 31, 2019). The Corporation has also recognized conditional asset retirement obligations related to asbestos encapsulation as a result of planned demolition and remediation activities at manufacturing sites in the United States. The aggregate carrying amount of conditional asset retirement obligations was $2 million at December 31, 2020 ($2 million at December 31, 2019). The discount rate used to calculate the Corporation's asset retirement obligations and conditional asset retirement obligations was 0.42 percent at December 31, 2020 (2.12 percent at December 31, 2019). These obligations are included in the consolidated balance sheets as “Accrued and other current liabilities” and "Other noncurrent obligations." The Corporation has not recognized conditional asset retirement obligations for which a fair value cannot be reasonably estimated in its consolidated financial statements. It is the opinion of management that the possibility is remote that such conditional asset retirement obligations, when estimable, will have a material impact on the Corporation's consolidated financial statements based on current costs.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	ACCUMULATED OTHER COMPREHENSIVE LOSS The changes in each component of AOCL for the years ended December 31, 2020, 2019 and 2018 were as follows: Accumulated Other Comprehensive Loss 2020 2019 2018 In millions Cumulative Translation Adjustment Beginning balance $ (56) $ (57) $ (59) Unrealized gains (losses) on foreign currency translation — 1 2 (Gains) losses reclassified from AOCL to net income 1 1 — — Other comprehensive income (loss), net of tax 1 1 2 Ending balance $ (55) $ (56) $ (57) Pension and Other Postretirement Benefits Beginning balance $ (1,609) $ (1,504) $ (1,293) Gains (losses) arising during the period (242) (213) (29) Less: Tax (expense) benefit 57 51 7 Net gains (losses) arising during the period (185) (162) (22) Amortization and recognition of net loss 2 103 75 85 Less: Tax expense (benefit) 3 (24) (18) (20) Net loss reclassified from AOCL to net income 79 57 65 Other comprehensive income (loss), net of tax (106) (105) 43 Reclassification of stranded tax effects 4 — — (254) Ending balance $ (1,715) $ (1,609) $ (1,504) Total AOCL ending balance $ (1,770) $ (1,665) $ (1,561) 1. Reclassified to "Sundry income (expense) - net." 2. These AOCL components are included in the computation of net periodic benefit cost of the Corporation's defined benefit pension and other postretirement benefit plans. See Note 17 for additional information. 3. Reclassified to "Provision for income taxes."

PENSION PLANS AND OTHER POSTRET

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS Pension Plans The Corporation has a defined benefit pension plan that covers substantially all employees in the United States. Benefits are based on length of service and the employee's three highest consecutive years of compensation. Employees hired on or after January 1, 2008, earn benefits that are based on a set percentage of annual pay, plus interest. The Corporation also has a non-qualified supplemental pension plan. The Corporation's funding policy is to contribute to the plan when pension laws or economics either require or encourage funding. In 2020, UCC contributed $2 million to its pension plans, including contributions to fund benefit payments for its non-qualified supplemental plan. UCC expects to contribute approximately $85 million to its pension plans in 2021. The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs are provided below: Pension Plan Assumptions Benefit Obligations Net Periodic Costs 2020 2019 2020 2019 2018 Discount rate 2.53 % 3.29 % 3.29 % 4.32 % 3.59 % Interest crediting rate for applicable benefits 4.50 % 4.50 % 4.50 % 4.50 % 4.50 % Rate of compensation increase 4.25 % 4.25 % 4.25 % 4.25 % 4.25 % Expected return on plan assets 6.80 % 6.80 % 6.80 % Other Postretirement Benefit Plans The Corporation provides certain health care and life insurance benefits to retired U.S. employees and survivors. The plan provides health care benefits, including hospital, physicians' services, drug and major medical expense coverage and life insurance benefits. The Corporation and the retiree share the cost of these benefits, with the Corporation portion increasing as the retiree has increased years of credited service, although there is a cap on the Corporation portion. The Corporation has the ability to change these benefits at any time. Employees hired after January 1, 2008, are not covered under this plan. The Corporation funds most of the cost of these health care and life insurance benefits as incurred. In 2020, UCC did not make any contributions to its other postretirement benefit plan trust. Likewise, UCC does not expect to contribute assets to its other postretirement benefit plan trust in 2021. The weighted-average assumptions used to determine other postretirement benefit plan obligations and net periodic benefit costs for the plan are provided in the following table: Other Postretirement Benefit Plan Assumptions Benefit Obligations at Dec 31 Net Periodic Costs for the Year Ended 2020 2019 2020 2019 2018 Discount rate 2.34 % 3.17 % 3.17 % 4.23 % 3.51 % Health care cost trend rate assumed for next year 6.75 % 6.25 % 6.25 % 6.50 % 6.75 % Rate to which the cost trend rate is assumed to decline (the ultimate health care cost trend rate) 5.00 % 5.00 % 5.00 % 5.00 % 5.00 % Year that the rate reaches the ultimate health care cost trend rate 2028 2025 2025 2025 2025 Assumptions The Corporation determines the expected long-term rate of return on plan assets by performing a detailed analysis of key economic and market factors driving historical returns for each asset class and formulating a projected return based on factors in the current environment. Factors considered include, but are not limited to, inflation, real economic growth, interest rate yield, interest rate spreads, and other valuation measures and market metrics. The expected long-term rate of return for each asset class is then weighted based on the strategic asset allocation approved by the governing body for each plan. The Corporation's historical experience with the pension fund asset performance is also considered. The Corporation uses the spot rate approach to determine the discount rate utilized to measure the service cost and interest cost components of net periodic pension and other postretirement benefit costs. Under the spot rate approach, the Corporation calculates service cost and interest cost by applying individual spot rates from the Willis Towers Watson U.S. RATE:Link 60-90 corporate yield curve (based on 60th to 90th percentile high-quality corporate bond yields) to the separate expected cash flow components of service cost and interest cost. The discount rates utilized to measure the pension and other postretirement obligations of the plans were based on the yield on high-quality corporate fixed income investments at the measurement date. Future expected actuarially determined cash flows for the plans are individually discounted at the spot rates under the Willis Towers Watson U.S. RATE:Link 60-90 corporate yield curve (based on 60th to 90th percentile high-quality corporate bond yields) to arrive at the plan’s obligations as of the measurement date. The Corporation utilizes a modified version of the Society of Actuaries’ mortality tables released in 2014 and a modified version of the generational mortality improvement scale released in 2018 for purposes of measuring the U.S. pension and other postretirement obligations, based on an evaluation of the mortality experience of its pension plans. Summarized information on the Corporation's pension and other postretirement benefit plans is as follows: Change in Projected Benefit Obligations, Plan Assets and Funded Status for All Plans Defined Benefit Other Postretirement Benefit Plan In millions 2020 2019 2020 2019 Change in projected benefit obligations: Benefit obligations at beginning of year $ 4,097 $ 3,786 $ 220 $ 215 Service cost 35 34 1 1 Interest cost 112 145 5 7 Actuarial changes in assumptions and experience 393 453 2 12 Benefits paid (281) (280) (8) (15) Other 1 (127) (41) — — Benefit obligations at end of year $ 4,229 $ 4,097 $ 220 $ 220 Change in plan assets: Fair value of plan assets at beginning of year $ 3,148 $ 3,005 $ — $ — Actual return on plan assets 344 464 — — Employer contributions 2 2 — — Asset transfers (10) (43) — — Benefits paid (281) (280) — — Other 2 (108) — — — Fair value of plan assets at end of year $ 3,095 $ 3,148 $ — $ — Funded status at end of year $ (1,134) $ (949) $ (220) $ (220) Net amounts recognized in the consolidated balance sheets at Dec 31: Accrued and other current liabilities $ (2) $ (2) $ (15) $ (17) Pension and other postretirement benefits - noncurrent (1,132) (947) (205) (203) Net amount recognized $ (1,134) $ (949) $ (220) $ (220) Pretax amounts recognized in accumulated other comprehensive loss at Dec 31: Net loss (gain) $ 2,267 $ 2,137 $ (52) $ (60) Prior service credit (9) (10) — — Pretax balance in accumulated other comprehensive loss at end of year $ 2,258 $ 2,127 $ (52) $ (60) 1. The 2020 impact relates primarily to the transfer of benefit obligations through the purchase of annuity contracts from an insurance company. 2. The 2020 impact relates to the purchase of annuity contracts associated with the transfer of benefit obligations to an insurance company. A significant component of the overall increase in the Corporation's benefit obligation for the year ended December 31, 2020 was due to the change in weighted-average discount rates, which decreased from 3.29 percent at December 31, 2019 to 2.53 percent at December 31, 2020. A significant component of the overall increase in the Corporation's benefit obligation for the year ended December 31, 2019 was due to the change in weighted-average discount rates, which decreased from 4.32 percent at December 31, 2018 to 3.29 percent at December 31, 2019. The accumulated benefit obligation for all defined benefit pension plans was $4.2 billion at December 31, 2020 and $4.1 billion at December 31, 2019. Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets at Dec 31 In millions 2020 2019 Accumulated benefit obligations $ 4,200 $ 4,071 Fair value of plan assets $ 3,095 $ 3,148 Pension Plans with Projected Benefit Obligations in Excess of Plan Assets at Dec 31 2020 2019 In millions Projected benefit obligations $ 4,229 $ 4,097 Fair value of plan assets $ 3,095 $ 3,148 Net Periodic Benefit Cost for All Plans for the Year Ended Dec 31 Defined Benefit Pension Plans Other Postretirement Benefit Plan In millions 2020 2019 2018 2020 2019 2018 Net Periodic Benefit Cost: Service cost $ 35 $ 34 $ 39 $ 1 $ 1 $ 1 Interest cost 112 145 128 5 7 6 Expected return on plan assets (200) (210) (218) — — — Amortization of prior service credit (1) (1) (1) — — — Amortization of net (gain) loss 110 84 95 (6) (8) (9) Net periodic benefit cost $ 56 $ 52 $ 43 $ — $ — $ (2) Changes in plan assets and benefit obligations recognized in other comprehensive (income) loss: Net (gain) loss $ 240 $ 202 $ 31 $ 2 $ 11 $ (2) Amortization of prior service credit 1 1 1 — — — Amortization of net gain (loss) (110) (84) (95) 6 8 9 Total recognized in other comprehensive (income) loss $ 131 $ 119 $ (63) $ 8 $ 19 $ 7 Total recognized in net periodic benefit cost and other comprehensive (income) loss $ 187 $ 171 $ (20) $ 8 $ 19 $ 5 Net periodic benefit cost, other than the service cost component, is included in "Sundry income (expense) - net" in the consolidated statements of income. See Note 7 for additional information. Estimated Future Benefit Payments The estimated future benefit payments, reflecting expected future service, as appropriate, are presented in the following table: Estimated Future Benefit Payments at Dec 31, 2020 Defined Benefit Pension Plans Other Postretirement Benefit Plan In millions 2021 $ 287 $ 15 2022 263 15 2023 260 15 2024 257 16 2025 254 16 2026 through 2030 1,190 73 Total $ 2,511 $ 150 Plan Assets Plan assets consist primarily of equity and fixed income securities of U.S. and foreign issuers, and include alternative investments such as real estate, private equity and other absolute return strategies. Plan assets totaled $3.1 billion at December 31, 2020 and $3.1 billion at December 31, 2019 and included no directly held common stock of Dow Inc. The Corporation's investment strategy for the plan assets is to manage the assets in relation to the liability in order to pay retirement benefits to plan participants over the life of the plans. This is accomplished by identifying and managing the exposure to various market risks, diversifying investments across various asset classes and earning an acceptable long-term rate of return consistent with an acceptable amount of risk, while considering the liquidity needs of the plan. The plan is permitted to use derivative instruments for investment purposes, as well as for hedging the underlying asset and liability exposures and rebalancing the asset allocation. The plan uses value-at-risk, stress testing, scenario analysis and Monte Carlo simulation to monitor and manage both the risk within the portfolios and the surplus risk of the plan. Equity securities primarily include investments in large- and small-cap companies located in both developed and emerging markets around the world. Fixed income securities are primarily U.S. dollar based and include U.S. treasuries and investment grade corporate bonds of companies diversified across industries. Alternative investments primarily include investments in real estate, private equity and absolute return strategies. Other significant investment types include various insurance contracts, and interest rate, equity and foreign exchange derivative investments and hedges. The Corporation mitigates the credit risk of investments by establishing guidelines with the investment managers that limit investment in any single issue or issuer to an amount that is not material to the portfolio being managed. These guidelines are monitored for compliance both by the Corporation and the external managers. Credit risk for hedging activity is mitigated by utilizing multiple counterparties, collateral support agreements, and centralized clearing where appropriate. A short-term investment money market fund is utilized as the sweep vehicle for the pension plan, which from time to time can represent a significant investment. Approximately 31 percent of the liability of the pension plan is covered by a participating group annuity issued by Prudential Insurance Company. The weighted-average target allocation for plan assets of the Corporation's pension plans is summarized as follows: Target Allocation for Plan Assets at Dec 31, 2020 Target Allocation Asset Category Equity securities 23 % Fixed income securities 45 Alternative investments 27 Other 5 Total 100 % Fair value calculations may not be indicative of net realizable value or reflective of future fair values. Furthermore, although the Corporation believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. For assets classified as Level 1 measurements (measured using quoted prices in active markets), the total fair value is either the price of the most recent trade at the time of the market close or the official close price, as defined by the exchange on which the asset is most actively traded on the last trading day of the period, multiplied by the number of units held without consideration of transaction costs. For assets classified as Level 2 measurements, where the security is frequently traded in less active markets, fair value is based on the closing price at the end of the period; where the security is less frequently traded, fair value is based on the price a dealer would pay for the security or similar securities, adjusted for any terms specific to that asset or liability. Market inputs are obtained from well-established and recognized vendors of market data and subjected to tolerance and quality checks. For derivative assets and liabilities, standard industry models are used to calculate the fair value of the various financial instruments based on significant observable market inputs such as foreign exchange rates, commodity prices, swap rates, interest rates, and implied volatilities obtained from various market sources. For other assets for which observable inputs are used, fair value is derived through the use of fair value models, such as a discounted cash flow model or other standard pricing models. For pension plan assets classified as Level 3 measurements, total fair value is based on significant unobservable inputs including assumptions where there is little, if any, market activity for the investment. Certain pension plan assets are held in funds where fair value is based on an estimated net asset value per share (or its equivalent) as of the most recently available fund financial statements which are received on a monthly or quarterly basis. These valuations are reviewed for reasonableness based on applicable sector, benchmark and company performance. Adjustments to valuations are made where appropriate to arrive at an estimated net asset value per share at the measurement date. These funds are not classified within the fair value hierarchy. The following table summarizes the bases used to measure the Corporation’s pension plan assets at fair value for the years ended December 31, 2020 and 2019: Basis of Fair Value Measurements Dec 31, 2020 Dec 31, 2019 In millions Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 210 $ 158 $ 52 $ — $ 160 $ 148 $ 12 $ — Equity securities: U.S. equity securities $ 313 $ 313 $ — $ — $ 346 $ 344 $ 2 $ — Non - U.S. equity securities 343 305 37 1 369 325 40 4 Total equity securities $ 656 $ 618 $ 37 $ 1 $ 715 $ 669 $ 42 $ 4 Fixed income securities: Debt - government-issued $ 820 $ 10 $ 810 $ — $ 812 $ 7 $ 805 $ — Debt - corporate-issued 494 15 479 — 455 9 446 — Debt - asset-backed 25 — 25 — 13 — 13 — Total fixed income securities $ 1,339 $ 25 $ 1,314 $ — $ 1,280 $ 16 $ 1,264 $ — Alternative investments: Private markets $ 6 $ — $ — $ 6 $ 5 $ — $ — $ 5 Derivatives - asset position 76 — 76 — — — — — Derivatives - liability position (38) — (38) — (3) — (3) — Total alternative investments $ 44 $ — $ 38 $ 6 $ 2 $ — $ (3) $ 5 Other investments $ (5) $ 4 $ (9) $ — $ 2 $ 5 $ (3) $ — Subtotal $ 2,244 $ 805 $ 1,432 $ 7 $ 2,159 $ 838 $ 1,312 $ 9 Investments measured at net asset value: Hedge funds $ 212 $ 266 Private markets 392 389 Real estate 257 341 Total investments measured at net asset value $ 861 $ 996 Items to reconcile to fair value of plan assets: Pension trust payables 1 (10) (7) Total $ 3,095 $ 3,148 1. Primarily payables for investment securities purchased. The following table summarizes the changes in fair value of Level 3 pension plan assets for the years ended December 31, 2020 and 2019: Fair Value Measurement of Level 3 Pension Plan Assets Equity Securities Alternative Investments Total In millions Balance at Jan 1, 2019 $ 6 $ — $ 6 Actual return on plan assets: Relating to assets held at Dec 31, 2019 — (5) (5) Purchases, sales and settlements (2) 10 8 Balance at Dec 31, 2019 $ 4 $ 5 $ 9 Actual return on plan assets: Relating to assets held at Dec 31, 2020 — 3 3 Relating to assets sold during 2020 — (4) (4) Purchases, sales and settlements (3) 2 (1) Balance at Dec 31, 2020 $ 1 $ 6 $ 7 Defined Contribution Plans In addition to the qualified defined benefit pension plan, U.S. employees may participate in defined contribution plans by contributing a portion of their compensation, which is partially matched by the Corporation. Expense recognized for all defined contribution plans was $7 million in 2020, $9 million in 2019 and $15 million in 2018.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	LEASESOperating lease ROU assets are included in "Operating lease right-of-use assets" and finance lease ROU assets are included in "Net property" in the consolidated balance sheets. With respect to lease liabilities, operating lease liabilities are included in "Operating lease liabilities - current" and "Operating lease liabilities - noncurrent," and finance lease liabilities are included in "Long-term debt due within one year" and "Long-Term Debt" in the consolidated balance sheets. The Corporation routinely leases product and utility production facilities, sales and administrative offices, warehouses and tanks for product storage, motor vehicles, railcars, computers, office machines and equipment. Some leases contain renewal provisions, purchase options and escalation clauses. The terms for these leased assets vary depending on the lease agreement. These leased assets have remaining lease terms of up to 20 years. The Corporation's lease agreements do not contain any material residual value guarantees or restrictive covenants. See Note 1 for additional information on leases. The components of lease cost for operating and finance leases for the years ended December 31, 2020 and 2019 were as follows: Lease Cost 2020 2019 In millions Operating lease cost $ 20 $ 21 Short-term lease cost 22 25 Variable lease cost 8 4 Amortization of right-of-use assets - finance 2 1 Total lease cost $ 52 $ 51 The following table provides supplemental cash flow information related to leases: Other Lease Information 2020 2019 In millions Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 19 $ 21 Financing cash flows for finance leases $ 2 $ 1 The following table summarizes the lease-related assets and liabilities recorded in the consolidated balance sheets at December 31, 2020 and 2019: Lease Position Balance Sheet Classification Dec 31, 2020 Dec 31, 2019 In millions Right-of-use assets obtained in exchange for lease obligations: Operating leases 1 $ 48 $ 105 Finance leases $ 3 $ — Assets Operating lease assets Operating lease right-of-use assets $ 123 $ 89 Finance lease assets Property 15 12 Finance lease amortization Accumulated depreciation (8) (6) Total lease assets $ 130 $ 95 Liabilities Current Operating Operating lease liabilities - current $ 19 $ 16 Finance Long-term debt due within one year 2 1 Noncurrent Operating Operating lease liabilities - noncurrent 105 74 Finance Long-Term Debt 5 5 Total lease liabilities $ 131 $ 96 1. Includes $99 million for the year ended December 31, 2019 related to the adoption of Topic 842. The weighted-average remaining lease term and discount rate for leases recorded in the consolidated balance sheets at December 31, 2020 and 2019 are provided below: Lease Term and Discount Rate Dec 31, 2020 Dec 31, 2019 Weighted-average remaining lease term Operating leases 7.5 years 6.3 years Finance leases 3.4 years 4.5 years Weighted-average discount rate Operating leases 3.28 % 4.13 % Finance leases 3.62 % 4.22 % The following table provides the maturities of lease liabilities at December 31, 2020: Maturities of Lease Liabilities Dec 31, 2020 In millions Operating Leases Finance Leases 2021 $ 23 $ 2 2022 22 2 2023 20 2 2024 19 1 2025 18 — 2026 and thereafter 38 — Total future undiscounted lease payments $ 140 $ 7 Less: Imputed interest 16 — Total present value of lease liabilities $ 124 $ 7 At December 31, 2020, the Corporation had additional leases of approximately $1 million for equipment which have not yet commenced. These leases are expected to commence in 2021 and 2022, with lease terms of 2 years.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Corporation's financial instruments are classified as Level 2 measurements. For assets and liabilities classified as Level 2 measurements, where the security is frequently traded in less active markets, fair value is based on the closing price at the end of the period; where the security is less frequently traded, fair value is based on the price a dealer would pay for the security or similar securities, adjusted for any terms specific to that asset or liability, or by using observable market data points of similar, more liquid securities to imply the price. Market inputs are obtained from well-established and recognized vendors of market data and subjected to tolerance and quality checks. Assets that are measured using significant other observable inputs are primarily valued by reference to quoted prices of similar assets in active markets, adjusted for any terms specific to that asset. For all other assets for which observable inputs are used, fair value is derived through the use of fair value models, such as a discounted cash flow model or other standard pricing models. There were no transfers between Levels 1 and 2 in the years ended December 31, 2020 and 2019. The following table summarizes the fair value of the Corporation's financial instruments at December 31, 2020 and 2019: Fair Value of Financial Instruments 2020 2019 In millions Cost Gain Loss Fair Value Cost Gain Loss Fair Value Cash equivalents 1 $ 10 $ — $ — $ 10 $ 10 $ — $ — $ 10 Long-term debt including debt due within one year $ (393) $ — $ (120) $ (513) $ (474) $ — $ (115) $ (589) 1. Money market fund is included in "Cash and cash equivalents" in the consolidated balance sheets and held at amortized cost, which approximates fair value. Cost approximates fair value for all other financial instruments. Fair Value Measurements on a Nonrecurring Basis In 2019, the Corporation recognized an impairment charge of $75 million resulting from the planned divestiture of its acetone derivatives product line to ALTIVIA Ketones & Additives, LLC. The transaction included the Corporation's acetone derivatives related inventory and production assets located in Institute, West Virginia, in addition to the site infrastructure, land and utilities and certain railcars previously owned by TDCC. The assets, classified as Level 3 measurements and valued using unobservable inputs, were written down to zero in 2019, except for inventory and railcars. The impairment charge was included in "Restructuring and asset related charges - net" in the consolidated statements of income. See Note 6 for additional information.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	RELATED PARTY TRANSACTIONS Product and Services Agreements The Corporation sells its products to TDCC to simplify the customer interface process. Products are sold to and purchased from TDCC at prices determined in accordance with the terms of an agreement between UCC and TDCC. After each quarter, the Corporation and TDCC 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 TDCC subsidiary and pays a commission to that TDCC subsidiary based on the volume and type of commodities and raw materials purchased. The Corporation also has a master services agreement with TDCC, whereby TDCC 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 TDCC, general administrative and overhead type services that TDCC 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. The following table summarizes UCC’s transactions with TDCC and a TDCC subsidiary related to product and services agreements for the years ended December 31, 2020, 2019 and 2018: Product and Services Agreements Transactions 2020 2019 2018 Income Statement In millions Classification TDCC Subsidiary: Commodity and raw materials purchases 1 $ 1,021 $ 1,100 $ 1,600 Cost of sales Commission expense $ 22 $ 23 $ 22 Sundry income (expense) - net TDCC: General administrative and overhead type services and service fee $ 31 $ 24 $ 30 Sundry income (expense) - net Activity-based costs $ 87 $ 87 $ 85 Cost of sales 1. Period end balances on hand are included in inventory. Amounts reported for 2019 and 2018 are approximate, as reported in prior years. Management believes the method used for determining expenses charged by TDCC is reasonable. TDCC 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 TDCC’s risk management philosophy, are provided as a service to UCC. Tax Sharing Agreement In accordance with the Tax Sharing Agreement between the Corporation and TDCC, the Corporation makes payments to TDCC to cover the Corporation's estimated federal tax liability; payments were $100 million in 2020, $184 million in 2019 and $220 million in 2018. Cash Management As part of TDCC’s cash management process, UCC is a party to revolving loans with TDCC that have interest rates based on LIBOR (London Interbank Offered Rate) with varying maturities. At December 31, 2020, the Corporation had a note receivable of $1.7 billion ($1.5 billion at December 31, 2019) from TDCC 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 TDCC that allows the Corporation to borrow or obtain credit enhancements up to an aggregate of $1 billion that matures on December 30, 2021. TDCC 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, 2020, $937 million was available under the revolving credit agreement ($937 million at December 31, 2019). The cash collateral was reported as "Noncurrent receivables from related companies" in the consolidated balance sheets. Dividends and Other Equity Transactions On a quarterly basis, the Corporation's Board reviews and determines if there will be a dividend distribution to its parent company and sole shareholder, TDCC. The Board takes into consideration the level of earnings and cash flows, among other factors, in determining the amount of the dividend distribution. The Corporation declared and paid cash dividends to TDCC totaling $362 million in 2020, $570 million in 2019, and $553 million in 2018. In the first quarter of 2019, in anticipation of the business separation activities to align TDCC's specialty products business with DowDuPont, UCC issued a stock dividend to TDCC for 63.4 percent of its ownership in DIHC, a cost method investment, which totaled $401 million. UCC also distributed assets and liabilities aligned with TDCC's specialty products business for an additional dividend to TDCC of $71 million. See Note 3 for additional information. In the fourth quarter of 2019, in anticipation of the Corporation's sale of its acetone derivatives product line to ALTIVIA Ketones & Additives, LLC, TDCC transferred railcars to UCC valued at $3 million as a capital contribution, which is included in "Additional paid in capital" in the consolidated balance sheets. See Notes 5, 6 and 18 for additional information.

BUSINESS AND GEOGRAPHIC AREAS

BUSINESS AND GEOGRAPHIC AREAS	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Business and Geographic Regions	BUSINESS AND GEOGRAPHIC REGIONS TDCC conducts its worldwide operations through principal product groups, and the Corporation's business activities comprise components of TDCC's principal product groups rather than stand-alone operations. The Corporation sells substantially all of its products to TDCC in order to simplify the customer interface process, at prices determined in accordance with the terms of an agreement between UCC and TDCC. Because there are no separate reportable business segments for the Corporation and no detailed business information is provided to a chief operating decision maker regarding the Corporation's stand-alone operations, the Corporation's results are reported as a single operating segment. Sales are attributed to geographic regions based on customer location; long-lived assets are attributed to geographic regions based on asset location. Sales to external customers and long-lived assets by geographic region were as follows: Geographic Region Information United States Asia Pacific Rest of World Total In millions 2020 Sales to external customers 1 $ 95 $ 23 $ 11 $ 129 Long-lived assets $ 1,226 $ 20 $ 19 $ 1,265 2019 Sales to external customers 1 $ 105 $ 24 $ 9 $ 138 Long-lived assets $ 1,329 $ 18 $ 22 $ 1,369 2018 Sales to external customers 1 $ 124 $ 2 $ 10 $ 136 Long-lived assets $ 1,413 $ 10 $ 25 $ 1,448 1. Of total sales to external customers, sales in Malaysia were approximately 18 percent in 2020, 17 percent in 2019 and 1 percent in 2018, and are included in Asia Pacific.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation Except as otherwise indicated by the context, the terms "Corporation" and "UCC" as used herein mean Union Carbide Corporation and its consolidated subsidiaries. The accompanying consolidated financial statements of the Corporation were prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and include the assets, liabilities, revenues and expenses of all majority-owned subsidiaries over which the Corporation exercises control and, when applicable, entities for which the Corporation has a controlling financial interest. Investments in nonconsolidated affiliates (20-50 percent owned companies, joint ventures and partnerships) are accounted for using the equity method. 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. The Corporation’s business activities comprise components of TDCC’s global businesses rather than stand-alone operations. Because there are no separate reportable business segments for UCC under the accounting guidance related to segment reporting and no detailed business information is provided to a chief operating decision maker regarding the Corporation’s stand-alone operations, the Corporation’s results are reported as a single operating segment. On April 1, 2019, DowDuPont Inc. (“DowDuPont” and effective June 3, 2019, n/k/a DuPont de Nemours, Inc.) completed the separation of its materials science business and Dow Inc. became the direct parent company of TDCC and its consolidated subsidiaries. The separation was contemplated by the merger of equals transaction effective August 31, 2017, under the Agreement and Plan of Merger, dated as of December 11, 2015, as amended on March 31, 2017. TDCC and E. I. du Pont de Nemours and Company and its consolidated subsidiaries ("Historical DuPont") each merged with subsidiaries of DowDuPont, and, as a result, TDCC and Historical DuPont became subsidiaries of DowDuPont (the “Merger”). Subsequent to the Merger, TDCC and Historical DuPont engaged in a series of internal reorganization and realignment steps to realign their businesses into three subgroups: agriculture, materials science and specialty products. Dow Inc. was formed as a wholly owned subsidiary of DowDuPont to serve as the holding company for the materials science business. UCC remains a wholly owned subsidiary of TDCC. See Note 3 for additional information. 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 19 for additional information.
Use of Estimates in Financial Statement Preparation	Use of Estimates in Financial Statement Preparation The preparation of financial statements in accordance with U.S. GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. The Corporation's consolidated financial statements include amounts that are based on management's best estimates and judgments. Actual results could differ from those estimates.
Asbestos-Related Matters	Asbestos-Related Matters Accruals for asbestos-related matters, including defense and processing costs, are recorded based on an analysis of claim and resolution activity, defense spending and pending and future claims. These accruals are assessed at each balance sheet date to determine if the asbestos-related liability remains appropriate. Accruals for asbestos-related matters are included in the consolidated balance sheets in "Asbestos-related liabilities - current" and "Asbestos-related liabilities - noncurrent." See Note 14 for additional information.
Legal Costs	Legal Costs The Corporation expenses legal costs as incurred, with the exception of defense and processing costs associated with asbestos-related matters.
Foreign Currency Translation	Foreign Currency Translation While the Corporation's consolidated subsidiaries are primarily based in the United States, the Corporation has small subsidiaries in Asia Pacific and the rest of the world. For those subsidiaries, the local currency has been primarily used as the functional currency. Translation gains and losses of those operations that use local currency as the functional currency are included in the consolidated balance sheets in "Accumulated other comprehensive loss" ("AOCL"). Where the U.S. dollar is used as the functional currency, foreign currency translation gains and losses are reflected in income.
Environmental Matters	Environmental Matters Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated based on current law and existing technologies. These accruals are adjusted periodically as assessment and remediation efforts progress or as additional technical or legal information becomes available. Accruals for environmental liabilities are included in the consolidated balance sheets in "Accrued and other current liabilities" and "Other noncurrent obligations" at undiscounted amounts. Accruals for related insurance or other third-party recoveries for environmental liabilities are recorded when it is probable that a recovery will be realized and are included in the consolidated balance sheets in "Accounts receivable - Other." Environmental costs are capitalized if the costs extend the life of the property, increase its capacity, and/or mitigate or prevent contamination from future operations. Environmental costs are also capitalized in recognition of legal asset retirement obligations resulting from the acquisition, construction and/or normal operation of a long-lived asset. Costs related to environmental contamination treatment and cleanup are charged to expense. Estimated future incremental operations, maintenance and management costs directly related to remediation are accrued when such costs are probable and reasonably estimable.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include time deposits and investments with maturities of three months or less at the time of purchase.
Financial Instruments	Financial Instruments The Corporation calculates the fair value of financial instruments using quoted market prices when available. When quoted market prices are not available for financial instruments, the Corporation uses standard pricing models with market-based inputs that take into account the present value of estimated future cash flows.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value. The method of determining cost for each subsidiary varies among last-in, first-out ("LIFO"); first-in, first-out ("FIFO"); and average cost, and is used consistently from year to year. The Corporation routinely exchanges and swaps raw materials and finished goods with other companies to reduce delivery time, freight and other transportation costs. These transactions are treated as non-monetary exchanges and are valued at cost.
Property	Property Land, buildings and equipment are carried at cost less accumulated depreciation. Property under finance lease agreements is carried at the present value of lease payments over the lease term less accumulated amortization. Depreciation is based on the estimated service lives of depreciable assets and is calculated using the straight-line method. Fully depreciated assets are retained in property and accumulated depreciation accounts until they are removed from service. In the case of disposals, assets and related accumulated depreciation are removed from the accounts, and the net amounts, less proceeds from disposal, are included in income.
Impairment and Disposal of Long-Lived Assets	Impairment and Disposal of Long-Lived Assets The Corporation evaluates long-lived assets and certain identifiable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. When undiscounted future cash flows are not expected to be sufficient to recover an asset's carrying amount, the asset is written down to its fair value based on bids received from third parties or a discounted cash flow analysis based on market participant assumptions. Long-lived assets to be disposed of by sale, if material, are classified as held for sale and reported at the lower of carrying amount or fair value less cost to sell, and depreciation is ceased. Long-lived assets to be disposed of other than by sale are classified as held and used until they are disposed of and reported at the lower of carrying amount or fair value, and depreciation is recognized over the remaining useful life of the assets.
Other Intangible Assets	Other Intangible Assets Finite-lived intangible assets, such as developed technology and software, are amortized over their estimated useful lives, generally on a straight-line basis for periods ranging primarily from three to twenty years. Asset Retirement Obligations The Corporation records asset retirement obligations as incurred and reasonably estimable, including obligations for which the timing and/or method of settlement are conditional on a future event that may or may not be within the control of the Corporation. The fair values of obligations are recorded as liabilities on a discounted basis and are accreted over time for the change in present value. Costs associated with the liabilities are capitalized and amortized over the estimated remaining useful life of the asset, generally for periods of 10 years or less.
Investments in Related Companies	Investments in Related Companies Investments in related companies consist of the Corporation's ownership interests in TDCC subsidiaries located in the United States and Latin America. The Corporation accounts for these investments using the cost method as it does not have significant influence over the operating and financial policies of these related companies.
Lessee, Leases [Policy Text Block]	Leases Effective January 1, 2019, UCC adopted Accounting Standards Update ("ASU") 2016-02, "Leases (Topic 842)," and the associated ASUs (collectively, "Topic 842"). The Corporation added the following significant accounting policy for leases as a result of the adoption of Topic 842: UCC determines whether a contract contains a lease at contract inception. A contract contains a lease if there is an identified asset and the Corporation has the right to control the asset. Operating lease right-of-use (“ROU”) assets represent UCC’s right to use an underlying asset for the lease term, and lease liabilities represent UCC’s obligation to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. UCC uses the incremental borrowing rate in determining the present value of lease payments, unless the implicit rate is readily determinable. If lease terms include options to extend or terminate the lease, the ROU asset and lease liability are measured based on the reasonably certain decision. Leases with a term of 12 months or less at the commencement date are not recognized on the balance sheet and are expensed as incurred. UCC has lease agreements with lease and non-lease components, which are accounted for as a single lease component for nearly all classes of leased assets for which UCC is the lessee. Additionally, for certain equipment leases, the portfolio approach is applied to account for the operating lease ROU assets and lease liabilities. In the consolidated statements of income, lease expense for operating lease payments is recognized on a straight-line basis over the lease term. For finance leases, interest expense is recognized on the lease liability and the ROU asset is amortized over the lease term. Some leasing arrangements require variable payments that are dependent upon usage or output, or may vary for other reasons, such as insurance or tax payments. Variable lease payments are recognized as incurred and are not presented as part of the ROU asset or lease liability. See Note 15 for additional information.
Revenue	Revenue Substantially all of the Corporation's revenues are generated by sales to TDCC. Revenue for product sales to related companies is recognized when the related company obtains control of the product, which occurs either at the time that production is complete or shipped free on board ("FOB") from UCC's manufacturing facility, in accordance with the sales agreement between the Corporation and TDCC. The Corporation recognizes revenue for product sales to trade customers when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Corporation expects to receive in exchange for those goods or services. To determine revenue recognition, the Corporation performs the following five steps: (1) identify the contract(s) with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) the entity satisfies a performance obligation. See Note 4 for additional information.
Severance Costs	Severance Costs Management routinely reviews its operations around the world in an effort to ensure competitiveness across its operations and geographic regions. When the reviews result in a workforce reduction related to the shutdown of facilities or other optimization activities, severance benefits are provided to employees primarily under ongoing benefit arrangements. These severance costs are accrued once management commits to a plan of termination and it becomes probable that employees will be entitled to benefits at amounts that can be reasonably estimated.
Integration and Separation Costs	Integration and Separation Costs The Corporation classifies expenses related to the Merger and separation as integration and separation costs. Merger and separation related costs include: post-Merger integration expenses and costs incurred for the separation of TDCC’s agriculture business, materials science business and specialty products business. Integration and separation costs primarily consist of financial advisor, information technology, legal, accounting, consulting and other professional advisory fees associated with preparation and execution of these activities. Integration and separation costs related to the Merger and separation were completed as of December 31, 2020.
Income Taxes	Income Taxes The Corporation accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities using enacted tax rates. The effect of a change in tax rates on deferred tax assets or liabilities is recognized in income in the period that includes the enactment date. The Corporation is included in the same consolidated federal income tax group and consolidated income tax return as TDCC. The Corporation accounts for its income taxes following the formula in the TDCC-UCC Tax Sharing Agreement used to compute the amount due to TDCC or UCC for UCC's share of taxable income and tax attributes on the consolidated income tax return. This method generally follows the separate return method. The amounts reported as income taxes payable or receivable represent the Corporation's payment obligation (or refundable amount) to TDCC based on a theoretical tax liability calculated on a separate return method. The Corporation recognizes the financial statement effects of an uncertain income tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. The Corporation accrues for non-income tax contingencies when it is probable that a liability to a taxing authority has been incurred and the amount of the contingency can be reasonably estimated. Provision is made for taxes on undistributed earnings of foreign subsidiaries and related companies to the extent that such earnings are not deemed to be permanently invested.

SUPPLEMENTARY INFORMATION_2

SUPPLEMENTARY INFORMATION	12 Months Ended
	Dec. 31, 2020
Supplementary Information [Abstract]
Sundry Income, Net	Sundry Income (Expense) - Net In millions 2020 2019 2018 Gain on divestiture of marine and terminal operations and assets 1 $ 185 $ — $ — Gain on divestiture of rail infrastructure operations and assets 1 86 — — TDCC administrative and overhead fees 2 (31) (24) (30) Net commission expense - related company 2 (22) (23) (22) Non-operating pension and other postretirement benefit plan net costs 3 (20) (17) (1) Loss on early extinguishment of debt 4 (19) — — Net loss on divestiture of acetone derivatives assets 1 — (5) — Net loss on sales of property — (1) — Other - net (11) (12) (9) Total sundry income (expense) - net $ 168 $ (82) $ (62) 1. See Note 5 for additional information. 2. See Note 19 for additional information. 3. See Note 17 for additional information. 4. See Note 13 for additional information.
Schedule of Cash Flow, Supplemental Disclosures	The following table shows cash paid for interest and income taxes for the years ended December 31, 2020, 2019 and 2018: Supplemental Cash Flow Information 2020 2019 2018 In millions Cash paid during year for: Interest $ 41 $ 37 $ 37 Income taxes $ 93 $ 136 $ 269

INCOME TAXES_2

INCOME TAXES	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of geographic allocation of income	Geographic Allocation of Income and Provision for Income Taxes In millions 2020 2019 2018 Income (loss) before income taxes Domestic $ 558 $ 696 $ 1,305 Foreign (1) (5) (3) Income before income taxes $ 557 $ 691 $ 1,302 Current tax expense Federal $ 82 $ 70 $ 166 State and local 2 4 6 Foreign — — 40 Total current tax expense $ 84 $ 74 $ 212 Deferred tax expense (benefit) Federal $ 42 $ (9) $ 27 State and local 4 (1) 8 Total deferred tax expense (benefit) $ 46 $ (10) $ 35 Provision for income taxes $ 130 $ 64 $ 247 Net income $ 427 $ 627 $ 1,055
Schedule of Effective Income Tax Rate Reconciliation	Reconciliation to U.S. Statutory Rate 2020 2019 2018 Statutory U.S. federal income tax rate 21.0 % 21.0 % 21.0 % Unrecognized tax benefits (0.9) (1.0) (0.3) Federal tax accrual adjustments 3.0 1.7 (0.3) Restoration of tax basis — (12.2) — State and local tax impact 0.2 0.9 1.0 Other - net — (1.1) (2.4) Effective Tax Rate 1 23.3 % 9.3 % 19.0 % 1. The tax rate for 2020 was unfavorably impacted by an accrual to return adjustment. The tax rate for 2019 was favorably impacted by the restoration of tax basis in assets, driven by a court judgment that did not involve the Corporation. The tax rate for 2018 was favorably impacted by the Foreign Derived Intangible Income deduction and the Tax Cuts and Jobs Act of 2017.
Schedule of Deferred Tax Assets and Liabilities	Deferred Tax Balances at Dec 31 2020 2019 In millions Assets Liabilities Assets Liabilities Property $ 22 $ 194 $ 14 $ 145 Tax loss and credit carryforwards 34 — 39 — Postretirement benefit obligations 318 — 275 — Other accruals and reserves 313 4 320 — Inventory 4 — 5 — Other - net 19 — 20 — Subtotal $ 710 $ 198 $ 673 $ 145 Valuation allowances 1 (18) — (21) — Total $ 692 $ 198 $ 652 $ 145 1. Primarily related to the realization of recorded tax benefits on state tax loss carryforwards from operations in the United States.
Summary of Operating Loss Carryforwards	Operating Loss and Tax Credit Carryforwards at Dec 31 2020 2019 In millions Assets Assets Operating loss carryforwards Expire within 5 years $ 21 $ 26 Expire after 5 years or indefinite expiration 7 7 Total operating loss carryforwards $ 28 $ 33 Tax credit carryforwards Expire after 5 years or indefinite expiration $ 6 $ 6 Total tax credit carryforwards $ 6 $ 6
Schedule of Total Gross Unrecognized Tax Benefits	The following table provides a reconciliation of the Corporation's unrecognized tax benefits: Total Gross Unrecognized Tax Benefits In millions 2020 2019 2018 Total unrecognized tax benefits at Jan 1 $ 1 $ 1 $ 1 Total unrecognized tax benefits at Dec 31 $ 1 $ 1 $ 1 Total unrecognized tax benefits that, if recognized, would impact the effective tax rate $ 1 $ 1 $ 1 Total amount of interest and penalties (benefit) recognized in "Provision for income taxes" $ (5) $ (7) $ (5)
Schedule of Tax Years Subject to Examination by Major Tax Jurisdiction	Tax years that remain subject to examination for the Corporation's major tax jurisdictions are shown below: Tax Years Subject to Examination by Major Tax Jurisdiction at Dec 31, 2020 Earliest Open Year Jurisdiction United States: Federal income tax 2004 State and local income tax 2004

INVENTORIES_2

INVENTORIES	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	The following table provides a breakdown of inventories: Inventories at Dec 31 In millions 2020 2019 Finished goods $ 157 $ 162 Work in process 23 31 Raw materials 38 47 Supplies 98 92 Total $ 316 $ 332 Adjustment of inventories to the LIFO basis (93) (85) Total inventories $ 223 $ 247

PROPERTY_2

PROPERTY	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of property	The following table provides a breakdown of property: Property at Dec 31 Estimated Useful Lives (Years) In millions 2020 2019 Land and land improvements 0-25 $ 186 $ 258 Buildings 5-50 421 408 Machinery and equipment 3-20 5,974 6,097 Other property 3-30 372 357 Construction in progress — 136 127 Total property $ 7,089 $ 7,247
Schedule of other items related to property	The following table provides information regarding depreciation expense and capitalized interest: In millions 2020 2019 2018 Depreciation expense $ 181 $ 175 $ 179 Capitalized interest $ 6 $ 8 $ 7

INVESTMENTS IN RELATED COMPAN_2

INVESTMENTS IN RELATED COMPANIES	12 Months Ended
	Dec. 31, 2020
Investments in Related Companies [Abstract]
Schedule of Cost Method Investments	The Corporation's ownership interests in related companies at December 31, 2020 and 2019 were as follows: Investments in Related Companies at Dec 31 Ownership Interest Investment Balance In millions 2020 2019 2020 2019 Dow International Holdings Company 5 % 5 % $ 232 $ 232 Dow Quimica Mexicana S.A. de C.V. 15 % 15 % 5 5 Other — % — % — 1 Total investments in related companies $ 237 $ 238

INTANGIBLE ASSETS_2

INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2020
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Schedule of Intangible Assets and Goodwill	The following table provides information regarding the Corporation's intangible assets: Intangible Assets at Dec 31 2020 2019 In millions Gross Carrying Amount Accum Amort Net Gross Carrying Amount Accum Amort Net Intangible assets with finite lives: Developed technology $ 33 $ (33) $ — $ 33 $ (33) $ — Software 80 (64) 16 79 (57) 22 Total intangible assets $ 113 $ (97) $ 16 $ 112 $ (90) $ 22
Schedule Of Finite Lived Intangible Assets Amortization Expense Table	The following table provides information regarding amortization expense: Amortization Expense In millions 2020 2019 2018 Software, included in "Cost of sales" $ 8 $ 7 $ 6
Schedule of Expected Amortization Expense	Total estimated amortization expense for the next five fiscal years, including amounts expected to be capitalized, is as follows: Estimated Amortization Expense for Next Five Years In millions 2021 $ 6 2022 $ 5 2023 $ 2 2024 $ 1 2025 $ —

NOTES PAYABLE AND LONG-TERM D_2

NOTES PAYABLE AND LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Short-term Debt	Notes Payable at Dec 31 In millions 2020 2019 Notes payable to banks and other lenders $ — $ 6 Notes payable to related companies 33 32 Total notes payable $ 33 $ 38 Year-end average interest rates 1.25 % 1.88 %
Schedule of Long-term Debt Instruments	Long-Term Debt at Dec 31 2020 Average Rate 2020 2019 Average Rate 2019 In millions Promissory notes and debentures: Debentures due 2023 7.875 % $ 129 7.875 % $ 175 Debentures due 2025 6.79 % 12 6.79 % 12 Debentures due 2025 7.50 % 113 7.50 % 150 Debentures due 2096 7.75 % 135 7.75 % 135 Finance lease obligations 1 7 6 Unamortized debt discount and issuance costs (3) (4) Long-term debt due within one year (2) (1) Total long-term debt $ 391 $ 473
Schedule of Maturities of Long-term Debt	Maturities of Long-Term Debt for Next Five Years at Dec 31, 2020 In millions 2021 $ 2 2022 $ 2 2023 $ 131 2024 $ 1 2025 $ 125

COMMITMENTS AND CONTINGENT LI_2

COMMITMENTS AND CONTINGENT LIABILITIES	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Environmental Loss Contingency Disclosure	The following table summarizes the activity in the Corporation's accrued obligations for environmental matters for the years ended December 31, 2020 and 2019: Accrued Liability for Environmental Matters In millions 2020 2019 Balance at Jan 1 $ 132 $ 94 Accrual adjustment 49 93 Payments against reserve (47) (55) Foreign currency impact (1) — Balance at Dec 31 $ 133 $ 132

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The changes in each component of AOCL for the years ended December 31, 2020, 2019 and 2018 were as follows: Accumulated Other Comprehensive Loss 2020 2019 2018 In millions Cumulative Translation Adjustment Beginning balance $ (56) $ (57) $ (59) Unrealized gains (losses) on foreign currency translation — 1 2 (Gains) losses reclassified from AOCL to net income 1 1 — — Other comprehensive income (loss), net of tax 1 1 2 Ending balance $ (55) $ (56) $ (57) Pension and Other Postretirement Benefits Beginning balance $ (1,609) $ (1,504) $ (1,293) Gains (losses) arising during the period (242) (213) (29) Less: Tax (expense) benefit 57 51 7 Net gains (losses) arising during the period (185) (162) (22) Amortization and recognition of net loss 2 103 75 85 Less: Tax expense (benefit) 3 (24) (18) (20) Net loss reclassified from AOCL to net income 79 57 65 Other comprehensive income (loss), net of tax (106) (105) 43 Reclassification of stranded tax effects 4 — — (254) Ending balance $ (1,715) $ (1,609) $ (1,504) Total AOCL ending balance $ (1,770) $ (1,665) $ (1,561) 1. Reclassified to "Sundry income (expense) - net." 2. These AOCL components are included in the computation of net periodic benefit cost of the Corporation's defined benefit pension and other postretirement benefit plans. See Note 17 for additional information. 3. Reclassified to "Provision for income taxes."

PENSION PLANS AND OTHER POSTR_2

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	Summarized information on the Corporation's pension and other postretirement benefit plans is as follows: Change in Projected Benefit Obligations, Plan Assets and Funded Status for All Plans Defined Benefit Other Postretirement Benefit Plan In millions 2020 2019 2020 2019 Change in projected benefit obligations: Benefit obligations at beginning of year $ 4,097 $ 3,786 $ 220 $ 215 Service cost 35 34 1 1 Interest cost 112 145 5 7 Actuarial changes in assumptions and experience 393 453 2 12 Benefits paid (281) (280) (8) (15) Other 1 (127) (41) — — Benefit obligations at end of year $ 4,229 $ 4,097 $ 220 $ 220 Change in plan assets: Fair value of plan assets at beginning of year $ 3,148 $ 3,005 $ — $ — Actual return on plan assets 344 464 — — Employer contributions 2 2 — — Asset transfers (10) (43) — — Benefits paid (281) (280) — — Other 2 (108) — — — Fair value of plan assets at end of year $ 3,095 $ 3,148 $ — $ — Funded status at end of year $ (1,134) $ (949) $ (220) $ (220) Net amounts recognized in the consolidated balance sheets at Dec 31: Accrued and other current liabilities $ (2) $ (2) $ (15) $ (17) Pension and other postretirement benefits - noncurrent (1,132) (947) (205) (203) Net amount recognized $ (1,134) $ (949) $ (220) $ (220) Pretax amounts recognized in accumulated other comprehensive loss at Dec 31: Net loss (gain) $ 2,267 $ 2,137 $ (52) $ (60) Prior service credit (9) (10) — — Pretax balance in accumulated other comprehensive loss at end of year $ 2,258 $ 2,127 $ (52) $ (60) 1. The 2020 impact relates primarily to the transfer of benefit obligations through the purchase of annuity contracts from an insurance company. 2. The 2020 impact relates to the purchase of annuity contracts associated with the transfer of benefit obligations to an insurance company.
Schedule of Projected Benefit Obligations in Excess of Fair Value of Plan Assets	Pension Plans with Projected Benefit Obligations in Excess of Plan Assets at Dec 31 2020 2019 In millions Projected benefit obligations $ 4,229 $ 4,097 Fair value of plan assets $ 3,095 $ 3,148
Schedule of Net Benefit Costs	Net Periodic Benefit Cost for All Plans for the Year Ended Dec 31 Defined Benefit Pension Plans Other Postretirement Benefit Plan In millions 2020 2019 2018 2020 2019 2018 Net Periodic Benefit Cost: Service cost $ 35 $ 34 $ 39 $ 1 $ 1 $ 1 Interest cost 112 145 128 5 7 6 Expected return on plan assets (200) (210) (218) — — — Amortization of prior service credit (1) (1) (1) — — — Amortization of net (gain) loss 110 84 95 (6) (8) (9) Net periodic benefit cost $ 56 $ 52 $ 43 $ — $ — $ (2) Changes in plan assets and benefit obligations recognized in other comprehensive (income) loss: Net (gain) loss $ 240 $ 202 $ 31 $ 2 $ 11 $ (2) Amortization of prior service credit 1 1 1 — — — Amortization of net gain (loss) (110) (84) (95) 6 8 9 Total recognized in other comprehensive (income) loss $ 131 $ 119 $ (63) $ 8 $ 19 $ 7 Total recognized in net periodic benefit cost and other comprehensive (income) loss $ 187 $ 171 $ (20) $ 8 $ 19 $ 5
Schedule of Expected Benefit Payments	The estimated future benefit payments, reflecting expected future service, as appropriate, are presented in the following table: Estimated Future Benefit Payments at Dec 31, 2020 Defined Benefit Pension Plans Other Postretirement Benefit Plan In millions 2021 $ 287 $ 15 2022 263 15 2023 260 15 2024 257 16 2025 254 16 2026 through 2030 1,190 73 Total $ 2,511 $ 150
Schedule of Allocation of Plan Assets	The weighted-average target allocation for plan assets of the Corporation's pension plans is summarized as follows: Target Allocation for Plan Assets at Dec 31, 2020 Target Allocation Asset Category Equity securities 23 % Fixed income securities 45 Alternative investments 27 Other 5 Total 100 %
Schedule of Defined Benefit Plans Disclosures	The following table summarizes the bases used to measure the Corporation’s pension plan assets at fair value for the years ended December 31, 2020 and 2019: Basis of Fair Value Measurements Dec 31, 2020 Dec 31, 2019 In millions Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 210 $ 158 $ 52 $ — $ 160 $ 148 $ 12 $ — Equity securities: U.S. equity securities $ 313 $ 313 $ — $ — $ 346 $ 344 $ 2 $ — Non - U.S. equity securities 343 305 37 1 369 325 40 4 Total equity securities $ 656 $ 618 $ 37 $ 1 $ 715 $ 669 $ 42 $ 4 Fixed income securities: Debt - government-issued $ 820 $ 10 $ 810 $ — $ 812 $ 7 $ 805 $ — Debt - corporate-issued 494 15 479 — 455 9 446 — Debt - asset-backed 25 — 25 — 13 — 13 — Total fixed income securities $ 1,339 $ 25 $ 1,314 $ — $ 1,280 $ 16 $ 1,264 $ — Alternative investments: Private markets $ 6 $ — $ — $ 6 $ 5 $ — $ — $ 5 Derivatives - asset position 76 — 76 — — — — — Derivatives - liability position (38) — (38) — (3) — (3) — Total alternative investments $ 44 $ — $ 38 $ 6 $ 2 $ — $ (3) $ 5 Other investments $ (5) $ 4 $ (9) $ — $ 2 $ 5 $ (3) $ — Subtotal $ 2,244 $ 805 $ 1,432 $ 7 $ 2,159 $ 838 $ 1,312 $ 9 Investments measured at net asset value: Hedge funds $ 212 $ 266 Private markets 392 389 Real estate 257 341 Total investments measured at net asset value $ 861 $ 996 Items to reconcile to fair value of plan assets: Pension trust payables 1 (10) (7) Total $ 3,095 $ 3,148 1. Primarily payables for investment securities purchased.
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Assumptions Used	The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs are provided below: Pension Plan Assumptions Benefit Obligations Net Periodic Costs 2020 2019 2020 2019 2018 Discount rate 2.53 % 3.29 % 3.29 % 4.32 % 3.59 % Interest crediting rate for applicable benefits 4.50 % 4.50 % 4.50 % 4.50 % 4.50 % Rate of compensation increase 4.25 % 4.25 % 4.25 % 4.25 % 4.25 % Expected return on plan assets 6.80 % 6.80 % 6.80 %
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets at Dec 31 In millions 2020 2019 Accumulated benefit obligations $ 4,200 $ 4,071 Fair value of plan assets $ 3,095 $ 3,148
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets	The following table summarizes the changes in fair value of Level 3 pension plan assets for the years ended December 31, 2020 and 2019: Fair Value Measurement of Level 3 Pension Plan Assets Equity Securities Alternative Investments Total In millions Balance at Jan 1, 2019 $ 6 $ — $ 6 Actual return on plan assets: Relating to assets held at Dec 31, 2019 — (5) (5) Purchases, sales and settlements (2) 10 8 Balance at Dec 31, 2019 $ 4 $ 5 $ 9 Actual return on plan assets: Relating to assets held at Dec 31, 2020 — 3 3 Relating to assets sold during 2020 — (4) (4) Purchases, sales and settlements (3) 2 (1) Balance at Dec 31, 2020 $ 1 $ 6 $ 7
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Assumptions Used	The weighted-average assumptions used to determine other postretirement benefit plan obligations and net periodic benefit costs for the plan are provided in the following table: Other Postretirement Benefit Plan Assumptions Benefit Obligations at Dec 31 Net Periodic Costs for the Year Ended 2020 2019 2020 2019 2018 Discount rate 2.34 % 3.17 % 3.17 % 4.23 % 3.51 % Health care cost trend rate assumed for next year 6.75 % 6.25 % 6.25 % 6.50 % 6.75 % Rate to which the cost trend rate is assumed to decline (the ultimate health care cost trend rate) 5.00 % 5.00 % 5.00 % 5.00 % 5.00 % Year that the rate reaches the ultimate health care cost trend rate 2028 2025 2025 2025 2025

LEASES_2

LEASES	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Lease, Cost [Table Text Block]	The components of lease cost for operating and finance leases for the years ended December 31, 2020 and 2019 were as follows: Lease Cost 2020 2019 In millions Operating lease cost $ 20 $ 21 Short-term lease cost 22 25 Variable lease cost 8 4 Amortization of right-of-use assets - finance 2 1 Total lease cost $ 52 $ 51
Schedule of Supplemental Cash Flow Information Related to Leases [Table Text Block]	The following table provides supplemental cash flow information related to leases: Other Lease Information 2020 2019 In millions Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 19 $ 21 Financing cash flows for finance leases $ 2 $ 1
Schedule of Lease Assets and Liabilities [Table Text Block]	The following table summarizes the lease-related assets and liabilities recorded in the consolidated balance sheets at December 31, 2020 and 2019: Lease Position Balance Sheet Classification Dec 31, 2020 Dec 31, 2019 In millions Right-of-use assets obtained in exchange for lease obligations: Operating leases 1 $ 48 $ 105 Finance leases $ 3 $ — Assets Operating lease assets Operating lease right-of-use assets $ 123 $ 89 Finance lease assets Property 15 12 Finance lease amortization Accumulated depreciation (8) (6) Total lease assets $ 130 $ 95 Liabilities Current Operating Operating lease liabilities - current $ 19 $ 16 Finance Long-term debt due within one year 2 1 Noncurrent Operating Operating lease liabilities - noncurrent 105 74 Finance Long-Term Debt 5 5 Total lease liabilities $ 131 $ 96 1. Includes $99 million for the year ended December 31, 2019 related to the adoption of Topic 842.
Lease Terms and Discount Rates [Table Text Block]	Lease Term and Discount Rate Dec 31, 2020 Dec 31, 2019 Weighted-average remaining lease term Operating leases 7.5 years 6.3 years Finance leases 3.4 years 4.5 years Weighted-average discount rate Operating leases 3.28 % 4.13 % Finance leases 3.62 % 4.22 %
Maturities of Lease Liabilities [Table Text Block]	The following table provides the maturities of lease liabilities at December 31, 2020: Maturities of Lease Liabilities Dec 31, 2020 In millions Operating Leases Finance Leases 2021 $ 23 $ 2 2022 22 2 2023 20 2 2024 19 1 2025 18 — 2026 and thereafter 38 — Total future undiscounted lease payments $ 140 $ 7 Less: Imputed interest 16 — Total present value of lease liabilities $ 124 $ 7

FAIR VALUE MEASUREMENTS_2

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table summarizes the fair value of the Corporation's financial instruments at December 31, 2020 and 2019: Fair Value of Financial Instruments 2020 2019 In millions Cost Gain Loss Fair Value Cost Gain Loss Fair Value Cash equivalents 1 $ 10 $ — $ — $ 10 $ 10 $ — $ — $ 10 Long-term debt including debt due within one year $ (393) $ — $ (120) $ (513) $ (474) $ — $ (115) $ (589) 1. Money market fund is included in "Cash and cash equivalents" in the consolidated balance sheets and held at amortized cost, which approximates fair value.

RELATED PARTY TRANSACTIONS_2

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table summarizes UCC’s transactions with TDCC and a TDCC subsidiary related to product and services agreements for the years ended December 31, 2020, 2019 and 2018: Product and Services Agreements Transactions 2020 2019 2018 Income Statement In millions Classification TDCC Subsidiary: Commodity and raw materials purchases 1 $ 1,021 $ 1,100 $ 1,600 Cost of sales Commission expense $ 22 $ 23 $ 22 Sundry income (expense) - net TDCC: General administrative and overhead type services and service fee $ 31 $ 24 $ 30 Sundry income (expense) - net Activity-based costs $ 87 $ 87 $ 85 Cost of sales 1. Period end balances on hand are included in inventory. Amounts reported for 2019 and 2018 are approximate, as reported in prior years.

BUSINESS AND GEOGRAPHIC AREAS_2

BUSINESS AND GEOGRAPHIC AREAS	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Sales are attributed to geographic regions based on customer location; long-lived assets are attributed to geographic regions based on asset location. Sales to external customers and long-lived assets by geographic region were as follows: Geographic Region Information United States Asia Pacific Rest of World Total In millions 2020 Sales to external customers 1 $ 95 $ 23 $ 11 $ 129 Long-lived assets $ 1,226 $ 20 $ 19 $ 1,265 2019 Sales to external customers 1 $ 105 $ 24 $ 9 $ 138 Long-lived assets $ 1,329 $ 18 $ 22 $ 1,369 2018 Sales to external customers 1 $ 124 $ 2 $ 10 $ 136 Long-lived assets $ 1,413 $ 10 $ 25 $ 1,448 1. Of total sales to external customers, sales in Malaysia were approximately 18 percent in 2020, 17 percent in 2019 and 1 percent in 2018, and are included in Asia Pacific.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2018
Retained earnings	$ 2,987	$ 2,922
Accounting Standards Update 2018-02 [Member]
Retained earnings			$ 254

MERGER WITH HISTORICAL DUPONT_2

MERGER WITH HISTORICAL DUPONT AND BUSINESS SEPARATION - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Feb. 15, 2019
Dow International Holdings Company [Member]
Related Party Transaction [Line Items]
Common Stock, Related Company				1,067
Ownership Interest Percentage, Related Company	4.70%	5.00%	5.00%	11.90%
The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Dividends, Paid-in-kind	$ 71
The Dow Chemical Company [Member] | Dow International Holdings Company [Member]
Related Party Transaction [Line Items]
Ownership Interest Percentage, Related Company				88.10%
Dividends, Common Stock, Stock	$ 401

REVENUE_2

REVENUE - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Percentage of revenue from product sales	98.00%	99.00%	99.00%
Contract liability	$ 40	$ 41
Accrued Liabilities [Member]
Disaggregation of Revenue [Line Items]
Contract with Customer, Liability, Current	5	4
Other Noncurrent Liabilities [Member]
Disaggregation of Revenue [Line Items]
Contract with Customer, Liability, Noncurrent	$ 35	$ 37
Maximum [Member]
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	21 years

DIVESTITURE_2

DIVESTITURE - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sales of property	$ 330	$ 21	$ 0
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		(5)
Rail Infrastructure Operations and Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	9
Proceeds from sales of property	95
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	86
Marine and Terminal Operations and Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	41
Proceeds from sales of property	226
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	185
Lease Obligation Incurred	38
Acetone Derivatives Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sales of property		17
Additional Paid-in Capital
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Adjustments to Additional Paid in Capital, Other	$ 0	$ 3	$ 0

RESTRUCTURING AND ASSET RELAT_2

RESTRUCTURING AND ASSET RELATED CHARGES - NET - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2020	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			$ 15	$ 79	$ 3
2020 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 13
2020 Restructuring Program [Member] | Accrued Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	8		8
2020 Restructuring Program [Member] | Other Noncurrent Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1		1
Employee Severance [Member] | 2020 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	9
Asset write-downs and write-offs [Member] | 2020 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 4
2017 Restructuring [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			2	4	$ 3
Payments for Restructuring			$ (19)	(16)
Restructuring Reserve				1
Fair Value, Nonrecurring [Member] | Manufacturing Assets [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges		$ 75		$ 75

SUPPLEMENTARY INFORMATION Sundr

SUPPLEMENTARY INFORMATION Sundry - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplementary Information [Line Items]
Net loss on sales of property	$ 0	$ (1)	$ 0
Gain (Loss) on Extinguishment of Debt	(19)	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(20)	(17)	(1)
Other - net	(11)	(12)	(9)
Total sundry income (expense) - net	168	(82)	(62)
Administrative and overhead fees [Member] | The Dow Chemical Company [Member]
Supplementary Information [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	(31)	(24)	(30)
Net Commission Expense [Member] | The Dow Chemical Company [Member]
Supplementary Information [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	(22)	(23)	(22)
Acetone Derivatives [Member]
Supplementary Information [Line Items]
Net loss on sales of property	0	(5)	0
Marine and Terminal Operations and Assets [Member]
Supplementary Information [Line Items]
Net loss on sales of property	185	0	0
Rail Infrastructure Operations and Assets [Member]
Supplementary Information [Line Items]
Net loss on sales of property	$ 86	$ 0	$ 0

SUPPLEMENTARY INFORMATION SUPPL

SUPPLEMENTARY INFORMATION SUPPLEMENTAL CASH FLOW INFORMATION - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Interest, net of amounts capitalized	$ 41	$ 37	$ 37
Income taxes	$ 93	$ 136	$ 269

INCOME TAXES (Schedule of Domes

INCOME TAXES (Schedule of Domestic and Foreign Components of Income Before Income Taxes and Tax Reconciliation) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Geographic Allocation of Income and Provision (Credit) for Income Taxes [Abstract]
Income (Loss) Before Income Taxes, Domestic	$ 558	$ 696	$ 1,305
Income (Loss) Before Income Taxes, Foreign	(1)	(5)	(3)
Income before income taxes	557	691	1,302
Current Federal Tax Expense (Benefit)	82	70	166
Current State and Local Tax Expense (Benefit)	2	4	6
Current Foreign Tax Expense (Benefit)	0	0	40
Current Income Tax Expense (Benefit)	84	74	212
Deferred Federal Income Tax Expense (Benefit)	42	(9)	27
Deferred State and Local Income Tax Expense (Benefit)	4	(1)	8
Deferred Income Tax Expense (Benefit)	46	(10)	35
Provision for income taxes	130	64	247
Net Income Attributable to Union Carbide Corporation	$ 427	$ 627	$ 1,055

INCOME TAXES (Reconciliation to

INCOME TAXES (Reconciliation to U.S. Statutory Rate)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Statutory U.S. federal income tax rate	21.00%	21.00%	21.00%
Unrecognized tax benefits	(0.90%)	(1.00%)	(0.30%)
Federal tax accrual adjustments	3.00%	1.70%	(0.30%)
Restoration of tax basis	0.00%	(12.20%)	0.00%
State and local tax impact	0.20%	0.90%	1.00%
Other - net	0.00%	(1.10%)	(2.40%)
Effective Tax Rate	23.30%	9.30%	19.00%

INCOME TAXES (Schedule of Defer

INCOME TAXES (Schedule of Deferred Tax Balances) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Property, Plant and Equipment	$ 22	$ 14
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards	34	39
Postretirement benefit obligations, Deferred Tax Assets	318	275
Other accruals and reserves, Deferred Tax Assets	313	320
Inventory, Deferred Tax Assets	4	5
Other - net, deferred tax assets	19	20
Subtotal, deferred tax assets	(710)	(673)
Valuation allowances, deferred tax assets	(18)	(21)
Total, deferred tax assets	692	652
Property, Deferred Tax Liabilities	194	145
Tax loss and credit carryforwards, Deferred Tax Liabilities,	0	0
Postretirement benefit obligations, Deferred Tax Liabilities	0	0
Other accruals and reserves, Deferred Tax Liabilities	4	0
Inventory, deferred tax liabilities	0	0
Other - net, deferred tax liabilities	0	0
Total, deferred tax liabilities	$ 198	$ 145

INCOME TAXES (Summary of Operat

INCOME TAXES (Summary of Operating Loss Carryforwards) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets, Operating Loss Carryforwards	$ 28	$ 33
Deferred Tax Assets, Tax Credit Carryforwards	6	6
Undistributed Earnings of Foreign Subsidiaries	7	8
Expiring Within Five Years [Member]
Deferred Tax Assets, Operating Loss Carryforwards	21	26
Expiring After Five Years or Having Indefinite Expiration [Member] [Member]
Deferred Tax Assets, Operating Loss Carryforwards	7	7
Deferred Tax Assets, Tax Credit Carryforwards	$ 6	$ 6

INCOME TAXES (Uncertain Tax Pos

INCOME TAXES (Uncertain Tax Position) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Total Gross Unrecognized Tax Benefits [Roll Forward]
Gross unrecognized tax benefits, beginning balance		$ 1	$ 1	$ 1	$ 1
Gross unrecognized tax benefits, ending balance			1	1	1
Total unrecognized tax benefits that, if recognized, would impact the effective tax rate			1	1	1
Total amount of interest and penalties (benefit) recognized in "Provision for income taxes"			$ (5)	$ (7)	$ (5)
Foreign Tax Authority [Member]
Reconciliation of Total Gross Unrecognized Tax Benefits [Roll Forward]
Increase (Decrease) in Income Taxes Payable	$ (40)	$ 40

INCOME TAXES (Tax Years Subject

INCOME TAXES (Tax Years Subject to Examination by Major Tax Jurisdiction)	12 Months Ended
	Dec. 31, 2020
Federal Income Tax [Member]
Earliest open year	2004
State and Local Income Tax [Member]
Earliest open year	2004

INVENTORIES (Schedule of Invent

INVENTORIES (Schedule of Inventories) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Finished goods	$ 157	$ 162
Work in process	23	31
Raw materials	38	47
Supplies	98	92
Total	316	332
Adjustment of inventories to a LIFO basis	(93)	(85)
Total inventories	$ 223	$ 247
Percentage of LIFO Inventory	50.00%	59.00%
Effect of LIFO Inventory Liquidation on Income	$ (2)	$ (14)

PROPERTY (Schedule of Property)

PROPERTY (Schedule of Property) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property	$ 7,089	$ 7,247
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property	$ 186	258
Land and Land Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	0 years
Land and Land Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	25 years
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property	$ 421	408
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	5 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	50 years
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property	$ 5,974	6,097
Machinery and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Machinery and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	20 years
Other property [Member]
Property, Plant and Equipment [Line Items]
Property	$ 372	357
Other property [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Other property [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	30 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property	$ 136	$ 127

PROPERTY (Schedule of Other Ite

PROPERTY (Schedule of Other Items Related to Property) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 181	$ 175	$ 179
Capitalized interest	$ 6	$ 8	$ 7

INVESTMENTS IN RELATED COMPAN_3

INVESTMENTS IN RELATED COMPANIES - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Feb. 15, 2019
Schedule of Investments [Line Items]
Investments in related companies	$ 237	$ 238
Dow International Holdings Company [Member]
Schedule of Investments [Line Items]
Ownership Interest Percentage, Related Company	5.00%	5.00%	4.70%	11.90%
Cost Method Investments	$ 232	$ 232
Dow Quimica Mexicana S.A. de C.V. [Member]
Schedule of Investments [Line Items]
Ownership Interest Percentage, Related Company	15.00%	15.00%
Cost Method Investments	$ 5	$ 5
Other [Member]
Schedule of Investments [Line Items]
Ownership Interest Percentage, Related Company	0.00%	0.00%
Cost Method Investments	$ 0	$ 1

INTANGIBLE ASSETS (Schedule of

INTANGIBLE ASSETS (Schedule of Intangible Assets) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 113	$ 112
Finite-Lived Intangible Assets, Accumulated Amortization	(97)	(90)
Finite-Lived Intangible Assets, Net	16	22
Licenses and Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	33	33
Finite-Lived Intangible Assets, Accumulated Amortization	(33)	(33)
Finite-Lived Intangible Assets, Net	0	0
Software [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	80	79
Finite-Lived Intangible Assets, Accumulated Amortization	(64)	(57)
Finite-Lived Intangible Assets, Net	$ 16	$ 22

INTANGIBLE ASSETS (Schedule o_2

INTANGIBLE ASSETS (Schedule of Amortization Expense of Intangible Assets) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Software	$ 8	$ 7	$ 6

INTANGIBLE ASSETS (Schedule o_3

INTANGIBLE ASSETS (Schedule of Future Amortization Expense of Intangible Assets) $ in Millions	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 6
2021	5
2022	2
2023	1
2024	$ 0

NOTES PAYABLE AND LONG-TERM D_3

NOTES PAYABLE AND LONG-TERM DEBT (Schedule of Notes Payable) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Notes Payable to Bank	$ 0	$ 6
Notes payable to related companies	33	32
Total notes payable	$ 33	$ 38
Year-end average interest rates	1.25%	1.88%

NOTES PAYABLE AND LONG-TERM D_4

NOTES PAYABLE AND LONG-TERM DEBT (Schedule of Long-Term Debt) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-Term Debt		$ 391	$ 391	$ 473
Unamortized debt discount and issuance costs		(3)	(3)	(4)
Long-term debt due within one year		(2)	(2)	(1)
Repayments of Long-term Debt			84	1	$ 1
Gain (Loss) on Extinguishment of Debt			$ (19)	$ 0	$ 0
Final Maturity 2023 [Member]
Debt Instrument [Line Items]
Average Interest Rate in Period			7.875%	7.875%
Long-Term Debt		129	$ 129	$ 175
Final Maturity 2025 (a) [Member]
Debt Instrument [Line Items]
Average Interest Rate in Period			6.79%	6.79%
Long-Term Debt		12	$ 12	$ 12
Final Maturity 2025 (b) [Member]
Debt Instrument [Line Items]
Average Interest Rate in Period			7.50%	7.50%
Long-Term Debt		113	$ 113	$ 150
Final Maturity 2096 [Member]
Debt Instrument [Line Items]
Average Interest Rate in Period			7.75%	7.75%
Long-Term Debt		$ 135	$ 135	$ 135
U.S. Dollar Notes [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt	$ 83
7.875 Percent Notes Due 2023 [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	46
Debt Instrument, Interest Rate, Stated Percentage		7.875%	7.875%
7.5 Percent Notes Due 2025 [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 37
Debt Instrument, Interest Rate, Stated Percentage		7.50%	7.50%
Long-term Debt [Member] | Sundry Income (Expense), Net [Member]
Debt Instrument [Line Items]
Gain (Loss) on Extinguishment of Debt		$ 19
Finance Lease Obligations [Member]
Debt Instrument [Line Items]
Long-Term Debt		$ 7	$ 7	$ 6

NOTES PAYABLE AND LONG-TERM D_5

NOTES PAYABLE AND LONG-TERM DEBT (Schedule of Annual Installments) $ in Millions	Dec. 31, 2020USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	$ 2
2021	2
2022	131
2023	1
2024	125
Letters of Credit Outstanding, Amount	$ 5

COMMITMENTS AND CONTINGENT LI_3

COMMITMENTS AND CONTINGENT LIABILITIES (Environmental Matters) (Narrative) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates	$ 55
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at Jan 1		$ 132	$ 94
Accrual adjustment		49	93
Payments against reserve		(47)	(55)
Foreign currency impact		(1)	0
Balance at Dec 31		133	132	$ 94
Environmental remediation expense		49	93	38
Capital expenditures for environmental protection		5	11	$ 9
Accrual For Environmental Loss Contingencies Superfund Sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at Jan 1		20
Balance at Dec 31		$ 18	$ 20

COMMITMENTS AND CONTINGENT LI_4

COMMITMENTS AND CONTINGENT LIABILITIES (Asbestos Related Matters) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2002
Loss Contingencies [Line Items]
Liability For Asbestos Claims Gross				$ 2,200
Percentage of Recorded Asbests Liability Related to Pending Claims		22.00%	18.00%
Percentage of Recorded Asbestos Liability Related to Future Claims		78.00%	82.00%
Liability for Asbestos Claims and Defense Costs Gross		$ 1,098	$ 1,165
Asbestos liability for defense and processing costs
Loss Contingencies [Line Items]
Asbestos Related Charges Credit	$ 1,113

COMMITMENTS AND CONTINGENT LI_5

COMMITMENTS AND CONTINGENT LIABILITIES (Asset Retirement Obligations) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Asset Retirement Obligation	$ 17	$ 14
Conditional Asset Retirement Obligations Carrying Value	$ 2	$ 2
Asset Retirement Obligation Discount rate	0.42%	2.12%

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE LOSS (Accumulated Other Comprehensive Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (1,665)	$ (1,561)
Net other comprehensive income	(105)	(104)	$ 45
Ending balance	(1,770)	(1,665)	(1,561)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(56)	(57)	(59)
Other comprehensive income (loss) before reclassifications	0	1	2
Net other comprehensive income	1	1	2
Ending balance	(55)	(56)	(57)
Pension and Other Postretirement Benefits
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,609)	(1,504)	(1,293)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(242)	(213)	(29)
Other Comprehensive Income (Loss) before Reclassifications, Tax	57	51	7
Other comprehensive income (loss) before reclassifications	(185)	(162)	(22)
Amounts reclassified from AOCL	79	57	65
Reclassification from AOCI, Current Period, Tax	(24)	(18)	(20)
Net other comprehensive income	(106)	(105)	43
Ending balance	(1,715)	(1,609)	(1,504)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amounts reclassified from AOCL	1	0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and Other Postretirement Benefits
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	103	75	85
Retained Earnings [Member] | Pension and Other Postretirement Benefits
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of stranded tax effects	$ 0	$ 0	$ (254)

PENSION PLANS AND OTHER POSTR_3

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Pension Plans) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits	$ 2
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 85
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.53%	3.29%	4.32%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.29%	4.32%	3.59%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Weighted-Average Interest Crediting Rate	4.50%	4.50%	4.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate	4.50%	4.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	4.25%	4.25%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	4.25%	4.25%	4.25%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.80%	6.80%	6.80%

PENSION PLANS AND OTHER POSTR_4

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Other Postretirement Benefits) - Other Postretirement Benefits Plan [Member]	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.34%	3.17%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.17%	4.23%	3.51%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	6.75%	6.25%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed to Calculate Net Periodic Benefit Cost, Next Fiscal Year	6.25%	6.50%	6.75%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%	5.00%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate To Calculate Net Period Benefit Cost	2028	2025
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2025	2025	2025
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate To Calculate Net Period Benefit Cost	5.00%	5.00%	5.00%

PENSION PLANS AND OTHER POSTR_5

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Change in Projected Benefit Obligation, Plan Assets and Funded Status) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 3,100	$ 3,100
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	4,229	4,097	$ 3,786
Defined Benefit Plan, Service Cost	35	34	39
Defined Benefit Plan, Interest Cost	112	145	128
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	393	453
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(281)	(280)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	(127)	(41)
Defined Benefit Plan, Plan Assets, Amount	3,095	3,148	$ 3,005
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	344	464
Defined Benefit Plan, Plan Assets, Contributions by Employer	2	2
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan	(10)	(43)
Defined Benefit Plan, Plan Assets, Benefits Paid	(281)	(280)
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(1,134)	(949)
Liability, Defined Benefit Plan, Current	(2)	(2)
Liability, Defined Benefit Plan, Noncurrent	(1,132)	(947)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(1,134)	(949)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	2,267	2,137
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	(9)	(10)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	$ 2,258	$ 2,127
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.53%	3.29%	4.32%
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ (108)	$ 0
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	220	220	$ 215
Defined Benefit Plan, Service Cost	1	1	1
Defined Benefit Plan, Interest Cost	5	7	6
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	2	12
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(8)	(15)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	0	0
Defined Benefit Plan, Plan Assets, Amount	0	0	$ 0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	0	0
Defined Benefit Plan, Plan Assets, Contributions by Employer	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan	0	0
Defined Benefit Plan, Plan Assets, Benefits Paid	0	0
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(220)	(220)
Liability, Defined Benefit Plan, Current	(15)	(17)
Liability, Defined Benefit Plan, Noncurrent	(205)	(203)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(220)	(220)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	(52)	(60)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	0	0
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	$ (52)	$ (60)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.34%	3.17%
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ 0	$ 0

PENSION PLANS AND OTHER POSTR_6

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Accumulated and Projected Benefit Obligations in Excess of Plan Assets) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	$ 4,200	$ 4,071
Defied Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	3,095	3,148
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	4,229	4,097
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	4,200	4,100
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets	$ 3,095	$ 3,148

PENSION PLANS AND OTHER POSTR_7

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Net Periodic Benefit Cost) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (20)	$ (17)	$ (1)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	35	34	39
Defined Benefit Plan, Interest Cost	112	145	128
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(200)	(210)	(218)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Defined Benefit Plan, Amortization of Gain (Loss)	110	84	95
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	56	52	43
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	1	1	1
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	(110)	(84)	(95)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	240	202	31
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	131	119	(63)
Total recognized in net periodic benefit cost and other comprehensive loss or income	187	171	(20)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	1	1	1
Defined Benefit Plan, Interest Cost	5	7	6
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	(6)	(8)	(9)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	0	0	(2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0	0	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	6	8	9
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	2	11	(2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	8	19	7
Total recognized in net periodic benefit cost and other comprehensive loss or income	$ 8	$ 19	$ 5

PENSION AND OTHER POSTRETIREMEN

PENSION AND OTHER POSTRETIREMENT BENEFITS (Estimated Future Benefit Payments) $ in Millions	Dec. 31, 2020USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	$ 287
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	263
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	260
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	257
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	254
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	1,190
Total estimated future benefit payments	2,511
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	15
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	15
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	15
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	16
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	16
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	73
Total estimated future benefit payments	$ 150

PENSION PLANS AND OTHER POSTR_8

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Plan Assets) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Defined Benefit Plan, Plan Assets, Amount	$ 3,100	$ 3,100
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	23.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	45.00%
Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	27.00%
Other Pension Plan Asset Category [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	5.00%
Defined Benefit Plan Liability, Annuity Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Concentration Risk, Percentage	31.00%

PENSION PLANS AND OTHER POSTR_9

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Basis of Fair Value Measurements) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 3,100	$ 3,100
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	3,095	3,148	$ 3,005
Defined Benefit Plan, Fair Value of Plan Assets Subtotal	2,244	2,159
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets Subtotal	805	838
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets Subtotal	1,432	1,312
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount			6
Defined Benefit Plan, Fair Value of Plan Assets Subtotal	7	9
Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	210	160
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	158	148
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	52	12
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan [Member] | U.S. Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	313	346
Pension Plan [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	313	344
Pension Plan [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	2
Pension Plan [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	343	369
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	305	325
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	37	40
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1	4
Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	656	715
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	618	669
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	37	42
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1	4	6
Pension Plan [Member] | US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	820	812
Pension Plan [Member] | US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	10	7
Pension Plan [Member] | US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	810	805
Pension Plan [Member] | US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	494	455
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	15	9
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	479	446
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	25	13
Pension Plan [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	25	13
Pension Plan [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,339	1,280
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	25	16
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,314	1,264
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	6	5
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	6	5
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	76	0
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	76	0
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	38	3
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	38	3
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Pension Plan [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	44	2
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	38	(3)
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	6	5	$ 0
Pension Plan [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	(5)	2
Pension Plan [Member] | Other [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4	5
Pension Plan [Member] | Other [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	(9)	(3)
Pension Plan [Member] | Other [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets	212	266
Pension Plan [Member] | Private Market Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets	392	389
Pension Plan [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets	257	341
Pension Plan [Member] | Plan Assets, Retirement Plan, Total investments measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	861	996
Pension Plan [Member] | Pension Trust Payables [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ (10)	$ (7)

PENSION PLANS AND OTHER POST_10

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Fair Value Measurement of Level 3 Pension Plan Assets) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 3,100	$ 3,100
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	3,095	3,148	$ 3,005
Defined Benefit Plan, Fair Value of Plan Assets Subtotal	2,244	2,159
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount			6
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held	3	(5)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchase, Sale, and Settlement	(1)	8
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold	(4)
Defined Benefit Plan, Fair Value of Plan Assets Subtotal	7	9
Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	656	715
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1	4	6
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held	0	0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchase, Sale, and Settlement	(3)	(2)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold	0
Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,339	1,280
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	44	2
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	6	5	$ 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held	3	(5)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchase, Sale, and Settlement	2	$ 10
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold	$ (4)

PENSION PLANS AND OTHER POST_11

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Defined Contribution Plans) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost	$ 7	$ 9	$ 15

LEASES_2_3

LEASES - USD ($) $ in Millions	Jan. 01, 2019	Dec. 31, 2020	Dec. 31, 2019
Operating lease cost		$ 20	$ 21
Short-term lease cost		22	25
Variable lease cost		8	4
Amortization of right-of-use assets - finance		2	1
Total lease cost		52	51
Operating cash flows for operating leases		19	21
Financing cash flows for finance leases		2	1
Right-of-use assets obtained in exchange for lease obligations:	$ 99	48	105
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability		3	0
Operating lease assets		123	89
Finance lease assets		15	12
Finance lease amortization		(5,824)	(5,878)
Total lease assets		130
Operating lease liabilities - current		19	16
Finance Lease, Liability, Current		2	1
Operating lease liabilities - noncurrent		105	74
Finance Lease, Liability, Noncurrent		5	5
Total lease liabilities		$ 131	$ 96
Operating Lease, Weighted Average Remaining Lease Term		7 years 6 months	6 years 3 months 18 days
Finance Lease, Weighted Average Remaining Lease Term		3 years 4 months 24 days	4 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent		3.28%	4.13%
Finance Lease, Weighted Average Discount Rate, Percent		3.62%	4.22%
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year		$ 23
Finance Lease, Liability, Payments, Due Next Twelve Months		2
Lessee, Operating Lease, Liability, Payments, Due Year Two		22
Finance Lease, Liability, Payments, Due Year Two		2
Lessee, Operating Lease, Liability, Payments, Due Year Three		20
Finance Lease, Liability, Payments, Due Year Three		2
Lessee, Operating Lease, Liability, Payments, Due Year Four		19
Finance Lease, Liability, Payments, Due Year Four		1
Lessee, Operating Lease, Liability, Payments, Due Year Five		18
Finance Lease, Liability, Payments, Due Year Five		0
Lessee, Operating Lease, Liability, Payments, Due after Year Five		38
Finance Lease, Liability, Payments, Due after Year Five		0
Lessee, Operating Lease, Liability, Payments, Due		140
Finance Lease, Liability, Payment, Due		7
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		16
Finance Lease, Liability, Undiscounted Excess Amount		0
Operating lease, liability		124
Finance Lease, Liability		7
Lessee, Additional Leases Not yet Commenced, Assumptions and Judgment, Amount		$ 1
Lessee, Additional Leases Not yet Commenced, Term of Contract		2 years
finance leases [Member]
Finance lease amortization		$ (8)	$ (6)
Total lease assets			$ 95
Maximum [Member]
Lessee, Operating and Finance Leases, Remaining Lease Term		20 years

FAIR VALUE MEASUREMENTS (Basis

FAIR VALUE MEASUREMENTS (Basis of Fair Value Measurements on a Recurring Basis) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	$ (393)	$ (474)
Cash and Cash Equivalents, Fair Value Disclosure	10	10
Long-term Debt, Fair Value	(513)	(589)
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	10	10
Financial Instruments Gross Unrealized Gains	0	0
Financial Instruments Gross Unrealized Loss	0	0
Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments Gross Unrealized Gains	0	0
Financial Instruments Gross Unrealized Loss	$ (120)	$ (115)

FAIR VALUE MEASUREMENTS FAIR VA

FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS (Basis of Fair Value Measurements on a Nonrecurring Basis) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019
Manufacturing Assets [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	$ 75	$ 75

RELATED PARTY TRANSACTIONS_2_3

RELATED PARTY TRANSACTIONS - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 15, 2019
Related Party Transaction [Line Items]
Payments of Dividends		$ 362	$ 570	$ 553
Additional Paid-in Capital
Related Party Transaction [Line Items]
Adjustments to Additional Paid in Capital, Other		$ 0	3	0
The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Service Fee with Parent		10.00%
Notes Receivable, Related Parties		$ 1,700	1,500
Line of Credit Facility, Maximum Borrowing Capacity		1,000
Notes Receivable, Related Parties, Noncurrent		937	937
Payments of Dividends		362	570	553
Dividends, Paid-in-kind	$ 71
The Dow Chemical Company [Member] | Net Commission Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		22	23	22
The Dow Chemical Company [Member] | Cost of Sales [Member] | Purchases from Dow [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		1,021	1,100	1,600
The Dow Chemical Company [Member] | Cost of Sales [Member] | Activity Based Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		87	87	85
The Dow Chemical Company [Member] | Estimated Federal Tax Liability, Related Party [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction		100	184	220
The Dow Chemical Company [Member] | Sundry Income (Expense), Net [Member] | Net Commission Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		22	23	22
The Dow Chemical Company [Member] | Sundry Income (Expense), Net [Member] | General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		$ 31	$ 24	$ 30
Dow International Holdings Company [Member]
Related Party Transaction [Line Items]
Stock Dividend Ownership Interest Percentage, Related Company					63.40%
Dow International Holdings Company [Member] | The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Dividends, Common Stock, Stock	$ 401

BUSINESS AND GEOGRAPHIC AREAS (

BUSINESS AND GEOGRAPHIC AREAS (Schedule of Revenue by Geographic Area and Other Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,265	$ 1,369	$ 1,448
Net trade sales	129	138	136
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,226	1,329	1,413
Net trade sales	95	105	124
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	20	18	10
Net trade sales	23	24	2
Rest of World
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	19	22	25
Net trade sales	$ 11	$ 9	$ 10
Malaysia
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Total Sales Related to a Specific Country in a Geographic Region	18.00%	17.00%	1.00%