Owens Corning (OC) 10-K 17 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 12, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	1-33100
Entity Registrant Name	Owens Corning
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	43-2109021
Entity Address, Address Line One	One Owens Corning Parkway,
Entity Address, City or Town	Toledo,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	43659
City Area Code	419
Local Phone Number	248-8000
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	OC
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 6,023,086,936
Entity Common Stock, Shares Outstanding		104,926,383
Documents Incorporated by Reference	Portions of Owens Corning’s proxy statement to be delivered to stockholders in connection with the Annual Meeting of Stockholders to be held on or about April 15, 2021 (the “2021 Proxy Statement”) are incorporated by reference into Part III hereof
Entity Central Index Key	0001370946
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Current Fiscal Year End Date	--12-31

CONSOLIDATED STATEMENTS OF EARN

CONSOLIDATED STATEMENTS OF EARNINGS (LOSS) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
NET SALES	$ 7,055	$ 7,160	$ 7,057
COST OF SALES	5,445	5,551	5,425
Gross margin	1,610	1,609	1,632
OPERATING EXPENSES
Marketing and administrative expenses	664	698	700
Science and technology expenses	82	87	89
Goodwill impairment charge	944	0	0
Other expenses, net	58	37	36
Total operating expenses	1,748	822	825
OPERATING INCOME (LOSS)	(138)	787	807
Non-operating expense (income)	(14)	34	(14)
EARNINGS (LOSS) BEFORE INTEREST AND TAXES	(124)	753	821
Interest expense, net	132	131	117
Loss on extinguishment of debt	0	32	0
EARNINGS (LOSS) BEFORE TAXES	(256)	590	704
Income tax expense	129	186	156
Equity in net earnings (loss) of affiliates	0	1	(1)
NET EARNINGS (LOSS)	(385)	405	547
Net earnings (loss) attributable to noncontrolling interests	(2)	0	2
NET EARNINGS (LOSS) ATTRIBUTABLE TO OWENS CORNING	$ (383)	$ 405	$ 545
EARNINGS (LOSS) PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS
Basic (dollars per share)	$ (3.53)	$ 3.71	$ 4.94
Diluted (dollars per share)	$ (3.53)	$ 3.68	$ 4.89
WEIGHTED AVERAGE COMMON SHARES
Basic (in shares)	108.6	109.2	110.4
Diluted (in shares)	108.6	110.1	111.4

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
NET EARNINGS (LOSS)	$ (385)	$ 405	$ 547
Currency translation adjustment (net of tax of $(4), $(4) and $(4), for the periods ended December 31, 2020, 2019 and 2018, respectively)	62	24	(123)
Pension and other postretirement adjustment (net of tax of $14, $(10), and $6, for the periods ended December 31, 2020, 2019 and 2018, respectively)	(46)	24	(19)
Hedging adjustment (net of tax of $(3), $1 and $0, for the periods ended December 31, 2020, 2019 and 2018, respectively)	6	(2)	0
COMPREHENSIVE EARNINGS (LOSS)	(363)	451	405
Comprehensive earnings (loss) attributable to noncontrolling interests	(2)	0	2
COMPREHENSIVE EARNINGS (LOSS) ATTRIBUTABLE TO OWENS CORNING	$ (361)	$ 451	$ 403

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Currency translation tax	$ (0.4)	$ (0.4)	$ (0.4)
Pension and other postretirement tax	14	(10)	6
Hedging tax	$ (3)	$ 1	$ 0

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
CURRENT ASSETS
Cash and cash equivalents		$ 717	$ 172
Receivables, less allowances of $10 at December 31, 2020 and $11 at December 31, 2019		919	770
Inventories		855	1,033
Other current assets		115	86
Total current assets		2,606	2,061
Property, plant and equipment, net		3,809	3,855
Operating lease right-of-use assets		154	203
Goodwill		989	1,932
Intangible assets, net		1,667	1,721
Deferred income taxes		28	46
Other non-current assets		228	188
TOTAL ASSETS		9,481	10,006
LIABILITIES AND EQUITY
Total current liabilities		1,440	1,329
Long-term debt, net of current portion		3,126	2,986
Pension plan liability		159	231
Other employee benefits liability		171	179
Non-current operating lease liabilities		99	138
Deferred income taxes		332	272
Other liabilities		213	200
OWENS CORNING STOCKHOLDERS’ EQUITY
Preferred stock, par value $0.01 per share	[1]	0	0
Common stock, par value $0.01 per share	[2]	1	1
Additional paid in capital		4,059	4,051
Accumulated earnings		1,829	2,319
Accumulated other comprehensive deficit		(588)	(610)
Cost of common stock in treasury	[3]	(1,400)	(1,130)
Total Owens Corning stockholders’ equity		3,901	4,631
Noncontrolling interests		40	40
Total equity		3,941	4,671
TOTAL LIABILITIES AND EQUITY		$ 9,481	$ 10,006
[1]	10 shares authorized; none issued or outstanding at December 31, 2020 and December 31, 2019
[2]	400 shares authorized; 135.5 issued and 105.6 outstanding at December 31, 2020; 135.5 issued and 109.0 outstanding at December 31, 2019
[3]	29.9 shares at December 31, 2020 and 26.5 shares at December 31, 2019

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 11	$ 16
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, authorized	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	400,000,000	400,000,000
Common stock, issued	135,500,000	135,500,000
Common stock, outstanding	109,000,000	109,500,000
Treasury stock shares	26,500,000	26,000,000

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions		Total		Common Stock Outstanding	Treasury Stock	APIC	[1]	Accumulated Earnings		AOCI		NCI
Beginning balance (in shares) at Dec. 31, 2017				111.5	24
Beginning balance at Dec. 31, 2017		$ 4,204		$ 1	$ (911)	$ 4,011		$ 1,575		$ (514)	[2]	$ 42	[3]
Increase Decrease In Stockholders Equity [Roll Forward]
Net loss attributable to Owens Corning		545						545				0	[3]
Net loss attributable to noncontrolling interests		2										2	[3]
Currency translation adjustment		(125)								(123)	[2]	(2)	[3]
Pension and other postretirement adjustment (net of tax)		(19)								(19)	[2]
Issuance of common stock under share-based payment plans (in shares)				(1)	1
Issuance of common stock under share-based payment plans		14			$ 44	(30)
Purchase of treasury stock (in shares)				3	(3)
Purchases of treasury stock		(236)			$ (236)
Stock-based compensation expense		47				47
Cumulative effect of accounting change		(12)						(12)
Dividends declared (e)		(96)						(95)	[4]
Dividends declared (e)	[3],[4]											(1)
Ending balance (in shares) at Dec. 31, 2018				109.5	26
Ending balance at Dec. 31, 2018		4,324	[4]	$ 1	$ (1,103)	4,028		2,013		(656)	[2]	41	[3]
Increase Decrease In Stockholders Equity [Roll Forward]
Net loss attributable to Owens Corning		405						405				0	[3]
Net loss attributable to noncontrolling interests		0
Currency translation adjustment		23								24	[2]	(1)	[3]
Pension and other postretirement adjustment (net of tax)		24								24	[2]
Deferred gain (loss) on hedging transactions (net of tax)		(2)								(2)	[2]
Issuance of common stock under share-based payment plans (in shares)				(0.8)	0.8
Issuance of common stock under share-based payment plans		18			$ 34	(16)
Purchase of treasury stock (in shares)				1.3	(1.3)
Purchases of treasury stock		(61)			$ (61)
Stock-based compensation expense		39				39
Dividends declared (e)	[4]	(99)						(99)
Dividends declared (e)	[3],[4]											0
Ending balance (in shares) at Dec. 31, 2019				109	26.5
Ending balance at Dec. 31, 2019		4,671		$ 1	$ (1,130)	4,051		2,319		(610)	[2]	40	[3]
Increase Decrease In Stockholders Equity [Roll Forward]
Net loss attributable to Owens Corning		(383)						(383)				0	[3]
Net loss attributable to noncontrolling interests		(2)										(2)	[3]
Currency translation adjustment		65								62	[2]	3	[3]
Pension and other postretirement adjustment (net of tax)		(46)								(46)	[2]
Deferred gain (loss) on hedging transactions (net of tax)		6								6
Issuance of common stock under share-based payment plans (in shares)				(1.1)	1.1
Issuance of common stock under share-based payment plans		15			$ 48	(33)
Purchase of treasury stock (in shares)				4.5	(4.5)
Purchases of treasury stock		(318)			$ (318)
Stock-based compensation expense		41				41
Dividends declared (e)	[4]	(108)						(107)
Dividends declared (e)	[3],[4]											(1)
Ending balance (in shares) at Dec. 31, 2020				105.6	29.9
Ending balance at Dec. 31, 2020		$ 3,941		$ 1	$ (1,400)	$ 4,059		$ 1,829		$ (588)	[2]	$ 40	[3]
[1]	Additional Paid in Capital (APIC)
[2]	Accumulated Other Comprehensive Earnings (Deficit) (“AOCI”)
[3]	Noncontrolling Interest (“NCI”)
[4]	Dividend declarations of $0.98 per share as of December 31, 2020, $0.90 per share as of December 31, 2019, and $0.85 per share as of December 31, 2018.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
NET CASH FLOW PROVIDED BY OPERATING ACTIVITIES
NET EARNINGS (LOSS)	$ (385)	$ 405	$ 547
Adjustments to reconcile net earnings (loss) to cash provided by operating activities:
Depreciation and amortization	493	457	433
Deferred income taxes	86	118	141
Provision for pension and other employee benefits liabilities	(3)	45	0
Stock-based compensation expense	41	39	47
Goodwill impairment charge	944	0	0
Intangible assets impairment charge	43	0	0
Loss on extinguishment of debt	0	32	0
Other adjustments to reconcile net earnings (loss) to cash provided by operating activities	(40)	(28)	(49)
Changes in receivables, net	(109)	19	39
Changes in inventories	189	35	(216)
Changes in accounts payable and accrued liabilities	25	(11)	(89)
Changes in other operating assets and liabilities	(11)	(10)	7
Pension fund contributions	(122)	(46)	(40)
Payments for other employee benefits liabilities	(13)	(15)	(19)
Other	(3)	(3)	2
Net cash flow provided by operating activities	1,135	1,037	803
NET CASH FLOW USED FOR INVESTING ACTIVITIES
Cash paid for property, plant and equipment	307	447	537
Derivative settlements	50	31	64
Proceeds from the sale of assets or affiliates	52	22	27
Investment in subsidiaries and affiliates, net of cash acquired	0	0	(1,143)
Net cash flow used for investing activities	(205)	(394)	(1,589)
NET CASH FLOW (USED FOR) PROVIDED BY FINANCING ACTIVITIES
Proceeds from senior revolving credit and receivables securitization facilities	876	2,172	1,954
Payments on senior revolving credit and receivables securitization facilities	(876)	(2,248)	(1,879)
Proceeds from term loan borrowing	0	0	600
Payments on term loan borrowing	(200)	(300)	(100)
Proceeds from long-term debt	297	445	389
Payments on long-term debt	0	(484)	0
Dividends paid	(104)	(95)	(92)
Net (decrease) increase in short-term debt	(19)	4	16
Purchases of treasury stock	(318)	(61)	(236)
Other	(14)	(6)	(5)
Net cash flow (used for) provided by financing activities	(358)	(573)	647
Effect of exchange rate changes on cash	(27)	24	(29)
Net increase (decrease) in cash, cash equivalents and restricted cash	545	94	(168)
Cash, cash equivalents and restricted cash at beginning of period	179	85	253
Cash, cash equivalents and restricted cash at end of period	724	179	85
Cash paid during the year for income taxes	78	58	91
Cash paid during the year for interest	$ 135	$ 131	$ 158

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividend (dollars per share)	$ 0.98	$ 0.90	$ 0.85

BUSINESS AND SUMMARY OF SIGNIFI

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Description of Business Owens Corning, a Delaware corporation, is a global building and construction materials leader that manufactures and delivers a broad range of high-quality insulation, roofing and fiberglass composite materials. The Company operates within three segments: Composites, Insulation and Roofing. Through these lines of business, Owens Corning manufactures and sells products worldwide. The Company maintains leading market positions in many of its major product categories. General On February 4, 2021, the Board of Directors declared a quarterly dividend of $0.26 per common share payable on April 2, 2021 to shareholders of record as of March 5, 2021. Basis of Presentation Unless the context requires otherwise, the terms “Owens Corning,” “Company,” “we” and “our” in these notes refer to Owens Corning and its subsidiaries. The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States. Principles of Consolidation The Consolidated Financial Statements of the Company include the accounts of majority-owned subsidiaries. Intercompany accounts and transactions are eliminated. Reclassifications Certain reclassifications have been made to the 2019 and 2018 Consolidated Financial Statements and Notes to the Consolidated Financial Statements to conform to the classifications used in 2020. Use of Estimates and Assumptions The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and 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. Actual results could differ materially from those estimates. Revenue Recognition We recognize revenue as the amount of consideration that we expect to receive in exchange for transferring promised goods or services to customers. We do not adjust the transaction price for the effects of a significant financing component, as the time period between control transfer of goods and services and expected payment is one year or less. At the time of sale, we estimate provisions for different forms of variable consideration (discounts, rebates, returns and other refund liabilities) based on historical experience, current conditions and contractual obligations, as applicable. The estimated transaction price is typically not subject to significant reversals. We adjust these estimates when the most likely amount of consideration we expect to receive changes, although these changes are typically minor. Sales, value-added and other similar taxes that we collect are excluded from revenue. Many of our customer volume commitments are short-term and our performance obligations are generally limited to single purchase orders. Substantially all of our revenue is recognized at a point-in-time when control of goods transfers to the customer. Control transfer typically occurs when goods are shipped from our facilities or at other predetermined control transfer points (for instance, destination terms or consignment arrangements). Revenue Recognition (continued) We typically do not satisfy performance obligations without obtaining an unconditional right to payment from customers and, therefore, do not carry contract asset balances on the Consolidated Balance Sheets. Contract liability balances are recorded separately from receivables on the Consolidated Balance Sheets in either Total current liabilities or Other liabilities, depending on the timing of performance obligation satisfaction. We sell separately-priced warranties that extend certain product and workmanship coverages beyond our standard product warranty, which is described in Note 9. The up-front consideration on extended warranty contracts is deferred and recognized as revenue over time, based on the respective coverage period, ranging from 16 to 20 years. On an annual basis, we expect to recognize approximately $4 million of revenue associated with these extended warranty contracts. Additionally, in certain limited cases, we receive consideration before goods or services are transferred to the customer. These customer down payments and deposits are deferred, and typically recognized as revenue in the following quarter when we satisfy the related performance obligations. As of December 31, 2019, our contract liability balances (for extended warranties, down payments and deposits, collectively) totaled $60 million, of which $19 million was recognized as revenue throughout 2020. As of December 31, 2020, our contract liability balances totaled $66 million. As a practical expedient, we recognize incremental costs of obtaining a contract, if any, as an expense when incurred if the amortization period of the asset would have been one year or less. We do not have any costs to obtain or fulfill a contract that are capitalized under Accounting Standard Codification (ASC) 606. Cost of Sales Cost of sales includes material, labor, energy and manufacturing overhead costs, including depreciation and amortization expense associated with the manufacture and distribution of the Company’s products. Provisions for warranties are provided in the same period that the related sales are recorded and are based on historical experience, current conditions and contractual obligations, as applicable. Distribution costs include inbound freight costs; purchasing and receiving costs; inspection costs; warehousing costs; shipping and handling costs, which include costs incurred relating to preparing, packaging, and shipping products to customers; and other costs of the Company’s distribution network. We account for shipping and handling activities that occur after control of the related good transfers as fulfillment activities instead of performance obligations. All shipping and handling costs billed to the customer are included as net sales in the Consolidated Statements of Earnings (Loss). Marketing and Advertising Expenses Marketing and advertising expenses are included in Marketing and administrative expenses. These costs include advertising and marketing communications, which are expensed the first time the advertisement takes place. Marketing and advertising expenses for the years ended December 31, 2020, 2019 and 2018 were $98 million, $117 million and $120 million, respectively. Science and Technology Expenses The Company incurs certain expenses related to science and technology. These expenses include salaries, building and equipment costs, utilities, administrative expenses, materials and supplies associated with the improvement and development of the Company’s products and manufacturing processes. These costs are expensed as incurred. Earnings per Share Basic earnings (loss) per share are computed using the weighted-average number of common shares outstanding during the period. Diluted earnings (loss) per share reflect the dilutive effect of common equivalent shares and increased shares that would result from the conversion of equity securities. The effects of anti-dilution are not presented. Cash, Cash Equivalents and Restricted Cash The Company defines cash and cash equivalents as cash and time deposits with maturities of three months or less when purchased. On the Consolidated Statements of Cash Flows, the total of Cash, cash equivalents and restricted cash includes restricted cash of $7 million as of December 31, 2020, 2019 and 2018. Restricted cash primarily represents amounts received from a counterparty related to its performance assurance on an executory contract, and is included in Other current assets on the Consolidated Balance Sheets. These amounts are contractually required to be set aside, and the counterparty can exchange the cash for another form of performance assurance at its discretion. Accounts Receivable Trade accounts receivable are recorded at the invoiced amount and do not bear interest. Consistent with the requirements of ASU 2016-13, "Financial Instruments - Credit Losses (Topic 236)," the allowance for doubtful accounts is based on the Company’s assessment of the collectability of customer accounts. The Company regularly reviews the allowance by considering factors such as historical experience, credit quality, the age of the accounts receivable balances, and current economic conditions that may affect a customer’s ability to pay. Account balances are charged off against the allowance when the Company believes it is probable the receivable will not be recovered. Inventory Valuation Inventory costs include material, labor, and manufacturing overhead costs, including depreciation and amortization expense associated with the manufacture and distribution of the Company’s products. Inventories are stated at lower of cost or net realizable value and expense estimates are made for excess and obsolete inventories. Cost is determined by the first-in, first-out (“FIFO”) method. Investments in Affiliates The Company accounts for investments in affiliates of 20% to 50% ownership when the Company does not have a controlling financial interest using the equity method under which the Company’s share of earnings and losses of the affiliate is reflected in earnings, and dividends are credited against the investment in affiliate when declared. Investments in affiliates are recorded in Other non-current assets on the Consolidated Balance Sheets and as of December 31, 2020 and 2019, the total value of investments was $51 million. Goodwill and Other Intangible Assets Goodwill assets are not amortized but are tested for impairment on at least an annual basis. In the current year, as part of the annual assessment, the Company used both a qualitative and quantitative approach to determine whether the fair value of a reporting unit was less than its carrying amount. Events and circumstances we consider in performing the qualitative assessment include macro-economic conditions, market and industry conditions, internal cost factors, and the overall financial performance of the reporting units. As part of our quantitative testing process for goodwill, the Company estimates fair values using a discounted cash flow approach from the perspective of a market participant. Significant assumptions used in the discounted cash flow approach are revenue growth rates and earnings before interest and taxes ("EBIT") margins used in estimating discrete period cash flow forecasts of the reporting unit, the discount rate, and the long-term revenue growth rate and EBIT margins used in estimating the terminal business value. The cash flow forecasts of the reporting units are based upon management’s long-term view of our markets and are the forecasts that are used by senior management and the Board of Directors to evaluate operating performance. The discount rate utilized is management’s estimate of what the market’s weighted average cost of capital is for a company with a similar debt rating and stock volatility, as measured by beta. The terminal business value is determined by applying the long-term growth rate to the latest year for which a forecast exists. As part of our goodwill quantitative testing process, we would evaluate whether there are reasonably likely changes to management’s estimates that would have a material impact on the results of the goodwill impairment testing. Other indefinite-lived intangible assets are not amortized but are tested for impairment on at least an annual basis or when determined to have a finite useful life. Substantially all of the indefinite-lived intangible assets are in trademarks and trade names. The Company uses the royalty relief approach to determine whether it is more likely than not that the fair value of these assets is less than its carrying amount. This review is performed annually, or when circumstances arise which indicate there may be impairment. When applying the royalty relief approach, the Company performs a discounted cash flow analysis based on the value derived from owning these trademarks and trade names and being relieved from paying royalty to third parties. Significant assumptions used include the discrete period revenue growth rates, royalty rates, discount rates, and terminal value. The inputs for the goodwill and indefinite-lived intangible tests are considered Level 3 inputs under the fair value hierarchy as they are the Company’s own data, and are unobservable in the marketplace. Indefinite-lived intangible assets purchased through acquisition are generally tested qualitatively for impairment in the first year following the acquisition before transitioning to the standard methodology described herein in subsequent years. Properties and Depreciation Property, plant and equipment are stated at cost and depreciated over their estimated useful lives using the straight-line method. Property, plant and equipment accounts are relieved of the cost and related accumulated depreciation when assets are disposed of or otherwise retired. Precious metals used in our production tooling are included in property, plant and equipment and are depleted as they are consumed during the production process. Depletion typically represents an annual expense of less than 3% of the outstanding value and is recorded in Cost of sales on the Consolidated Statements of Earnings (Loss). The range of useful lives for the major components of the Company’s plant and equipment is as follows: Buildings and leasehold improvements 15 – 40 years Machinery and equipment Furnaces 4 – 15 years Information systems 5 – 10 years Equipment 5 – 20 years Expenditures for normal maintenance and repairs are expensed as incurred. Asset Impairments The Company evaluates tangible and intangible long-lived assets for impairment when triggering events have occurred. This requires significant assumptions including projected cash flows, projected income tax rate and terminal business value. These inputs are considered Level 3 inputs under the fair value hierarchy as they are the Company’s own data, and are unobservable in the marketplace. Changes in management intentions, market conditions or operating performance could indicate that impairment charges might be necessary that could be material to the Company’s Consolidated Financial Statements in any given period. Please refer to Note 5 for additional detail on impairment charges recorded in 2020. Income Taxes The Company recognizes current tax liabilities and assets for the estimated taxes payable or refundable on the tax returns for the current year. Deferred tax balances reflect the impact of temporary differences between the carrying amount of assets and liabilities and their tax basis. Amounts are stated at enacted tax rates expected to be in effect when taxes are actually paid or recovered. In addition, realization of certain deferred tax assets is dependent upon our ability to generate future taxable income. The Company records a valuation allowance to reduce its deferred tax assets to the amount that it believes is more likely than not to be realized. In addition, the Company estimates tax reserves to cover potential taxing authority claims for income taxes and interest attributable to audits of open tax years. Taxes Collected from Customers and Remitted to Government Authorities and Taxes Paid to Vendors Taxes are assessed by various governmental authorities at different rates on many different types of transactions. The Company charges sales tax or value-added tax (VAT) on sales to customers where applicable, as well as captures and claims back all available VAT that has been paid on purchases. VAT is recorded in separate payable or receivable accounts and does not affect revenue or cost of sales line items in the income statement. VAT receivable is recorded as a percentage of qualifying purchases at the time the vendor invoice is processed. VAT payable is recorded as a percentage of qualifying sales at the time an Owens Corning sale to a customer subject to VAT occurs. Amounts are paid to the taxing authority according to the method and collection prescribed by local regulations. Where applicable, VAT payable is netted against VAT receivable. The Company also pays sales tax to vendors who include a tax, required by government regulations, to the purchase price charged to the Company. Pension and Other Postretirement Benefits Accounting for pensions and other postretirement benefits involves estimating the cost of benefits to be provided well into the future and attributing that cost over the time period each employee works. To accomplish this, extensive use is made of assumptions about investment returns, discount rates, inflation, mortality, turnover and medical costs. Derivative Financial Instruments The Company recognizes all derivative instruments as either assets or liabilities at fair value on the balance sheet. Please refer to Note 4 for further disclosure on derivatives. The Company performs an analysis for effectiveness of its derivatives designated as hedging instruments at the end of each quarter based on the terms of the contracts and the underlying items being hedged. The change in the fair value of cash flow hedges is deferred in Accumulated other comprehensive income (deficit) ("AOCI") and is subsequently recognized in Cost of sales (for commodity and foreign currency cash flow hedges) on the Consolidated Statements of Earnings (Loss) in order to mirror the location of the hedged items impacting earnings. Cash settlements for commodity and foreign currency hedges qualifying as cash flow hedges are included in Operating activities in the Consolidated Statements of Cash Flows. The Company has translation exposure resulting from translating the financial statements of foreign subsidiaries into U.S. Dollars, which is recognized in Currency translation adjustment (a component of AOCI). The Company uses cross-currency forward contracts to hedge a portion of the net investment in foreign subsidiaries against fluctuations in foreign exchange rates. The changes in fair values of these derivative instruments are recognized in Currency translation adjustment (a component of AOCI), with recognition of the excluded components amortized to Interest expense, net on the Consolidated Statements of Earnings (Loss). Cash settlements for derivatives qualifying as net investment hedges are included in Investing activities in the Consolidated Statements of Cash Flows. The Company uses forward currency exchange contracts to manage existing exposures to foreign exchange risk related to assets and liabilities recorded on the Consolidated Balance Sheets. Gains and losses resulting from the changes in fair value of these instruments are recorded in Other expenses, net on the Consolidated Statements of Earnings (Loss), and are substantially offset by net revaluation impacts on foreign currency denominated balance sheet exposures (which are also recorded in Other expenses, net). Cash settlements for non-designated derivatives are included in the Consolidated Statements of Cash Flows in the category that is consistent with the nature of the derivative instrument, which is generally the same category as the underlying item being hedged. Fair Value Measurements The carrying value of cash and cash equivalents, accounts receivable and short-term debt approximate fair value because of the short-term maturity of the instruments. The Company uses widely accepted valuation tools to determine fair value of our derivatives, such as discounting cash flows to calculate a present value for the derivatives. Our derivatives consist of natural gas forward swaps, cross currency swaps and foreign exchange forward contracts, all of which are over-the-counter and not traded through an exchange. The models use Level 2 inputs, such as forward curves and other commonly quoted observable transactions and prices. The fair value of our derivatives and hedging instruments are all classified as Level 2 investments within the three-tier hierarchy. Please refer to Notes 4 and 11 for additional fair value disclosure of derivative financial instruments and long-term debt, respectively. Foreign Currency The functional currency of the Company’s subsidiaries is generally the applicable local currency. Assets and liabilities of foreign subsidiaries are translated into United States Dollars at the period-end rate of exchange, and their Statements of Earnings and Statements of Cash Flows are converted on an ongoing basis at the monthly average rate. The resulting translation adjustment is included in AOCI in the Consolidated Balance Sheets and Consolidated Statements of Stockholders’ Equity. Transaction gains and losses that arise from exchange rate fluctuations on transactions denominated in a currency other than the functional currency are recorded in Other expenses, net in the Consolidated Statements of Earnings (Loss) as incurred. As discussed in the Derivative Financial Instruments section above, the Company uses non-designated foreign currency derivative financial instruments to mitigate this risk. The Company recorded foreign currency transactional gains (net of associated derivative activity) of $6 million, $12 million and $7 million during the years ended December 31, 2020, 2019, and 2018, respectively. Please refer to Note 4 for additional disclosures related to non-designated derivatives. Accounting Pronouncements The following table summarizes recent accounting standard updates (ASU) issued by the Financial Accounting Standards Board (FASB) that could have an impact on the Company's Consolidated Financial Statements: Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Recently adopted standards: ASU 2018-14 "Compensation- Retirement Benefits- Defined Benefit Plans- General (Subtopic 715-20) This standard modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. January 1, 2020 We adopted this guidance using the retrospective approach for the year ended December 31, 2020. The adoption of this guidance did not have a material effect on our consolidated financial statements. Please refer to Notes 12 and 13 for relevant disclosure requirements. ASU 2016-13 "Financial Instruments - Credit Losses (Topic 326)," as amended by ASU 2018-19, 2019-04, 2019-05, 2019-10, 2019-11, and 2020-02 This standard replaces the incurred loss methodology for recognizing credit losses with a current expected credit losses model and applies to all financial assets, including trade receivables. Entities will adopt the standard using a modified-retrospective approach. January 1, 2020 We adopted this standard using the modified-retrospective approach in the first quarter of 2020. The adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to the Accounts Receivable paragraph above in Note 1 of the Consolidated Financial Statements for additional detail on our accounting policy. ASU 2017-04 "Intangibles - Goodwill and Other (Topic 350)" This standard simplifies the test for goodwill impairment by eliminating Step 2 of the impairment test. If the carrying amount of a reporting unit exceeds its fair value, an impairment loss shall be recognized in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. Entities will adopt the standard using a prospective approach. January 1, 2020 We adopted this standard using the prospective approach for our interim impairment test conducted in the first quarter of 2020. The goodwill impairment charge of $944 million recorded for the year ended December 31, 2020, was calculated in accordance with this standard. Please refer to Note 5 of the Consolidated Financial Statements for additional detail on this adoption. ASU 2016-02, "Leases (Topic 842)," as amended by ASU 2017-13, 2018-01, 2018-10, 2018-11, 2019-01, 2019-10, 2020-02 and 2020-05 The standard requires lessees to recognize a right-of-use asset and lease liability for all leases with terms of more than 12 months. The recognition and presentation of expenses will depend on classification as a finance or operating lease. Entities may elect to apply the provisions of the new leasing standard on January 1, 2019, without adjusting the comparative periods presented by recognizing a cumulative-effect adjustment to the opening balance of retained earnings. January 1, 2019 We adopted this standard using the optional transition method in the first quarter of 2019. Please refer to Note 7 of the Consolidated Financial Statements for ongoing disclosure requirements. Recently issued standards: ASU 2019-12 "Income Taxes (Topic 740)" This standard simplifies accounting for income taxes including such topics as intraperiod tax allocations, franchise taxes and separate company financial statements. January 1, 2021 We do not expect the adoption of this standard to have a material effect on our consolidated financial statements.

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
SEGMENT INFORMATION	The Company has three reportable segments: Composites, Insulation and Roofing. Accounting policies for the segments are the same as those for the Company. The Company’s three reportable segments are defined as follows: Composites – The Company manufactures, fabricates and sells glass reinforcements in the form of fiber. Glass reinforcement materials are also used downstream by the Composites segment to manufacture and sell glass fiber products in the form of fabrics, non-wovens and other specialized products. Insulation – Within our Insulation segment, the Company manufactures and sells fiberglass insulation into residential, commercial, industrial and other markets for both thermal and acoustical applications. It also manufactures and sells glass fiber pipe insulation, flexible duct media, bonded and granulated mineral wool insulation, cellular glass insulation and foam insulation used in above- and below-grade construction applications. Roofing – Within our Roofing segment, the Company manufactures and sells residential roofing shingles, oxidized asphalt materials, roofing components used in residential and commercial construction and specialty applications, and synthetic packaging materials. NET SALES The following tables show a disaggregation of our net sales by segment and geographic region (in millions). Corporate eliminations (shown below) largely reflect intercompany sales from Composites to Roofing. External customer sales are attributed to geographic region based upon the location from which the product is sold to the external customer. Twelve Months Ended December 31, 2020 Reportable Segments Composites Insulation Roofing Eliminations Consolidated Disaggregation Categories U.S. residential $ 272 $ 949 $ 2,450 $ (204) $ 3,467 U.S. commercial and industrial 538 603 133 — 1,274 Total United States 810 1,552 2,583 (204) 4,741 Europe 524 609 14 (1) 1,146 Asia-Pacific 495 158 11 — 664 Rest of world 131 288 87 (2) 504 NET SALES $ 1,960 $ 2,607 $ 2,695 $ (207) $ 7,055 Twelve Months Ended December 31, 2019 Reportable Segments Composites Insulation Roofing Eliminations Consolidated Disaggregation Categories U.S. residential $ 269 $ 927 $ 2,375 $ (195) $ 3,376 U.S. commercial and industrial 614 643 143 — 1,400 Total United States 883 1,570 2,518 (195) 4,776 Europe 572 625 13 (1) 1,209 Asia-Pacific 475 176 13 — 664 Rest of world 129 297 90 (5) 511 NET SALES $ 2,059 $ 2,668 $ 2,634 $ (201) $ 7,160 Twelve Months Ended December 31, 2018 Reportable Segments Composites Insulation Roofing Eliminations Consolidated Disaggregation Categories U.S. residential $ 263 $ 990 $ 2,199 $ (177) $ 3,275 U.S. commercial and industrial 598 625 161 (12) 1,372 Total United States 861 1,615 2,360 (189) 4,647 Europe 590 605 14 — 1,209 Asia-Pacific 464 178 15 (1) 656 Rest of world 126 322 103 (6) 545 NET SALES $ 2,041 $ 2,720 $ 2,492 $ (196) $ 7,057 Our contracts with customers are broadly similar in nature throughout our reportable segments, but the amount, timing and uncertainty of revenue and cash flows may vary in each reportable segment due to geographic and end-market economic factors. In the United States, sales are primarily related to the residential housing market and commercial and industrial applications. Residential market demand is driven by housing starts and repair and remodeling activity (influenced by existing home sales, seasonal home improvement and damage from major storms). Significant portions of our residential products across our three reportable segments are used interchangeably in both new construction and repair and remodeling, and our customers typically distribute (or use) the products for both applications. U.S. commercial and industrial revenues are largely driven by U.S. industrial production growth, commercial construction activity and overall economic conditions in the U.S. Outside of the United States (Europe, Asia-Pacific and Rest of world), sales are primarily related to commercial and industrial applications and, to a lesser extent, residential applications in certain countries. Throughout the international regions, demand is primarily driven by industrial production growth, commercial construction activity and overall economic conditions in each respective geographical region. EARNINGS BEFORE INTEREST AND TAXES Earnings (loss) before interest and taxes (EBIT) by segment consists of net sales less related costs and expenses and are presented on a basis that is used internally for evaluating segment performance. Certain items, such as general corporate expenses or income and certain other expense or income items, are excluded from the internal evaluation of segment performance. Accordingly, these items are not reflected in EBIT for our reportable segments and are included within Corporate, Other and Eliminations. The following table summarizes EBIT by segment (in millions): Twelve Months Ended December 31, 2020 2019 2018 Reportable Segments Composites $ 165 $ 247 $ 251 Insulation 250 230 290 Roofing 591 455 434 Total reportable segments 1,006 932 975 Restructuring costs (41) (28) (22) Gains on sale of certain precious metals 26 — — Goodwill impairment charge (944) — — Intangible assets impairment charge (43) — — Acquisition-related costs — — (16) Recognition of acquisition inventory fair value step-up — — (2) Pension settlement losses — (43) — Environmental liability charges — (4) — General corporate expense and other (128) (104) (114) Total Corporate, other and eliminations (1,130) (179) (154) EBIT $ (124) $ 753 $ 821 TOTAL ASSETS AND PROPERTY, PLANT AND EQUIPMENT The following table summarizes total assets by segment and property, plant and equipment by geographic region (in millions): December 31, TOTAL ASSETS 2020 2019 Reportable Segments Composites $ 2,426 $ 2,470 Insulation 3,937 4,975 Roofing 1,814 1,784 Total reportable segments 8,177 9,229 Cash and cash equivalents 717 172 Noncurrent deferred income taxes 28 46 Investments in affiliates 51 51 Assets held for sale 5 1 Corporate property, plant and equipment, other assets and eliminations 503 507 CONSOLIDATED TOTAL ASSETS $ 9,481 $ 10,006 December 31, PROPERTY, PLANT AND EQUIPMENT BY GEOGRAPHIC REGION 2020 2019 United States $ 2,169 $ 2,204 Europe 777 762 Asia-Pacific 594 601 Rest of world 269 288 TOTAL PROPERTY, PLANT AND EQUIPMENT $ 3,809 $ 3,855 PROVISION FOR DEPRECIATION AND AMORTIZATION The following table summarizes the provision for depreciation and amortization by segment (in millions): Twelve Months Ended December 31, 2020 2019 2018 Reportable Segments Composites $ 159 $ 154 $ 147 Insulation 201 194 186 Roofing 59 54 51 Total reportable segments 419 402 384 General corporate depreciation and amortization (a) 74 55 49 CONSOLIDATED PROVISION FOR DEPRECIATION AND AMORTIZATION $ 493 $ 457 $ 433 (a) In 2020, 2019 and 2018, General corporate depreciation and amortization expense included $20 million, $9 million and $10 million, respectively, of accelerated depreciation related to restructuring actions further explained in Note 10 to the Consolidated Financial Statements. ADDITIONS TO PROPERTY, PLANT AND EQUIPMENT The following table summarizes additions to property, plant and equipment on an accrual basis by segment (in millions): Twelve Months Ended December 31, 2020 2019 2018 Reportable Segments Composites $ 105 $ 123 $ 154 Insulation 132 210 240 Roofing 46 56 91 Total reportable segments 283 389 485 General corporate additions 37 62 57 CONSOLIDATED ADDITIONS TO PROPERTY, PLANT AND EQUIPMENT $ 320 $ 451 $ 542

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories consist of the following (in millions): December 31, 2020 2019 Finished goods $ 532 $ 715 Materials and supplies 323 318 Total inventories $ 855 $ 1,033

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	DERIVATIVE FINANCIAL INSTRUMENTS The Company is exposed to, among other risks, the impact of changes in commodity prices, foreign currency exchange rates, and interest rates in the normal course of business. The Company’s risk management program is designed to manage the exposure and volatility arising from these risks, and utilizes derivative financial instruments to offset a portion of these risks. The Company uses derivative financial instruments only to the extent necessary to hedge identified business risks, and does not enter into such transactions for trading purposes. The Company generally does not require collateral or other security with counterparties to these financial instruments and is therefore subject to credit risk in the event of nonperformance; however, the Company monitors credit risk and currently does not anticipate nonperformance by other parties. Contracts with counterparties generally contain right of offset provisions. These provisions effectively reduce the Company’s exposure to credit risk in situations where the Company has gain and loss positions outstanding with a single counterparty. It is the Company’s policy to offset on the Consolidated Balance Sheets the amounts recognized for derivative instruments with any cash collateral arising from derivative instruments executed with the same counterparty under a master netting agreement. As of December 31, 2020 and 2019, the Company did not have any amounts on deposit with any of its counterparties, nor did any of its counterparties have any amounts on deposit with the Company. Derivative Fair Values Our derivatives consist of natural gas forward swaps, cross-currency swaps, foreign exchange forward contracts and U.S. treasury rate lock agreements, all of which are over-the-counter and not traded through an exchange. The Company uses widely accepted valuation tools to determine fair value, such as discounting cash flows to calculate a present value for the derivatives. The models use Level 2 inputs, such as forward curves and other commonly quoted observable transactions and prices. The fair value of our derivatives and hedging instruments are all classified as Level 2 investments within the three-tier hierarchy. The following table presents the fair value of derivatives and hedging instruments and the respective location on the Consolidated Balance Sheets (in millions): Fair Value at Location December 31, 2020 December 31, 2019 Derivative assets designated as hedging instruments: Net investment hedges: Cross currency swaps Other current assets $ 5 $ 12 Cross currency swaps Other non-current assets $ — $ 1 Cash flow hedges: Natural gas forward swaps Other current assets $ 2 $ — Treasury interest rate lock Other non-current assets $ 4 $ — Derivative liabilities designated as hedging instruments: Net investment hedges: Cross-currency swaps Other liabilities $ 11 $ 4 Cash flow hedges: Natural gas forward swaps Total current liabilities $ — $ 3 Derivative assets not designated as hedging instruments: Foreign exchange forward contracts Other current assets $ 2 $ 9 Derivative liabilities not designated as hedging instruments: Foreign exchange forward contracts Total current liabilities $ 45 $ 1 Consolidated Statements of Earnings (Loss) Activity The following table presents the impact and respective location of derivative activities on the Consolidated Statements of Earnings (Loss) (in millions): Twelve Months Ended Location 2020 2019 2018 Derivative activity designated as hedging instruments: Natural gas cash flow hedges: Amount of loss/(gain) reclassified from AOCI (as defined below) into earnings (a) Cost of sales $ 5 $ 4 $ (2) Cross-currency swap net investment hedges: Amount of gain recognized in earnings on derivative amounts excluded from effectiveness testing Interest expense, net $ (8) $ (13) $ (12) Derivative activity not designated as hedging instruments: Foreign currency: Amount of (gain)/loss recognized in earnings (b) Other expenses, net $ 41 $ (35) $ (55) (a) Accumulated Other Comprehensive Earnings (Deficit) ("AOCI") (b) (Gains)/losses related to foreign currency derivatives were substantially offset by net revaluation impacts on foreign currency denominated balance sheet exposures, which were also recorded in Other expenses, net. Please refer to the "Other Derivatives" section below for additional detail. Consolidated Statements of Comprehensive Earnings (Loss) Activity The following table presents the impact of derivative activities on the Consolidated Statements of Comprehensive Earnings (Loss) (in millions): Amount of (Gain) Loss Recognized in Comprehensive Earnings (Loss) Twelve Months Ended December 31, Hedging Type Derivative Financial Instrument 2020 2019 Net investment hedge Cross-currency swaps $ (15) $ (18) Cash flow hedge Natural gas forward swaps $ (5) $ 2 Cash flow hedge Treasury interest rate lock $ (4) $ — Net Investment Hedges The Company has translation exposure resulting from translating the financial statements of foreign subsidiaries into U.S. Dollars, which is recognized in Currency translation adjustment (a component of AOCI). The Company uses cross-currency forward contracts to hedge portions of the net investment in foreign subsidiaries against fluctuations in foreign exchange rates. As of December 31, 2020, the notional amount of these derivative financial instruments was $218 million related to the U.S Dollar and European Euro. In the second quarter of 2020, the Company unwound certain net investment hedge contracts, resulting in cash proceeds of $30 million. Cash Flow Hedges The Company uses a combination of derivative financial instruments, which qualify as cash flow hedges, and physical contracts to manage forecasted exposure to electricity and natural gas prices. As of December 31, 2020, the notional amounts of these natural gas forward swaps was 2 million MMBTu (or MMBTu equivalent based on U.S. and European indices), which is in line with the notional amounts at December 31, 2019. In March 2020, the Company entered into a $175 million forward U.S. Treasury rate lock agreement to manage the U.S. Treasury portion of its interest rate risk associated with the anticipated issuance of certain 10-year fixed rate senior notes before the end of 2022. The Company intends to cash settle this agreement upon a future issuance of certain senior notes thereby effectively locking in the U.S. Treasury fixed interest rate in effect at the time the agreement was initiated. The locked fixed rate of this agreement is 0.994%. The Company has designated this outstanding forward U.S. Treasury rate lock agreement, which expires on December 15, 2022, as a cash flow hedge. Other Derivatives The Company uses forward currency exchange contracts to manage existing exposures to foreign exchange risk related to assets and liabilities recorded on the Consolidated Balance Sheets. As of December 31, 2020, the Company had notional amounts of $729 million for non-designated derivative financial instruments related to foreign currency exposures in U.S. Dollars primarily related to Brazilian Real, Chinese Yuan, European Euro, Hong Kong Dollar, Indian Rupee, and South Korean Won. In addition, the Company had notional amounts of $198 million for non-designated derivative financial instruments related to foreign currency exposures in European Euro primarily related to the Polish Zloty and Russian Ruble.

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS The Company tests goodwill and indefinite-lived intangible assets for impairment as of October 1 st each year, or more frequently should circumstances change or events occur that would more likely than not reduce the fair value of a reporting unit below its carrying amount. Goodwill First Quarter of 2020 Impairment Charge During the first quarter of 2020, the Company’s significant share price reduction during the ongoing COVID-19 pandemic was determined to be an indicator of impairment under ASC 350. As of the end of the first quarter, the COVID-19 pandemic was expected to have a negative impact on results for the remainder of 2020 and create near-term uncertainty in our markets. As of our prior year annual goodwill impairment testing date (October 1, 2019), testing indicated that the business enterprise value for the Insulation reporting unit exceeded its carrying value by approximately 10%. There was uncertainty surrounding the macroeconomic factors impacting this reporting unit and a downturn in these factors or a change in the long-term revenue growth or profitability for this reporting unit could increase the likelihood of a future impairment. In the first quarter of 2020, the Company performed its ongoing assessment to consider whether events or circumstances had occurred that could more likely than not reduce the fair value of a reporting unit below its carrying value. The valuation limitation from the Company’s share price decline in the first quarter of 2020, the narrow cushion on the Insulation reporting unit and the high level of near-term macroeconomic uncertainty caused the Company to perform an interim goodwill impairment test as of March 31, 2020 over the Insulation reporting unit. After evaluating and weighing all relevant events and circumstances, and considering the substantial excess fair values for the Roofing and Composites reporting units, we concluded that it was not more likely than not that the fair values of these reporting units were less than their carrying values. Consequently, we determined that it was not necessary to perform an interim impairment test for the Roofing and Composites reporting units. Based on the results of this interim testing over the Insulation reporting unit, the Company recorded a $944 million pre-tax non-cash impairment charge in the first quarter of 2020. This charge was recorded in Goodwill impairment charge on the Consolidated Statements of Earnings (Loss), and was included in the Corporate, Other and Eliminations reporting category. Consistent with the Company’s adoption of ASU 2017-04 in the first quarter of 2020, the impairment charge was equal to the excess of the Insulation reporting unit’s carrying value over its fair value. The overall enterprise fair value of the Company was limited by the decline in our share price in the first quarter of 2020. The reduction in fair value for the Insulation reporting unit, and corresponding impairment charge, was primarily driven by an increase in the discount rate arising from higher equity risk premiums that reflect significant uncertainty surrounding the effect from the COVID-19 pandemic and a decrease in the reporting unit's forecasted near-term cash flows. As part of our quantitative testing process for goodwill of the Insulation reporting unit, we estimated fair values using a discounted cash flow analysis, a form of the income approach, from the perspective of a market participant. Significant assumptions used in the discounted cash flow approach are revenue growth rates and EBIT margins used in estimating discrete period cash flow forecasts of the reporting unit, the discount rate, and the long-term revenue growth rate and EBIT margins used in estimating the terminal business value. The terminal business value is determined by applying the long-term growth rate to the latest year for which a forecast exists. Annual 2020 Goodwill Impairment Assessment The annual tests performed in the fourth quarter of 2020 resulted in no impairment of goodwill. The changes in the net carrying amount of goodwill by segment are as follows (in millions): Composites Insulation Roofing Total Balance at December 31, 2019 $ 57 $ 1,479 $ 396 $ 1,932 Impairment charge — (944) — (944) Divestiture — (4) — (4) Foreign currency translation — 1 4 5 Balance at December 31, 2020 $ 57 $ 532 $ 400 $ 989 Other Intangible Assets The Company amortizes the cost of other intangible assets over their estimated useful lives which, individually, range up to 45 years. The Company's future cash flows are not materially impacted by its ability to extend or renew agreements related to its amortizable intangible assets. First Quarter of 2020 Indefinite-lived Intangibles Impairment Charge In the first quarter of 2020, we performed an interim impairment test of one indefinite-lived trademark and one trade name used by our Insulation segment, based on the macroeconomic conditions that precipitated the interim goodwill impairment test described above. Based on the results of this testing, the Company recorded pre-tax non-cash impairment charges totaling $43 million in the first quarter of 2020 related to one trademark and one trade name in the Insulation segment. These charges were recorded in Other expenses, net on the Consolidated Statements of Earnings (Loss), and were included in the Corporate, Other and Eliminations reporting category. Fair values used in testing for potential impairment of our trademarks are calculated using the relief-from-royalty method by applying an estimated market value royalty rate to the forecasted revenues of the businesses that utilize those assets. The assumed cash flows from this calculation are discounted at a rate based on a market participant discount rate. A pre-tax impairment charge of $34 million for a trade name used by our European building and technical insulation business was recognized in the first quarter of 2020 due to the combined effect of lower expected sales following an immaterial divestiture in the first quarter of 2020, a decrease in the forecasted near-term cash flows, and a higher discount rate associated with the economic impact and uncertainty from the COVID-19 pandemic. A pre-tax impairment charge of $9 million related to a trademark used on global cellular glass insulation products was recorded in the first quarter of 2020 due to a slightly lower sales outlook and a similarly higher discount rate associated with the economic impact and uncertainty from the COVID-19 pandemic. The assets affected by the impairment charge had an aggregate carrying value of $264 million as of December 31, 2020. Annual 2020 Indefinite-lived Intangibles Impairment Assessment The annual tests performed in 2020 resulted in no impairment of indefinite-lived intangible assets. Testing did indicate that the fair value of a trade name used by our European building and technical insulation business within our Insulation segment exceeded its carrying value by approximately 7%. A change in the estimated long-term revenue growth rate or increase in the discount rate assumption could increase the likelihood of a future impairment for this asset. The affected asset had a carrying value of $173 million as of December 31, 2020. The Other category below primarily includes emissions and quarry rights. Other intangible assets consist of the following (in millions): December 31, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Accumulated Net Trademarks and trade names $ 1,109 $ — $ 1,109 $ 1,139 $ — $ 1,139 Customer relationships 570 (200) 370 550 (167) 383 Technology 327 (172) 155 319 (152) 167 Other 36 (3) 33 67 (35) 32 Total other intangible assets $ 2,042 $ (375) $ 1,667 $ 2,075 $ (354) $ 1,721 Amortization expense for intangible assets for the years ended December 31, 2020, 2019, and 2018 was $48 million, $49 million, and $49 million, respectively. The estimated amortization expense for intangible assets for the next five years is as follows (in millions): Period Amortization 2021 $ 49 2022 $ 47 2023 $ 43 2024 $ 40 2025 $ 40

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment consist of the following (in millions): December 31, 2020 2019 Land $ 222 $ 221 Buildings and leasehold improvements 1,241 1,186 Machinery and equipment 5,155 4,978 Construction in progress 292 310 6,910 6,695 Accumulated depreciation (3,101) (2,840) Property, plant and equipment, net $ 3,809 $ 3,855 Machinery and equipment includes certain precious metals used in our production tooling, which comprise approximately 10% of total machinery and equipment as of both December 31, 2020 and December 31, 2019. For the years ended December 31, 2020, 2019 and 2018, depreciation expense was $429 million, $403 million and $384 million, respectively, which includes depletion expense related to precious metals used in our production tooling. In 2020, 2019 and 2018, depreciation expense included $20 million, $9 million and $10 million, respectively, of accelerated depreciation related to restructuring actions further explained in Note 10 to the Consolidated Financial Statements.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
LEASES	The Company leases certain equipment and facilities under both operating and finance leases expiring on various dates through 2036. The nature of these leases generally fall into the following five categories: real estate, material handling, fleet vehicles, office equipment and energy equipment. For leases with initial terms greater than 12 months, we consider these our right-of-use assets and record the related asset and obligation at the present value of lease payments over the term. For leases with initial terms equal to or less than 12 months, we do not consider them as right-of-use assets and instead consider them short-term lease costs that are recognized on a straight-line basis over the lease term. Many of our leases include escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments when reasonably certain. These options to extend or terminate a lease are at our discretion. We have elected to take the practical expedient and not separate lease and non-lease components of contracts. We estimate our incremental borrowing rate to discount the lease payments based on information available at lease commencement. Our lease agreements do not contain any material residual value guarantees. Balance Sheet Classification The table below presents the lease-related assets and liabilities recorded on the balance sheet (in millions): December 31, Leases Classification on Balance Sheet 2020 2019 Assets Operating lease assets Operating lease right-of-use assets $ 154 $ 203 Finance lease assets Other non-current assets 73 21 Total lease assets $ 227 $ 224 Liabilities Current Operating Total current liabilities $ 55 $ 66 Finance Total current liabilities 19 7 Non-Current Operating Non-current operating lease liabilities 99 138 Finance Long-term debt, net of current portion 59 19 Total lease liabilities $ 232 $ 230 Lease Costs The table below presents lease-related costs (in millions): Twelve Months Ended December 31, 2020 2019 Operating lease cost $ 71 $ 81 Finance lease cost Amortization $ 16 $ 5 Interest $ 3 $ 2 Short-term lease cost $ 11 $ 10 Variable lease cost $ 5 $ 6 For the year ended December 31, 2018, total rent expense accounted for under ASC 840 was $106 million. Cash paid for operating leases approximated operating lease expense for both years ended December 31, 2020 and 2019. Cash paid for finance leases included $16 million for financing activities and $3 million for operating activities for the year ended December 31, 2020. Cash paid for finance leases included $5 million for financing activities and $2 million for operating activities for the year ended December 31, 2019. We added $36 million and $47 million of operating lease liabilities as a result of obtaining operating lease right-of-use assets in the years ended December 31, 2020 and 2019, respectively. We added $69 million and $12 million of finance lease liabilities as a result of obtaining finance lease right-of-use assets in the years ended December 31, 2020 and 2019, respectively. Other Information The tables below present supplemental information related to leases: December 31, Weighted-average remaining lease term (years) 2020 2019 Operating leases 3.8 4.0 Finance leases 6.8 3.9 December 31, Weighted-average discount rate 2020 2019 Operating leases 3.29 % 3.30 % Finance leases 4.04 % 6.29 % Maturities of Lease Liabilities The table below reconciles the undiscounted cash flows for each of the first five years and the total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheet as of December 31, 2020 (in millions): Period Operating Leases Finance Leases 2021 $ 59 $ 22 2022 45 19 2023 28 14 2024 15 8 2025 8 5 2026 and beyond 13 21 Total minimum lease payments 168 89 Less: implied interest 14 11 Present value of future minimum lease payments 154 78 Less: current lease obligations 55 19 Long-term lease obligations $ 99 $ 59
LEASES	The Company leases certain equipment and facilities under both operating and finance leases expiring on various dates through 2036. The nature of these leases generally fall into the following five categories: real estate, material handling, fleet vehicles, office equipment and energy equipment. For leases with initial terms greater than 12 months, we consider these our right-of-use assets and record the related asset and obligation at the present value of lease payments over the term. For leases with initial terms equal to or less than 12 months, we do not consider them as right-of-use assets and instead consider them short-term lease costs that are recognized on a straight-line basis over the lease term. Many of our leases include escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments when reasonably certain. These options to extend or terminate a lease are at our discretion. We have elected to take the practical expedient and not separate lease and non-lease components of contracts. We estimate our incremental borrowing rate to discount the lease payments based on information available at lease commencement. Our lease agreements do not contain any material residual value guarantees. Balance Sheet Classification The table below presents the lease-related assets and liabilities recorded on the balance sheet (in millions): December 31, Leases Classification on Balance Sheet 2020 2019 Assets Operating lease assets Operating lease right-of-use assets $ 154 $ 203 Finance lease assets Other non-current assets 73 21 Total lease assets $ 227 $ 224 Liabilities Current Operating Total current liabilities $ 55 $ 66 Finance Total current liabilities 19 7 Non-Current Operating Non-current operating lease liabilities 99 138 Finance Long-term debt, net of current portion 59 19 Total lease liabilities $ 232 $ 230 Lease Costs The table below presents lease-related costs (in millions): Twelve Months Ended December 31, 2020 2019 Operating lease cost $ 71 $ 81 Finance lease cost Amortization $ 16 $ 5 Interest $ 3 $ 2 Short-term lease cost $ 11 $ 10 Variable lease cost $ 5 $ 6 For the year ended December 31, 2018, total rent expense accounted for under ASC 840 was $106 million. Cash paid for operating leases approximated operating lease expense for both years ended December 31, 2020 and 2019. Cash paid for finance leases included $16 million for financing activities and $3 million for operating activities for the year ended December 31, 2020. Cash paid for finance leases included $5 million for financing activities and $2 million for operating activities for the year ended December 31, 2019. We added $36 million and $47 million of operating lease liabilities as a result of obtaining operating lease right-of-use assets in the years ended December 31, 2020 and 2019, respectively. We added $69 million and $12 million of finance lease liabilities as a result of obtaining finance lease right-of-use assets in the years ended December 31, 2020 and 2019, respectively. Other Information The tables below present supplemental information related to leases: December 31, Weighted-average remaining lease term (years) 2020 2019 Operating leases 3.8 4.0 Finance leases 6.8 3.9 December 31, Weighted-average discount rate 2020 2019 Operating leases 3.29 % 3.30 % Finance leases 4.04 % 6.29 % Maturities of Lease Liabilities The table below reconciles the undiscounted cash flows for each of the first five years and the total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheet as of December 31, 2020 (in millions): Period Operating Leases Finance Leases 2021 $ 59 $ 22 2022 45 19 2023 28 14 2024 15 8 2025 8 5 2026 and beyond 13 21 Total minimum lease payments 168 89 Less: implied interest 14 11 Present value of future minimum lease payments 154 78 Less: current lease obligations 55 19 Long-term lease obligations $ 99 $ 59

TOTAL CURRENT LIABILITIES

TOTAL CURRENT LIABILITIES	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
TOTAL CURRENT LIABILITIES	TOTAL CURRENT LIABILITIES Current liabilities consist of the following current portions of these liabilities (in millions): December 31, 2020 2019 Accounts payable $ 875 $ 815 Payroll, vacation pay and incentive compensation 197 172 Current operating lease liabilities 55 66 Other 313 276 Total $ 1,440 $ 1,329

WARRANTIES

WARRANTIES	12 Months Ended
	Dec. 31, 2020
Product Warranties Disclosures [Abstract]
WARRANTIES	The Company records a liability for warranty obligations at the date the related products are sold. Adjustments are made as new information becomes available. Please refer to Note 1 for information about our separately-priced extended warranty contracts. A reconciliation of the warranty liability is as follows (in millions): December 31, 2020 2019 Beginning balance $ 64 $ 60 Amounts accrued for current year 21 21 Settlements of warranty claims (13) (17) Ending balance $ 72 $ 64

RESTRUCTURING AND ACQUISITION-R

RESTRUCTURING AND ACQUISITION-RELATED COSTS	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND ACQUISITION-RELATED COSTS	RESTRUCTURING AND ACQUISITION-RELATED COSTS The Company may incur restructuring, transaction and integration costs related to acquisitions, and may incur restructuring costs in connection with its global cost reduction and productivity initiatives. 2020 Insulation Restructuring Actions During the fourth quarter of 2020, the Company took actions to avoid future capital outlays and reduce costs in its global Insulation segment, mainly through decisions to close certain manufacturing facilities in Shanghai, China and Fresno, Texas, and optimize a facility in Parainen, Finland. During 2020, the Company recorded $23 million of charges, inclusive of $14 million of accelerated depreciation, $6 million of severance and $3 million of other exit costs. The Company expects to recognize approximately $5 million of incremental charges throughout 2021 related to these actions. 2020 Composites Restructuring Actions During 2020, the Company took actions to reduce costs throughout its global Composites segment primarily through global workforce reductions, closure of manufacturing lines and other asset write-offs. As a result of these actions, the Company recorded $13 million of charges during 2020, inclusive of $6 million of severance, $5 million of accelerated depreciation and $2 million of other exit costs. The Company does not expect to recognize significant incremental costs related to these actions. Insulation Network Optimization Restructuring In October 2019, the Company took actions to primarily restructure certain U.S. insulation operations and to reduce the cost structure throughout the Insulation network. Investments in productivity and process technologies enabled the Company to optimize its network and improve its cost position. During 2020, the Company recorded $5 million of charges. The Company does not expect to recognize significant incremental costs related to these actions. Acquisition-Related Restructuring Following the acquisitions of Paroc Group Oy ("Paroc") and Pittsburgh Corning Corporation and Pittsburgh Corning Europe NV (collectively, "Pittsburgh Corning") into the Company's Insulation segment, the Company took actions to realize expected synergies from the newly acquired operations. The Company does not expect to recognize significant incremental costs related to these actions. Consolidated Statements of Earnings (Loss) Classification The following table presents the impact and respective location of total restructuring costs on the Consolidated Statements of Earnings (Loss), which are included in our Corporate, Other and Eliminations category (in millions): Twelve Months Ended December 31, Type of Cost Location 2020 2019 2018 Accelerated depreciation Cost of sales $ 20 $ 9 $ 10 Other exit costs Cost of sales 6 6 7 Severance Other expenses, net 13 13 4 Other exit costs/(gains) (a) Other expenses, net 2 (1) 1 Other exit costs Non-operating expense (income) — 1 — Total restructuring costs $ 41 $ 28 $ 22 (a) Other exit costs/(gains) in 2019 includes a $6 million gain related to the sale of an idle residential fiberglass insulation facility in Canada resulting from restructuring actions taken in 2016. Summary of Unpaid Liabilities The following table summarizes the status of the unpaid liabilities from the Company’s restructuring activities (in millions): 2020 Insulation Restructuring Actions 2020 Composites Restructuring Actions Insulation Network Optimization Restructuring Acquisition-Related Restructuring Balance at December 31, 2019 $ — $ — $ 5 $ 11 Restructuring costs 23 13 5 — Payments (4) (6) (8) (6) Accelerated depreciation and other non-cash items (17) (5) (2) 4 Balance at December 31, 2020 $ 2 $ 2 $ — $ 9 Cumulative charges incurred $ 23 $ 13 $ 29 $ 29 As of December 31, 2020, the remaining liability balance is comprised of $13 million of severance, inclusive of $3 million of non-current severance and $10 million of severance the Company expects to pay over the next twelve months.

DEBT

DEBT	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
DEBT	Details of the Company’s outstanding long-term debt, as well as the fair values, are as follows (in millions): December 31, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value 4.200% senior notes, net of discount and financing fees, due 2022 $ 184 106 % $ 183 104 % 4.200% senior notes, net of discount and financing fees, due 2024 396 111 % 395 106 % 3.400% senior notes, net of discount and financing fees, due 2026 397 111 % 396 101 % 3.950% senior notes, net of discount and financing fees, due 2029 445 115 % 445 104 % 3.875% senior notes, net of discount and financing fees, due 2030 297 115 % — — % 7.000% senior notes, net of discount and financing fees, due 2036 368 142 % 367 126 % 4.300% senior notes, net of discount and financing fees, due 2047 588 120 % 588 95 % 4.400% senior notes, net of discount and financing fees, due 2048 390 121 % 390 97 % Various finance leases, due through 2036 (a) 78 100 % 26 100 % Term loan borrowing, maturing in 2021 (a) — — % 200 100 % Other 2 n/a 3 n/a Total long-term debt 3,145 n/a 2,993 n/a Less – current portion (a) 19 100 % 7 100 % Long-term debt, net of current portion $ 3,126 n/a $ 2,986 n/a (a) The Company determined that the book value of the above noted long-term debt instruments approximates fair value. The fair values of the Company's outstanding long-term debt instruments were estimated using market observable inputs, including quoted prices in active markets, market indices and interest rate measurements. Within the hierarchy of fair value measurements, these are Level 2 fair values. Senior Notes The Company issued $300 million of 2030 senior notes on May 12, 2020 subject to $3 million of discounts and issuance costs. Interest on the notes is payable semiannually in arrears on June 1 and December 1 each year, beginning on December 1, 2020. The proceeds from these notes were used for general corporate purposes. The Company issued $450 million of 2029 senior notes on August 12, 2019 subject to $5 million of discounts and issuance costs. Interest on the notes is payable semiannually in arrears on February 15 and August 15 each year, beginning on February 15, 2020. The proceeds from these notes were used to repay $416 million of our 2022 senior notes and $34 million of our 2036 senior notes. The Company issued $400 million of 2048 senior notes on January 25, 2018. Interest on the notes is payable semiannually in arrears on January 30 and July 30 each year, beginning on July 30, 2018. The proceeds from these notes were used, along with borrowings on a $600 million term loan commitment and borrowings on the Receivables Securitization Facility (as defined below), to fund the purchase of Paroc in the first quarter of 2018. The Company issued $600 million of 2047 senior notes on June 26, 2017. Interest on the notes is payable semiannually in arrears on January 15 and July 15 each year, beginning on January 15, 2018. A portion of the proceeds from these notes was used to fund the purchase of Pittsburgh Corning in 2017 and for general corporate purposes. The remaining proceeds were used to repay $144 million of our 2019 senior notes and $140 million of our 2036 senior notes. The Company issued $400 million of 2026 senior notes on August 8, 2016. Interest on the notes is payable semiannually in arrears on February 15 and August 15 each year, beginning on February 15, 2017. A portion of the proceeds from these notes was used to redeem $158 million of our 2016 senior notes. The remaining proceeds were used to pay down portions of our Receivables Securitization Facility and for general corporate purposes. The Company issued $400 million of 2024 senior notes on November 12, 2014. Interest on the notes is payable semiannually in arrears on June 1 and December 1 each year, beginning on June 1, 2015. A portion of the proceeds from these notes was used to repay $242 million of our 2016 senior notes and $105 million of our 2019 senior notes. The remaining proceeds were used to pay down our Senior Revolving Credit Facility (as defined below), finance general working capital needs, and for general corporate purposes. The Company issued $600 million of 2022 senior notes on October 17, 2012. Interest on the notes is payable semiannually in arrears on June 15 and December 15 each year, beginning on June 15, 2013. The proceeds of these notes were used to refinance $250 million of our 2016 senior notes and $100 million of our 2019 senior notes and pay down our Senior Revolving Credit Facility. On October 31, 2006, the Company issued $550 million of 2036 senior notes. The proceeds of these notes were used to pay certain unsecured and administrative claims, finance general working capital needs and for general corporate purposes. Collectively, the notes above are referred to as the “Senior Notes.” The Senior Notes are general unsecured obligations of the Company and rank pari passu with all existing and future senior unsecured indebtedness of the Company. In May 2018, the Company entered into a new agreement covering our Senior Revolving Credit Facility. This new agreement, among other things, removed all subsidiaries of the Company as guarantors under our Senior Revolving Credit Facility, unless certain conditions precedent are met that do not exist at this time, and had the effect of removing the guarantees of such subsidiaries under our Senior Notes. In addition, we elected to amend our Registration Statement on Form S-3 to eliminate the guarantees of our Senior Notes as registered securities. The Company has the option to redeem all or part of the Senior Notes at any time at a “make-whole” redemption price. The Company is subject to certain covenants in connection with the issuance of the Senior Notes that it believes are usual and customary. The Company was in compliance with these covenants as of December 31, 2020. Senior Revolving Credit Facility The Company has an $800 million senior revolving credit facility (the "Senior Revolving Credit Facility") with a maturity date in May 2024 that includes both borrowings and letters of credit. Borrowings under the Senior Revolving Credit Facility may be used for general corporate purposes and working capital. The Company has the discretion to borrow under multiple options, which provide for varying terms and interest rates including the United States prime rate, federal funds rate plus a spread or LIBOR plus a spread. The Senior Revolving Credit Facility contains various covenants, including a maximum allowed leverage ratio and a minimum required interest expense coverage ratio, that the Company believes are usual and customary for a senior unsecured credit agreement. The Company was in compliance with these covenants as of December 31, 2020. Please refer to the Credit Facility Utilization paragraph below for liquidity information as of December 31, 2020. Term Loan Borrowing The Company obtained a term loan commitment on October 27, 2017 for $600 million (the "Term Loan"). The Company entered into the Term Loan, in part, to pay a portion of the purchase price of the Paroc acquisition. In the first quarter of 2018, the Company borrowed on the Term Loan, along with borrowings on the Receivables Securitization Facility and the proceeds of the 2048 senior notes, to fund the purchase of Paroc. The Term Loan agreement contained partial quarterly principal repayments and full repayment by February 2021. The Term Loan contains various covenants, including a maximum allowed leverage ratio and a minimum required interest expense coverage ratio, that the Company believes are usual and customary for a term loan. In the third quarter of 2020, the Company repaid all outstanding borrowings on the Term Loan. Receivables Securitization Facility Included in long-term debt on the Consolidated Balance Sheets are borrowings outstanding under a Receivables Purchase Agreement ("RPA") that are accounted for as secured borrowings in accordance with ASC 860, "Accounting for Transfers and Servicing." Owens Corning Sales, LLC and Owens Corning Receivables LLC, each a subsidiary of the Company, have a $280 million RPA with certain financial institutions. The Company has the ability to borrow at the lenders' cost of funds, which approximates A-1/P-1 commercial paper rates vs. LIBOR, plus a fixed spread. In April 2019, the securitization facility (the "Receivables Securitization Facility") was amended to extend the maturity date to April 2022. The Receivables Securitization Facility contains various covenants, including a maximum allowed leverage ratio and a minimum required interest expense coverage ratio that the Company believes are usual and customary for a securitization facility. The Company was in compliance with these covenants as of December 31, 2020. Please refer to the Credit Facility Utilization section below for liquidity information as of December 31, 2020. Owens Corning Receivables LLC’s sole business consists of the purchase or acceptance through capital contributions of trade receivables and related rights from Owens Corning Sales, LLC and the subsequent retransfer of or granting of a security interest in such trade receivables and related rights to certain purchasers who are party to the RPA. Owens Corning Receivables LLC is a separate legal entity with its own separate creditors who will be entitled, upon its liquidation, to be satisfied out of Owens Corning Receivables LLC’s assets prior to any assets or value in Owens Corning Receivables LLC becoming available to Owens Corning Receivables LLC’s equity holders. The assets of Owens Corning Receivables LLC are not available to pay creditors of the Company or any other affiliates of the Company or Owens Corning Sales, LLC. Credit Facility Utilization The following table shows how the Company utilized its primary sources of liquidity (in millions): Balance at December 31, 2020 Senior Revolving Credit Facility Receivables Securitization Facility Facility size $ 800 $ 280 Collateral capacity limitation on availability n/a — Outstanding borrowings — — Outstanding letters of credit 4 1 Availability on facility $ 796 $ 279 Debt Maturities The aggregate maturities for all outstanding long-term debt borrowings for each of the five years following December 31, 2020 and thereafter are presented in the table below (in millions). The maturities below are the aggregate par amounts of the outstanding senior notes and finance lease liabilities: Period Maturities 2021 $ 19 2022 201 2023 13 2024 407 2025 4 2026 and beyond 2,544 Total $ 3,188 Short-Term Debt At December 31, 2020 and December 31, 2019, short-term borrowings were $1 million and $20 million, respectively. The short-term borrowings for both periods consisted of various operating lines of credit and working capital facilities. Certain of these borrowings are collateralized by receivables, inventories or property. The borrowing facilities are typically for one

PENSION PLANS

PENSION PLANS	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
PENSION PLANS	Pension Plans The Company sponsors defined benefit pension plans. Under the plans, pension benefits are based on an employee’s years of service and, for certain categories of employees, qualifying compensation. Company contributions to these pension plans are determined by an independent actuary to meet or exceed minimum funding requirements. In our U.S. plan, the unrecognized cost of any retroactive amendments and actuarial gains and losses are amortized over the average remaining life expectancy of inactive participants. In all of our Non-U.S plans, the unrecognized cost of any retroactive amendments and actuarial gains and losses are amortized over the average future service period of plan participants expected to receive benefits. During 2019, the Company completed balance sheet risk mitigation actions related to certain U.S. and non-U.S. pension plans. These actions included the purchase of non-participating annuity contracts from insurance companies and the payment of lump sums to retirees, which resulted in the settlement of liabilities to affected participants. As a result of these transactions, the Company recognized pension settlement losses of $43 million during the twelve months ended December 31, 2019. These losses are included in Non-operating expense (income) on the Consolidated Statements of Earnings (Loss) in our Corporate, Other and Eliminations category. These transactions did not have a material effect on the plans' funded status. The following tables provide a reconciliation of the change in the projected benefit obligation, the change in plan assets and the net amount recognized in the Consolidated Balance Sheets (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 866 $ 475 $ 1,341 $ 891 $ 427 $ 1,318 Service cost 5 5 10 5 5 10 Interest cost 28 10 38 34 13 47 Actuarial loss 83 28 111 85 42 127 Currency loss — 18 18 — 13 13 Benefits paid (71) (16) (87) (45) (18) (63) Plan amendments — 3 3 — — — Settlements/curtailments (1) (4) (5) (104) (7) (111) Other — 4 4 — — — Benefit obligation at end of period $ 910 $ 523 $ 1,433 $ 866 $ 475 $ 1,341 December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Plan Assets Fair value of assets at beginning of period $ 733 $ 386 $ 1,119 $ 727 $ 328 $ 1,055 Actual return on plan assets 80 37 117 130 50 180 Currency gain — 14 14 — 11 11 Company contributions 101 21 122 25 21 46 Benefits paid (71) (16) (87) (45) (18) (63) Settlements/curtailments (1) (4) (5) (104) (5) (109) Other — 3 3 — (1) (1) Fair value of assets at end of period $ 842 $ 441 $ 1,283 $ 733 $ 386 $ 1,119 Funded status $ (68) $ (82) $ (150) $ (133) $ (89) $ (222) December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 12 $ 12 $ — $ 11 $ 11 Accrued pension cost – current — (2) (2) — (2) (2) Accrued pension cost – non-current (68) (92) (160) (133) (98) (231) Net amount recognized $ (68) $ (82) $ (150) $ (133) $ (89) $ (222) Amounts Recorded in AOCI Net actuarial loss $ (381) $ (109) $ (490) $ (345) $ (97) $ (442) For the year ended December 31, 2020, the actuarial loss of $111 million was largely the result of decreases in discount rates across all plans. In the U.S. plan, the actuarial loss was primarily driven by the decrease in the discount rate. Additionally, updated mortality assumptions and a decrease in the cash balance interest crediting rate negatively impacted the projected benefit obligation (PBO). In the Non-U.S. plans, the actuarial loss was driven by a decrease in the discount rate of the U.K. and other plans, partially offset by inflation. For the year ended December 31, 2019, the actuarial loss of $127 million was largely the result of decreases in discount rates across all plans. In the U.S. plans, the actuarial loss was primarily driven by a decrease in the discount rate. In the Non-U.S. plans, the actuarial loss was driven by a decrease in the discount rate of the U.K. and other plans, partially offset by inflation. The following table presents information about the projected benefit obligation, accumulated benefit obligation (ABO) and plan assets of the Company’s pension plans (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with PBO in excess of fair value of plan assets: Projected benefit obligation $ 910 $ 364 $ 1,274 $ 866 $ 329 $ 1,195 Fair value of plan assets $ 842 $ 270 $ 1,112 $ 733 $ 229 $ 962 Plans with ABO in excess of fair value of plan assets: Accumulated benefit obligation $ 910 $ 330 $ 1,240 $ 866 $ 295 $ 1,161 Fair value of plan assets $ 842 $ 249 $ 1,091 $ 733 $ 205 $ 938 Weighted-Average Assumptions Used to Determine Benefit Obligation The following table presents weighted average assumptions used to determine benefit obligations at the measurement dates: December 31, 2020 2019 United States Plans Discount rate 2.50 % 3.30 % Expected return on plan assets 4.75 % 6.50 % Cash balance interest crediting rate 0.79 % 2.66 % Non-United States Plans Discount rate 1.73 % 2.24 % Expected return on plan assets 4.08 % 4.66 % Rate of compensation increase 3.00 % 3.99 % Components of Net Periodic Pension Cost (Income) The following table presents the components of net periodic pension cost (income) (in millions): Twelve Months Ended December 31, 2020 2019 2018 Service cost $ 10 $ 10 $ 12 Interest cost 38 47 47 Expected return on plan assets (62) (68) (73) Amortization of actuarial loss 15 15 15 Settlement/curtailment 1 44 — Net periodic pension cost $ 2 $ 48 $ 1 Weighted-Average Assumptions Used to Determine Net Periodic Pension Cost The following table presents weighted-average assumptions used to determine net periodic pension costs for the periods noted: Twelve Months Ended December 31, 2020 2019 2018 United States Plans Discount rate 3.30 % 4.25 % 3.55 % Expected return on plan assets 6.50 % 6.75 % 6.75 % Cash balance interest crediting rate 2.66 % 3.77 % 3.10 % Rate of compensation increase N/A (a) N/A (a) N/A (a) Non-United States Plans Discount rate 2.24 % 3.04 % 2.88 % Expected return on plan assets 4.66 % 4.91 % 5.22 % Rate of compensation increase 3.99 % 4.14 % 4.29 % (a) Not applicable due to changes in plan made on August 1, 2009 that were effective beginning January 1, 2010. The expected return on plan assets assumption is derived by taking into consideration the target plan asset allocation, historical rates of return on those assets, projected future asset class returns and net outperformance of the market by active investment managers. An asset return model is used to develop an expected range of returns on plan investments over a 20 year period, with the expected rate of return selected from a best estimate range within the total range of projected results. The result is then rounded down to the nearest 25 basis points. Items Measured at Fair Value The Company classifies and discloses pension plan assets in one of the following three categories: Level 1: Quoted market prices in active markets for identical assets. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. Plan Assets The tables in this section show pension plan asset fair values and fair value leveling information. The assets are categorized into one of the three levels of the fair value hierarchy or are not subject to leveling, in the case of investments that are valued using the net asset value per share (or its equivalent) practical expedient ("NAV"). The following table summarizes the fair values and applicable fair value hierarchy levels of United States pension plan assets (in millions): December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 53 $ — $ — $ 53 Fixed income and cash equivalents: Corporate bonds 31 288 — 319 Government debt — 68 — 68 Total United States plan assets subject to leveling $ 84 $ 356 $ — 440 Plan assets measured at NAV: Equities 193 Fixed income and cash equivalents 157 Absolute return strategies 52 Total United States plan assets $ 842 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 57 $ — $ — $ 57 International 55 — — 55 Fixed income and cash equivalents: Corporate bonds 28 214 — 242 Government debt — 85 — 85 Real estate investment trusts 22 — — 22 Total United States plan assets subject to leveling $ 162 $ 299 $ — 461 Plan assets measured at NAV: Equities 130 Real assets 62 Fixed income and cash equivalents 33 Absolute return strategies 47 Total United States plan assets $ 733 The following table summarizes the fair values and applicable fair value hierarchy levels of non-United States pension plan assets (in millions): December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 2 $ — $ 2 Cash and cash equivalents — 81 — 81 Fixed income — 9 — 9 Total non-United States plan assets subject to leveling $ — $ 92 $ — 92 Plan assets measured at NAV: Equities 86 Fixed income and cash equivalents 156 Absolute return strategies and other 107 Total non-United States plan assets $ 441 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents: Cash and cash equivalents — 65 — 65 Corporate bonds — 13 — 13 Total non-United States plan assets subject to leveling $ — $ 82 $ — 82 Plan assets measured at NAV: Equities 71 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 386 Investment Strategy The current targeted asset allocation for the United States pension plan is to have 28.5% of assets invested in equities, 65.5% in intermediate and long-term fixed income securities and 6% in absolute return strategies. Assets are rebalanced quarterly to conform to policy tolerances. The Company actively evaluates the reasonableness of its asset mix given changes in the projected benefit obligation and market dynamics. Our investment policy and asset mix for the non-United States pension plans varies by location and is based on projected benefit obligation and market dynamics. Estimated Future Benefit Payments The following table shows estimated future benefit payments from the Company’s pension plans (in millions): Year Estimated Benefit Payments 2021 $ 82 2022 $ 78 2023 $ 78 2024 $ 79 2025 $ 76 2026-2030 $ 376 Contributions The Company does not expect to contribute to the U.S. pension plan during 2021. The Company expects to contribute $25 million in cash to non-U.S. plans during 2021. Actual contributions to the plans may change as a result of a variety of factors, including changes in laws that impact funding requirements. Defined Contribution Plans The Company sponsors two defined contribution plans which are available to substantially all United States employees. The Company matches a percentage of employee contributions up to a maximum level and contributes up to 2% of an employee’s wages regardless of employee contributions. The Company recognized expense of $48 million during the years ended December 31, 2020, 2019 and 2018, related to these plans. The Company maintains health care and life insurance benefit plans for certain retired employees and their dependents. The health care plans in the United States are non-funded and pay either (1) stated percentages of covered medically necessary expenses, after subtracting payments by Medicare or other providers and after stated deductibles have been met, or (2) fixed amounts of medical expense reimbursement. Salaried employees hired on or before December 31, 2005 become eligible to participate in the United States health care plans upon retirement if they have accumulated 10 years of service after age 45, 48 or 50, depending on the category of employee. For employees hired after December 31, 2005, the Company does not provide subsidized retiree health care. Some of the plans are contributory, with some retiree contributions adjusted annually. The Company has reserved the right to change or eliminate these benefit plans subject to the terms of collective bargaining agreements. The following table provides a reconciliation of the change in the projected benefit obligation and the net amount recognized in the Consolidated Balance Sheets for the years ended December 31, 2020 and 2019 (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 169 $ 14 $ 183 $ 183 $ 12 $ 195 Service cost 1 — 1 1 — 1 Interest cost 5 1 6 7 1 8 Actuarial loss/(gain) — 1 1 (7) 2 (5) Currency gain — (1) (1) — — — Plan amendments — — — (1) — (1) Benefits paid (12) (1) (13) (14) (1) (15) Benefit obligation at end of period $ 163 $ 14 $ 177 $ 169 $ 14 $ 183 Funded status $ (163) $ (14) $ (177) $ (169) $ (14) $ (183) Amounts Recognized in the Consolidated Balance Sheets Accrued benefit obligation – current $ (13) $ (1) $ (14) $ (15) $ (1) $ (16) Accrued benefit obligation – non-current (150) (13) (163) (154) (13) $ (167) Net amount recognized $ (163) $ (14) $ (177) $ (169) $ (14) $ (183) Amounts Recorded in AOCI Net actuarial gain $ 41 $ 2 $ 43 $ 48 $ 3 $ 51 Net prior service credit 2 — 2 6 — 6 Net amount recognized $ 43 $ 2 $ 45 $ 54 $ 3 $ 57 The following table presents information about the accumulated postretirement benefit obligation (APBO) and plan assets of the Company's postretirement benefit plans (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with APBO in excess of fair value of plan assets: Accumulated postretirement benefit obligation $ 163 $ 14 $ 177 $ 169 $ 14 $ 183 Fair value of plan assets $ — $ — $ — $ — $ — $ — Weighted-Average Assumptions Used to Determine Benefit Obligations The following table presents the discount rates used to determine the benefit obligations: December 31, 2020 2019 United States plans 2.25 % 3.10 % Non-United States plans 3.04 % 3.84 % Components of Net Periodic Postretirement Benefit Cost (Income) The following table presents the components of net periodic postretirement benefit cost (income) (in millions): Twelve Months Ended December 31, 2020 2019 2018 Service cost $ 1 $ 1 $ 1 Interest cost 6 8 8 Amortization of prior service credit (4) (4) (4) Amortization of actuarial gain (8) (8) (6) Net periodic postretirement benefit income $ (5) $ (3) $ (1) Weighted-Average Assumptions Used to Determine Net Periodic Postretirement Benefit Cost The following table presents the discount rates used to determine net periodic postretirement benefit cost: Twelve Months Ended December 31, 2020 2019 2018 United States plans 3.10 % 4.15 % 3.45 % Non-United States plans 3.84 % 4.59 % 4.56 % The following table presents health care cost trend rates used to determine net periodic postretirement benefit cost, as well as information regarding the ultimate rate and the year in which the ultimate rate is reached: Twelve Months Ended December 31, 2020 2019 2018 United States plans: Initial rate at end of year 8.20 % 6.50 % 6.75 % Ultimate rate 4.50 % 5.00 % 5.00 % Year in which ultimate rate is reached 2029 2026 2026 Non-United States plans: Initial rate at end of year 4.10 % 5.45 % 5.40 % Ultimate rate 3.90 % 5.45 % 5.40 % Year in which ultimate rate is reached 2040 2019 2019 Estimated Future Benefit Payments The following table shows estimated future benefit payments from the Company’s postretirement benefit plans (in millions): Year Estimated Benefit Payments 2021 $ 14 2022 $ 14 2023 $ 13 2024 $ 13 2025 $ 12 2026-2030 $ 55 Postemployment Benefits The Company may also provide benefits to former or inactive employees after employment but before retirement under certain conditions. These benefits include continuation of benefits such as health care and life insurance coverage. The accrued postemployment benefits liability at December 31, 2020 and 2019 was $8 million and $11 million, respectively. The net periodic postemployment benefit (income)/expense for the years ended December 31, 2020, 2019, and 2018 were $(1) million, $1 million and $4 million, respectively.

POSTEMPLOYMENT AND POSTRETIREME

POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS	Pension Plans The Company sponsors defined benefit pension plans. Under the plans, pension benefits are based on an employee’s years of service and, for certain categories of employees, qualifying compensation. Company contributions to these pension plans are determined by an independent actuary to meet or exceed minimum funding requirements. In our U.S. plan, the unrecognized cost of any retroactive amendments and actuarial gains and losses are amortized over the average remaining life expectancy of inactive participants. In all of our Non-U.S plans, the unrecognized cost of any retroactive amendments and actuarial gains and losses are amortized over the average future service period of plan participants expected to receive benefits. During 2019, the Company completed balance sheet risk mitigation actions related to certain U.S. and non-U.S. pension plans. These actions included the purchase of non-participating annuity contracts from insurance companies and the payment of lump sums to retirees, which resulted in the settlement of liabilities to affected participants. As a result of these transactions, the Company recognized pension settlement losses of $43 million during the twelve months ended December 31, 2019. These losses are included in Non-operating expense (income) on the Consolidated Statements of Earnings (Loss) in our Corporate, Other and Eliminations category. These transactions did not have a material effect on the plans' funded status. The following tables provide a reconciliation of the change in the projected benefit obligation, the change in plan assets and the net amount recognized in the Consolidated Balance Sheets (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 866 $ 475 $ 1,341 $ 891 $ 427 $ 1,318 Service cost 5 5 10 5 5 10 Interest cost 28 10 38 34 13 47 Actuarial loss 83 28 111 85 42 127 Currency loss — 18 18 — 13 13 Benefits paid (71) (16) (87) (45) (18) (63) Plan amendments — 3 3 — — — Settlements/curtailments (1) (4) (5) (104) (7) (111) Other — 4 4 — — — Benefit obligation at end of period $ 910 $ 523 $ 1,433 $ 866 $ 475 $ 1,341 December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Plan Assets Fair value of assets at beginning of period $ 733 $ 386 $ 1,119 $ 727 $ 328 $ 1,055 Actual return on plan assets 80 37 117 130 50 180 Currency gain — 14 14 — 11 11 Company contributions 101 21 122 25 21 46 Benefits paid (71) (16) (87) (45) (18) (63) Settlements/curtailments (1) (4) (5) (104) (5) (109) Other — 3 3 — (1) (1) Fair value of assets at end of period $ 842 $ 441 $ 1,283 $ 733 $ 386 $ 1,119 Funded status $ (68) $ (82) $ (150) $ (133) $ (89) $ (222) December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 12 $ 12 $ — $ 11 $ 11 Accrued pension cost – current — (2) (2) — (2) (2) Accrued pension cost – non-current (68) (92) (160) (133) (98) (231) Net amount recognized $ (68) $ (82) $ (150) $ (133) $ (89) $ (222) Amounts Recorded in AOCI Net actuarial loss $ (381) $ (109) $ (490) $ (345) $ (97) $ (442) For the year ended December 31, 2020, the actuarial loss of $111 million was largely the result of decreases in discount rates across all plans. In the U.S. plan, the actuarial loss was primarily driven by the decrease in the discount rate. Additionally, updated mortality assumptions and a decrease in the cash balance interest crediting rate negatively impacted the projected benefit obligation (PBO). In the Non-U.S. plans, the actuarial loss was driven by a decrease in the discount rate of the U.K. and other plans, partially offset by inflation. For the year ended December 31, 2019, the actuarial loss of $127 million was largely the result of decreases in discount rates across all plans. In the U.S. plans, the actuarial loss was primarily driven by a decrease in the discount rate. In the Non-U.S. plans, the actuarial loss was driven by a decrease in the discount rate of the U.K. and other plans, partially offset by inflation. The following table presents information about the projected benefit obligation, accumulated benefit obligation (ABO) and plan assets of the Company’s pension plans (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with PBO in excess of fair value of plan assets: Projected benefit obligation $ 910 $ 364 $ 1,274 $ 866 $ 329 $ 1,195 Fair value of plan assets $ 842 $ 270 $ 1,112 $ 733 $ 229 $ 962 Plans with ABO in excess of fair value of plan assets: Accumulated benefit obligation $ 910 $ 330 $ 1,240 $ 866 $ 295 $ 1,161 Fair value of plan assets $ 842 $ 249 $ 1,091 $ 733 $ 205 $ 938 Weighted-Average Assumptions Used to Determine Benefit Obligation The following table presents weighted average assumptions used to determine benefit obligations at the measurement dates: December 31, 2020 2019 United States Plans Discount rate 2.50 % 3.30 % Expected return on plan assets 4.75 % 6.50 % Cash balance interest crediting rate 0.79 % 2.66 % Non-United States Plans Discount rate 1.73 % 2.24 % Expected return on plan assets 4.08 % 4.66 % Rate of compensation increase 3.00 % 3.99 % Components of Net Periodic Pension Cost (Income) The following table presents the components of net periodic pension cost (income) (in millions): Twelve Months Ended December 31, 2020 2019 2018 Service cost $ 10 $ 10 $ 12 Interest cost 38 47 47 Expected return on plan assets (62) (68) (73) Amortization of actuarial loss 15 15 15 Settlement/curtailment 1 44 — Net periodic pension cost $ 2 $ 48 $ 1 Weighted-Average Assumptions Used to Determine Net Periodic Pension Cost The following table presents weighted-average assumptions used to determine net periodic pension costs for the periods noted: Twelve Months Ended December 31, 2020 2019 2018 United States Plans Discount rate 3.30 % 4.25 % 3.55 % Expected return on plan assets 6.50 % 6.75 % 6.75 % Cash balance interest crediting rate 2.66 % 3.77 % 3.10 % Rate of compensation increase N/A (a) N/A (a) N/A (a) Non-United States Plans Discount rate 2.24 % 3.04 % 2.88 % Expected return on plan assets 4.66 % 4.91 % 5.22 % Rate of compensation increase 3.99 % 4.14 % 4.29 % (a) Not applicable due to changes in plan made on August 1, 2009 that were effective beginning January 1, 2010. The expected return on plan assets assumption is derived by taking into consideration the target plan asset allocation, historical rates of return on those assets, projected future asset class returns and net outperformance of the market by active investment managers. An asset return model is used to develop an expected range of returns on plan investments over a 20 year period, with the expected rate of return selected from a best estimate range within the total range of projected results. The result is then rounded down to the nearest 25 basis points. Items Measured at Fair Value The Company classifies and discloses pension plan assets in one of the following three categories: Level 1: Quoted market prices in active markets for identical assets. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. Plan Assets The tables in this section show pension plan asset fair values and fair value leveling information. The assets are categorized into one of the three levels of the fair value hierarchy or are not subject to leveling, in the case of investments that are valued using the net asset value per share (or its equivalent) practical expedient ("NAV"). The following table summarizes the fair values and applicable fair value hierarchy levels of United States pension plan assets (in millions): December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 53 $ — $ — $ 53 Fixed income and cash equivalents: Corporate bonds 31 288 — 319 Government debt — 68 — 68 Total United States plan assets subject to leveling $ 84 $ 356 $ — 440 Plan assets measured at NAV: Equities 193 Fixed income and cash equivalents 157 Absolute return strategies 52 Total United States plan assets $ 842 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 57 $ — $ — $ 57 International 55 — — 55 Fixed income and cash equivalents: Corporate bonds 28 214 — 242 Government debt — 85 — 85 Real estate investment trusts 22 — — 22 Total United States plan assets subject to leveling $ 162 $ 299 $ — 461 Plan assets measured at NAV: Equities 130 Real assets 62 Fixed income and cash equivalents 33 Absolute return strategies 47 Total United States plan assets $ 733 The following table summarizes the fair values and applicable fair value hierarchy levels of non-United States pension plan assets (in millions): December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 2 $ — $ 2 Cash and cash equivalents — 81 — 81 Fixed income — 9 — 9 Total non-United States plan assets subject to leveling $ — $ 92 $ — 92 Plan assets measured at NAV: Equities 86 Fixed income and cash equivalents 156 Absolute return strategies and other 107 Total non-United States plan assets $ 441 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents: Cash and cash equivalents — 65 — 65 Corporate bonds — 13 — 13 Total non-United States plan assets subject to leveling $ — $ 82 $ — 82 Plan assets measured at NAV: Equities 71 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 386 Investment Strategy The current targeted asset allocation for the United States pension plan is to have 28.5% of assets invested in equities, 65.5% in intermediate and long-term fixed income securities and 6% in absolute return strategies. Assets are rebalanced quarterly to conform to policy tolerances. The Company actively evaluates the reasonableness of its asset mix given changes in the projected benefit obligation and market dynamics. Our investment policy and asset mix for the non-United States pension plans varies by location and is based on projected benefit obligation and market dynamics. Estimated Future Benefit Payments The following table shows estimated future benefit payments from the Company’s pension plans (in millions): Year Estimated Benefit Payments 2021 $ 82 2022 $ 78 2023 $ 78 2024 $ 79 2025 $ 76 2026-2030 $ 376 Contributions The Company does not expect to contribute to the U.S. pension plan during 2021. The Company expects to contribute $25 million in cash to non-U.S. plans during 2021. Actual contributions to the plans may change as a result of a variety of factors, including changes in laws that impact funding requirements. Defined Contribution Plans The Company sponsors two defined contribution plans which are available to substantially all United States employees. The Company matches a percentage of employee contributions up to a maximum level and contributes up to 2% of an employee’s wages regardless of employee contributions. The Company recognized expense of $48 million during the years ended December 31, 2020, 2019 and 2018, related to these plans. The Company maintains health care and life insurance benefit plans for certain retired employees and their dependents. The health care plans in the United States are non-funded and pay either (1) stated percentages of covered medically necessary expenses, after subtracting payments by Medicare or other providers and after stated deductibles have been met, or (2) fixed amounts of medical expense reimbursement. Salaried employees hired on or before December 31, 2005 become eligible to participate in the United States health care plans upon retirement if they have accumulated 10 years of service after age 45, 48 or 50, depending on the category of employee. For employees hired after December 31, 2005, the Company does not provide subsidized retiree health care. Some of the plans are contributory, with some retiree contributions adjusted annually. The Company has reserved the right to change or eliminate these benefit plans subject to the terms of collective bargaining agreements. The following table provides a reconciliation of the change in the projected benefit obligation and the net amount recognized in the Consolidated Balance Sheets for the years ended December 31, 2020 and 2019 (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 169 $ 14 $ 183 $ 183 $ 12 $ 195 Service cost 1 — 1 1 — 1 Interest cost 5 1 6 7 1 8 Actuarial loss/(gain) — 1 1 (7) 2 (5) Currency gain — (1) (1) — — — Plan amendments — — — (1) — (1) Benefits paid (12) (1) (13) (14) (1) (15) Benefit obligation at end of period $ 163 $ 14 $ 177 $ 169 $ 14 $ 183 Funded status $ (163) $ (14) $ (177) $ (169) $ (14) $ (183) Amounts Recognized in the Consolidated Balance Sheets Accrued benefit obligation – current $ (13) $ (1) $ (14) $ (15) $ (1) $ (16) Accrued benefit obligation – non-current (150) (13) (163) (154) (13) $ (167) Net amount recognized $ (163) $ (14) $ (177) $ (169) $ (14) $ (183) Amounts Recorded in AOCI Net actuarial gain $ 41 $ 2 $ 43 $ 48 $ 3 $ 51 Net prior service credit 2 — 2 6 — 6 Net amount recognized $ 43 $ 2 $ 45 $ 54 $ 3 $ 57 The following table presents information about the accumulated postretirement benefit obligation (APBO) and plan assets of the Company's postretirement benefit plans (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with APBO in excess of fair value of plan assets: Accumulated postretirement benefit obligation $ 163 $ 14 $ 177 $ 169 $ 14 $ 183 Fair value of plan assets $ — $ — $ — $ — $ — $ — Weighted-Average Assumptions Used to Determine Benefit Obligations The following table presents the discount rates used to determine the benefit obligations: December 31, 2020 2019 United States plans 2.25 % 3.10 % Non-United States plans 3.04 % 3.84 % Components of Net Periodic Postretirement Benefit Cost (Income) The following table presents the components of net periodic postretirement benefit cost (income) (in millions): Twelve Months Ended December 31, 2020 2019 2018 Service cost $ 1 $ 1 $ 1 Interest cost 6 8 8 Amortization of prior service credit (4) (4) (4) Amortization of actuarial gain (8) (8) (6) Net periodic postretirement benefit income $ (5) $ (3) $ (1) Weighted-Average Assumptions Used to Determine Net Periodic Postretirement Benefit Cost The following table presents the discount rates used to determine net periodic postretirement benefit cost: Twelve Months Ended December 31, 2020 2019 2018 United States plans 3.10 % 4.15 % 3.45 % Non-United States plans 3.84 % 4.59 % 4.56 % The following table presents health care cost trend rates used to determine net periodic postretirement benefit cost, as well as information regarding the ultimate rate and the year in which the ultimate rate is reached: Twelve Months Ended December 31, 2020 2019 2018 United States plans: Initial rate at end of year 8.20 % 6.50 % 6.75 % Ultimate rate 4.50 % 5.00 % 5.00 % Year in which ultimate rate is reached 2029 2026 2026 Non-United States plans: Initial rate at end of year 4.10 % 5.45 % 5.40 % Ultimate rate 3.90 % 5.45 % 5.40 % Year in which ultimate rate is reached 2040 2019 2019 Estimated Future Benefit Payments The following table shows estimated future benefit payments from the Company’s postretirement benefit plans (in millions): Year Estimated Benefit Payments 2021 $ 14 2022 $ 14 2023 $ 13 2024 $ 13 2025 $ 12 2026-2030 $ 55 Postemployment Benefits The Company may also provide benefits to former or inactive employees after employment but before retirement under certain conditions. These benefits include continuation of benefits such as health care and life insurance coverage. The accrued postemployment benefits liability at December 31, 2020 and 2019 was $8 million and $11 million, respectively. The net periodic postemployment benefit (income)/expense for the years ended December 31, 2020, 2019, and 2018 were $(1) million, $1 million and $4 million, respectively.

CONTINGENT LIABILITIES AND OTHE

CONTINGENT LIABILITIES AND OTHER MATTERS	12 Months Ended
	Dec. 31, 2020
Loss Contingency [Abstract]
CONTINGENT LIABILITIES AND OTHER MATTERS	The Company may be involved in various legal and regulatory proceedings relating to employment, antitrust, tax, product liability, environmental, contracts, intellectual property and other matters (collectively, “Proceedings”). The Company regularly reviews the status of such Proceedings along with legal counsel. Liabilities for such Proceedings are recorded when it is probable that the liability has been incurred and when the amount of the liability can be reasonably estimated. Liabilities are adjusted when additional information becomes available. Management believes that the amount of any reasonably possible losses in excess of any amounts accrued, if any, with respect to such Proceedings or any other known claim, including the matters described below under the caption Environmental Matters (the “Environmental Matters”), are not material to the Company’s financial statements. Management believes that the ultimate disposition of the Proceedings and the Environmental Matters will not have a material adverse effect on the Company’s financial condition. While the likelihood is remote, the disposition of the Proceedings and Environmental Matters could have a material impact on the results of operations, cash flows or liquidity in any given reporting period. Litigation and Regulatory Proceedings The Company is involved in litigation and regulatory proceedings from time to time in the regular course of its business. The Company believes that adequate provisions for resolution of all contingencies, claims and pending matters have been made for probable losses that are reasonably estimable. Environmental Matters The Company has established policies and procedures designed to ensure that its operations are conducted in compliance with all relevant laws and regulations and that enable the Company to meet its high standards for corporate sustainability and environmental stewardship. Our manufacturing facilities are subject to numerous foreign, federal, state and local laws and regulations relating to the presence of hazardous materials, pollution and protection of the environment, including emissions to air, reductions of greenhouse gases, discharges to water, management of hazardous materials, handling and disposal of solid wastes, use of chemicals in our manufacturing processes, and remediation of contaminated sites. All Company manufacturing facilities operate using an ISO 14001 or equivalent environmental management system. The Company’s 2030 Sustainability Goals include significant global reductions in energy use, water consumption, waste to landfill, and emissions of greenhouse gases, fine particulate matter and volatile organic air emissions, and protection of biodiversity.

STOCK COMPENSATION

STOCK COMPENSATION	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
STOCK COMPENSATION	Description of the Plan On April 18, 2019, the Company's stockholders approved the Owens Corning 2019 Stock Plan (the "2019 Stock Plan") which replaced the 2016 Stock Plan. The 2019 Stock Plan authorizes grants of stock options, stock appreciation rights, restricted stock awards, restricted stock units, bonus stock awards, performance stock awards and performance stock units. At December 31, 2020, the number of shares remaining available under the 2019 Stock Plan for all stock awards was 3.5 million. Prior to 2019, employees were eligible to receive stock awards under the Owens Corning 2016 Stock Plan and the Owens Corning 2013 Stock Plan. Total Stock-Based Compensation Expense Stock-based compensation expense included in Marketing and administrative expenses in the accompanying Consolidated Statements of Earnings (Loss) is as follows (in millions): Twelve Months Ended December 31, 2020 2019 2018 Total stock-based compensation expense $ 41 $ 39 $ 47 Income tax benefit recognized on stock-based compensation expense $ 14 $ 7 $ 24 Stock Options The Company has granted stock options under its stockholder approved stock plans. The Company calculates a weighted-average grant-date fair value using a Black-Scholes valuation model for options granted. Compensation expense for options is measured based on the fair market value of the option on the date of grant, and is recognized on a straight-line basis over a four The Company has not granted stock options since the year ended December 31, 2014. As of December 31, 2020, there was no unrecognized compensation cost related to stock options and the range of exercise prices on outstanding stock options was $33.73 — $42.16. The following table summarizes the Company’s stock option activity in 2020: Weighted-Average Number of Options Exercise Price Remaining Intrinsic Value (in millions) Outstanding, December 31, 2019 414,800 $ 37.79 3.06 $ 11 Exercised (53,025) 37.90 Outstanding, December 31, 2020 361,775 $ 37.77 1.50 $ 14 Exercisable, December 31, 2020 361,775 $ 37.77 1.50 $ 14 The total intrinsic value of stock options exercised and the resulting tax benefits received were as follows (in millions): Twelve Months Ended December 31, 2020 2019 2018 Cash received upon exercise of stock option awards $ 2 $ 2 $ 1 Income tax benefit received for stock option awards exercised $ — $ — $ — Restricted Stock Awards and Restricted Stock Units The Company has granted restricted stock awards and restricted stock units (collectively referred to as “RSUs”) under its stockholder approved stock plans. Compensation expense for restricted stock is measured based on the closing market price of the stock at date of grant and is recognized on a straight-line basis over the vesting period, which is typically three or four The weighted average grant date fair value of RSUs granted in 2020, 2019 and 2018 was $63.96, $52.60 and $84.34, respectively. The following table shows a summary of the Company’s RSU plans: Number of Weighted- Balance at January 1, 2020 1,515,706 $ 51.70 Granted 513,111 63.96 Vested (515,247) 51.50 Forfeited (94,116) 67.09 Balance at December 31, 2020 1,419,454 $ 54.99 As of December 31, 2020, there was $32 million of total unrecognized compensation cost related to RSUs. That cost is expected to be recognized over a weighted-average period of 2.31 years. The total grant date fair value of shares vested during the years ended December 31, 2020, 2019 and 2018 was $27 million, $21 million and $23 million, respectively. Performance Stock Awards and Performance Stock Units The Company has granted performance stock awards and performance stock units (collectively referred to as “PSUs”) as a part of its long-term incentive plan. All outstanding performance grants will fully settle in stock. The amount of stock ultimately distributed from the 2020, 2019 and 2018 grants is contingent on meeting internal company-based metrics or an external-based stock performance metric. In 2020, 2019 and 2018, the Company granted both internal company-based and external-based metric PSUs. Internal Company-based metrics The internal company-based metrics vest after a three-year period and are based on various company-based metrics over a three The initial fair value for all internal company-based metric PSUs assumes that the performance goals will be achieved and is based on the grant date stock price. This assumption is monitored quarterly and if it becomes probable that such goals will not be achieved or will be exceeded, compensation expense recognized will be adjusted and previous surplus compensation expense recognized will be reversed or additional expense will be recognized. The expected term represents the period from the grant date to the end of the three-year performance period. Pro-rata vesting may be utilized in the case of death, disability or retirement, and awards, if earned, will be paid at the end of the three-year period. External based metrics The external-based metrics vest after a three The following table provides a range of these assumptions: Twelve Months Ended December 31, 2020 2019 2018 Expected volatility 28.43% — 44.83% 26.67 % 24.56 % Risk free interest rate 0.15% — 1.43% 2.45 % 2.22 % Expected term (in years) 2.31 — 2.90 2.90 2.92 Grant date fair value of units granted $68.60 — $76.58 $ 68.65 $ 94.14 The risk-free interest rate was based on zero coupon United States Treasury bills at the grant date. The expected term represents the period from the grant date to the end of the three-year performance period. PSU Summary As of December 31, 2020, there was $13 million total unrecognized compensation cost related to PSUs. That cost is expected to be recognized over a weighted-average period of 1.82 years. The total grant date fair value of shares vested during the years ended December 31, 2020, 2019 and 2018, was $9 million, $14 million and $23 million, respectively. The following table shows a summary of the Company's PSU plans: Number of Weighted- Average Grant Date Fair Value Balance as of January 1, 2020 312,725 $ 69.23 Granted 169,539 65.29 Vested (98,842) 95.43 Forfeited (60,061) 74.09 Balance as of December 31, 2020 323,361 $ 69.20 Employee Stock Purchase Plan The Owens Corning Employee Stock Purchase Plan (ESPP) is a tax qualified plan under Section 423 of the Internal Revenue Code. The purchase price of shares purchased under the ESPP is equal to 85% of the lower of the fair market value of shares of Owens Corning common stock at the beginning or ending of the offering period, which is a six month period ending on May 31 and November 30 of each year. On April 16, 2020, the Company's stockholders approved the Amended and Restated Owens Corning Employee Stock Purchase Plan which increased the number of shares available for issuance under the plan by 4.2 million shares. As of December 31, 2020, 4.1 million shares remain available for purchase.

CHANGES IN ACCUMULATED OTHER CO

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT	The following table summarizes the changes in accumulated other comprehensive income (deficit) (in millions): Twelve Months Ended December 31, 2020 2019 Currency Translation Adjustment Beginning balance $ (282) $ (306) Net investment hedge amounts classified into AOCI, net of tax 11 13 Gain on foreign currency translation 51 11 Other comprehensive income, net of tax 62 24 Ending balance $ (220) $ (282) Pension and Other Postretirement Adjustment Beginning balance $ (326) $ (350) Amounts reclassified from AOCI to net earnings, net of tax (a) 3 35 Amounts classified into AOCI, net of tax (49) (11) Other comprehensive (loss)/income, net of tax (46) 24 Ending balance $ (372) $ (326) Hedging Adjustment Beginning balance $ (2) $ — Amounts reclassified from AOCI to net earnings, net of tax (b) 4 3 Amounts classified into AOCI, net of tax 2 (5) Other comprehensive income/(loss), net of tax 6 (2) Ending balance $ 4 $ (2) Total AOCI ending balance $ (588) $ (610) (a) These AOCI components are included in the computation of total Pension and Other Postretirement cost and are recorded in Non-operating expense (income). See Notes 12 and 13 for additional information. (b) Amounts reclassified from (loss)/gain on cash flow hedges are reclassified from AOCI to income when the hedged item affects earnings and is recognized in Cost of sales or Interest expense, net depending on the hedged item. See Note 4 for additional information.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
EARNINGS PER SHARE	The following table is a reconciliation of weighted-average shares for calculating basic and diluted earnings (loss) per-share (in millions, except per share amounts): Twelve Months Ended December 31, 2020 2019 2018 Net earnings (loss) attributable to Owens Corning $ (383) $ 405 $ 545 Weighted-average number of shares outstanding used for basic earnings (loss) per share 108.6 109.2 110.4 Non-vested restricted and performance shares — 0.7 0.8 Options to purchase common stock — 0.2 0.2 Weighted-average number of shares outstanding and common equivalent shares used for diluted earnings (loss) per share 108.6 110.1 111.4 Earnings (loss) per common share attributable to Owens Corning common stockholders: Basic $ (3.53) $ 3.71 $ 4.94 Diluted $ (3.53) $ 3.68 $ 4.89 Basic earnings (loss) per share is calculated by dividing earnings (loss) attributable to Owens Corning by the weighted-average number of shares of the Company’s common stock outstanding during the period. Outstanding shares consist of issued shares less treasury stock. On December 3, 2020, the Board of Directors approved a new share buy-back program under which the Company is authorized to repurchase up to 10 million shares of the Company’s outstanding common stock (the “2020 Repurchase Authorization"). The 2020 Repurchase Authorization is in addition to the share buy-back program announced October 24, 2016 (the 2016 Repurchase Authorization and collectively with the 2020 Repurchase Authorization, the "Repurchase Authorization"). The Repurchase Authorization enables the Company to repurchase shares through the open market, privately negotiated, or other transactions. The actual number of shares repurchased will depend on timing, market conditions and other factors and is at the Company’s discretion. The Company repurchased 4.1 million shares of its common stock for $292 million for the year ended December 31, 2020 under the Repurchase Authorization. As of December 31, 2020, 9.5 million shares remain available for repurchase under the Repurchase Authorization.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	The following table summarizes our Earnings (loss) before taxes and Income tax expense (in millions): Twelve Months Ended December 31, 2020 2019 2018 Earnings before taxes: United States $ 8 $ 315 $ 411 Foreign (264) 275 293 Total $ (256) $ 590 $ 704 Income tax expense: Current United States $ 4 $ (4) $ (10) State and local 16 11 6 Foreign 30 60 19 Total current 50 67 15 Deferred United States 64 112 114 State and local (1) 11 12 Foreign 16 (4) 15 Total deferred 79 119 141 Total income tax expense $ 129 $ 186 $ 156 The reconciliation between the United States federal statutory rate and the Company’s effective income tax rate from continuing operations is: Twelve Months Ended December 31, 2020 2019 2018 United States federal statutory rate 21 % 21 % 21 % State and local income taxes, net of federal tax benefit (9) 3 2 U.S. tax expense on foreign earnings (5) 1 2 Legislative tax rate changes 7 2 — Foreign tax credits 2 — — Valuation allowance (15) 3 2 Intercompany restructuring - intellectual property transfer 14 — — Goodwill impairment charge (75) — — Uncertain tax positions and settlements 2 — (5) Excess tax benefits related to stock compensation 2 — (2) Other, net 6 1 2 Effective tax rate (50) % 31 % 22 % In the first quarter of 2020, the company recorded non-cash impairment charges related to the impairment of goodwill and certain other indefinite-lived intangible assets which were largely non-deductible resulting in a substantial negative impact to our effective tax rate. In addition, non-cash charges were recorded in 2020 related to valuation allowance adjustments against certain deferred tax assets recorded in our French, Indian and Other foreign legal entities due to volatility in the markets we serve from the COVID-19 pandemic. In December 2020, the company completed an intercompany restructuring that resulted in the transfer of certain intellectual property rights, held by wholly owned foreign subsidiaries, to the U.S. The intellectual property rights transferred to the US resulted in a step-up in the tax basis for U.S. tax purposes which resulted in the company recognizing a deferred tax asset of $37 million and a current year tax expense of $5 million. The recognized tax benefit of $37 million is amortizable for US tax purposes over a fifteen-year period. On July 20, 2020 the Internal Revenue Service (IRS) issued final regulations under IRC Section 951A permitting a taxpayer to elect to exclude, from its inclusion of global intangible low-taxed income (GILTI), income subject to a high foreign effective tax rate. As a result of the final regulations, the company recorded a net non-cash income tax benefit of $13 million in the third quarter relating to the 2018 and 2019 tax years. On March 6, 2019, the U.S. Treasury and the IRS proposed regulations that provide guidance on determining the amount of a domestic corporation’s deduction for GILTI and foreign-derived intangible income (FDII) added by the U.S. Tax Cuts and Jobs Act of 2017 (the "Tax Act"). The proposed regulations provide special rules to determine the deduction amount, which adjusted the Company’s 2018 tax estimate and resulted in an increase to tax expense of $12 million for 2019. Effective January 1, 2018, the Tax Act created a new requirement to include GILTI earned by controlled foreign corporations (CFCs) in U.S. income. The GILTI must be included currently in the gross income of the CFCs’ U.S. shareholder. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). During the first quarter of 2018, we selected the period cost method in recording the tax effects of GILTI in our financial statements. In February 2018, the FASB issued ASU 2018-02 “Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income”, which provides companies with an option to reclassify stranded tax effects resulting from enactment of the Tax Act from Accumulated other comprehensive income to Accumulated earnings. The standard was effective for the Company starting January 1, 2019. The Company has elected not to reclassify the income tax effects of the Tax Act from Accumulated other comprehensive income to Accumulated earnings. The Company continues to assert indefinite reinvestment in accordance with ASC 740 based on the laws as of enactment of the Tax Act. As of December 31, 2020, the Company has not provided for withholding or income taxes on approximately $1.2 billion of undistributed reserves of its foreign subsidiaries and affiliates as they are considered by management to be permanently reinvested. Quantification of the deferred tax liability associated with these undistributed reserves is not practicable. The cumulative temporary differences giving rise to the deferred tax assets and liabilities are as follows (in millions): December 31, 2020 December 31, 2019 Deferred Deferred Deferred Deferred Other employee benefits $ 71 $ — $ 76 $ — Pension plans 41 — 54 — Operating loss and tax credit carryforwards 170 — 195 — Depreciation — 259 — 247 Leases - Right of Use Assets — 33 — 49 Leases - Liability 33 — 49 — Amortization — 333 — 388 Foreign tax credits 49 — 97 — State and local taxes — — 3 — Other 90 — 76 — Subtotal 454 625 550 684 Valuation allowances (133) — (92) — Total deferred taxes $ 321 $ 625 $ 458 $ 684 The following table summarizes the amount and expiration dates of our deferred tax assets related to operating loss and credit carryforwards at December 31, 2020 (in millions): Expiration Amounts U.S. federal loss carryforwards 2036 $ 23 U.S. state loss carryforwards (a) 2021 – 2034 37 Foreign loss and tax credit carryforwards Indefinite 41 Foreign loss and tax credit carryforwards (a) 2021 – 2039 66 Other U.S. federal and state tax credits 2028 – 2034 3 Total operating loss and tax credit carryforwards $ 170 U.S foreign tax credits 2027 $ 49 (a) As of December 31, 2020, $12 million of U.S. state and $7 million of foreign deferred tax assets related to loss carryforwards that are set to expire over the next three years. At December 31, 2020, the Company had federal, state and foreign net operating loss (NOL) carryforwards of $111 million, $1,160 million and $418 million, respectively. In order to utilize our NOLs, the Company will need to generate federal, state, and foreign earnings before taxes of approximately $111 million, $1,115 million, and $395 million, respectively. Certain of these loss carryforwards are subject to limitation as a result of the acquisition of certain foreign entities in 2007. However, the Company believes that these limitations on its loss carryforwards will not result in a forfeiture of any of the carryforwards. Deferred income taxes are provided for temporary differences between amounts of assets and liabilities for financial reporting purposes and the basis of such assets and liabilities as measured under enacted tax laws and regulations, as well as NOLs, tax credits and other carryforwards. A valuation allowance will be recorded to reduce deferred tax assets if, based on all available evidence, it is considered more likely than not that some portion or all of the recorded deferred tax assets will not be realized in future periods. To the extent the reversal of deferred tax liabilities is relied upon in our assessment of the realizability of deferred tax assets, they will reverse in the same period and jurisdiction as the temporary differences giving rise to the deferred tax assets. As of December 31, 2020, the Company had federal net deferred tax liabilities before valuation allowances of $140 million, state net deferred tax liabilities of $1 million, and foreign net deferred tax liabilities of $31 million. The valuation allowance of $133 million as of December 31, 2020 is related to tax assets of $49 million, $7 million and $77 million for U.S. federal FTCs and certain state and foreign jurisdictions, respectively. The realization of deferred tax assets depends on achieving a certain minimum level of future taxable income. Management currently believes that it is at least reasonably possible that the minimum level of taxable income will be met within the next 12 months to reduce the valuation allowance of certain foreign jurisdictions by a range of zero to $9 million. The valuation allowance of $92 million as of December 31, 2019 is related to tax assets of $43 million, $11 million, and $38 million for U.S. federal FTC's and certain state and foreign jurisdictions, respectively. The Company, or one of its subsidiaries, files income tax returns in the United States and other foreign jurisdictions. The Company is no longer subject to U.S. federal tax examinations for years before 2017 or state and foreign examinations for years before 2010. Due to the potential for resolution of federal, state and foreign examinations, and the expiration of various statutes of limitation, it is reasonably possible that the gross unrecognized tax benefits balance may change within the next 12 months by a range of zero to $4 million. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in millions): Twelve Months Ended December 31, 2020 2019 2018 Balance at beginning of period $ 79 $ 84 $ 90 Tax positions related to the current year Gross additions — — 6 Tax positions related to prior years Gross additions 2 1 36 Gross reductions (1) — (37) Settlements (1) (1) (5) Expiration of statute of limitations (3) (5) (4) Impact of currency changes — — (2) Balance at end of period $ 76 $ 79 $ 84 If these uncertain tax benefits (UTBs) were to be recognized as of December 31, 2020, the Company’s income tax expense would decrease by about $59 million. The Company classifies all interest and penalties as income tax expense. As of December 31, 2020, 2019 and 2018, and for the periods then ended, the Company recognized $7 million, $8 million and $10 million, respectively, in liabilities for tax related interest and penalties on its Consolidated Balance Sheets and less than $1 million, $2 million and $1 million, respectively, of interest and penalty expense on its Consolidated Statements of Earnings (Loss). On February 5, 2018, the Company acquired all the outstanding equity of Paroc, a leading producer of mineral wool insulation for building and technical applications in Europe. The acquisition included net uncertain tax benefits (UTBs) related to a transfer pricing dispute and interest expense. On December 18, 2018, the Finnish Supreme Administrative Court (SAC) ruled in favor of Paroc Oy Ag, a wholly-owned subsidiary of the Company, regarding the transfer pricing dispute for tax years 2006 to 2008. Based on the SAC decision, the Company reduced the UTB regarding the transfer pricing dispute by $32 million and recorded a corresponding benefit to income tax expense.

SCHEDULE II - VALUATION AND QUA

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES [Disclosure]	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS AND RESERVES FOR THE YEARS ENDED DECEMBER 31, 2020, 2019 AND 2018 (in millions) Balance at Beginning of Period Charged to Costs and Expenses Charged to Other Accounts Deductions Acquisitions and Divestitures Balance at End of Period FOR THE YEAR ENDED DECEMBER 31, 2020 Allowance for doubtful accounts $ 11 $ 1 $ — $ (2) (a) $ — $ 10 Tax valuation allowance $ 92 $ 39 $ 2 $ — $ — $ 133 FOR THE YEAR ENDED DECEMBER 31, 2019 Allowance for doubtful accounts $ 16 $ 2 $ — $ (7) (a) $ — $ 11 Tax valuation allowance $ 78 $ 19 $ 1 $ (6) $ — $ 92 FOR THE YEAR ENDED DECEMBER 31, 2018 Allowance for doubtful accounts $ 19 $ — $ — $ (4) (a) $ 1 $ 16 Tax valuation allowance $ 94 $ 13 $ (4) $ (31) $ 6 $ 78 (a) Uncollectible accounts written off, net of recoveries.

SCHEDULE II - VALUATION AND Q_2

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS AND RESERVES FOR THE YEARS ENDED DECEMBER 31, 2020, 2019 AND 2018 (in millions) Balance at Beginning of Period Charged to Costs and Expenses Charged to Other Accounts Deductions Acquisitions and Divestitures Balance at End of Period FOR THE YEAR ENDED DECEMBER 31, 2020 Allowance for doubtful accounts $ 11 $ 1 $ — $ (2) (a) $ — $ 10 Tax valuation allowance $ 92 $ 39 $ 2 $ — $ — $ 133 FOR THE YEAR ENDED DECEMBER 31, 2019 Allowance for doubtful accounts $ 16 $ 2 $ — $ (7) (a) $ — $ 11 Tax valuation allowance $ 78 $ 19 $ 1 $ (6) $ — $ 92 FOR THE YEAR ENDED DECEMBER 31, 2018 Allowance for doubtful accounts $ 19 $ — $ — $ (4) (a) $ 1 $ 16 Tax valuation allowance $ 94 $ 13 $ (4) $ (31) $ 6 $ 78 (a) Uncollectible accounts written off, net of recoveries.

BUSINESS AND SUMMARY OF SIGNI_2

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (POLICIES)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Accounting, Policy	Basis of Presentation Unless the context requires otherwise, the terms “Owens Corning,” “Company,” “we” and “our” in these notes refer to Owens Corning and its subsidiaries. The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States.
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements of the Company include the accounts of majority-owned subsidiaries. Intercompany accounts and transactions are eliminated.
Reclassifications	ReclassificationsCertain reclassifications have been made to the 2019 and 2018 Consolidated Financial Statements and Notes to the Consolidated Financial Statements to conform to the classifications used in 2020.
Use of Estimates and Assumptions	Use of Estimates and Assumptions The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and 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. Actual results could differ materially from those estimates.
Revenue Recognition	Revenue Recognition We recognize revenue as the amount of consideration that we expect to receive in exchange for transferring promised goods or services to customers. We do not adjust the transaction price for the effects of a significant financing component, as the time period between control transfer of goods and services and expected payment is one year or less. At the time of sale, we estimate provisions for different forms of variable consideration (discounts, rebates, returns and other refund liabilities) based on historical experience, current conditions and contractual obligations, as applicable. The estimated transaction price is typically not subject to significant reversals. We adjust these estimates when the most likely amount of consideration we expect to receive changes, although these changes are typically minor. Sales, value-added and other similar taxes that we collect are excluded from revenue. Many of our customer volume commitments are short-term and our performance obligations are generally limited to single purchase orders. Substantially all of our revenue is recognized at a point-in-time when control of goods transfers to the customer. Control transfer typically occurs when goods are shipped from our facilities or at other predetermined control transfer points (for instance, destination terms or consignment arrangements). Revenue Recognition (continued) We typically do not satisfy performance obligations without obtaining an unconditional right to payment from customers and, therefore, do not carry contract asset balances on the Consolidated Balance Sheets. Contract liability balances are recorded separately from receivables on the Consolidated Balance Sheets in either Total current liabilities or Other liabilities, depending on the timing of performance obligation satisfaction. We sell separately-priced warranties that extend certain product and workmanship coverages beyond our standard product warranty, which is described in Note 9. The up-front consideration on extended warranty contracts is deferred and recognized as revenue over time, based on the respective coverage period, ranging from 16 to 20 years. On an annual basis, we expect to recognize approximately $4 million of revenue associated with these extended warranty contracts. Additionally, in certain limited cases, we receive consideration before goods or services are transferred to the customer. These customer down payments and deposits are deferred, and typically recognized as revenue in the following quarter when we satisfy the related performance obligations. As of December 31, 2019, our contract liability balances (for extended warranties, down payments and deposits, collectively) totaled $60 million, of which $19 million was recognized as revenue throughout 2020. As of December 31, 2020, our contract liability balances totaled $66 million. As a practical expedient, we recognize incremental costs of obtaining a contract, if any, as an expense when incurred if the amortization period of the asset would have been one year or less. We do not have any costs to obtain or fulfill a contract that are capitalized under Accounting Standard Codification (ASC) 606.
Cost of Sales	Cost of Sales Cost of sales includes material, labor, energy and manufacturing overhead costs, including depreciation and amortization expense associated with the manufacture and distribution of the Company’s products. Provisions for warranties are provided in the same period that the related sales are recorded and are based on historical experience, current conditions and contractual obligations, as applicable. Distribution costs include inbound freight costs; purchasing and receiving costs; inspection costs; warehousing costs; shipping and handling costs, which include costs incurred relating to preparing, packaging, and shipping products to customers; and other costs of the Company’s distribution network. We account for shipping and handling activities that occur after control of the related good transfers as fulfillment activities instead of performance obligations. All shipping and handling costs billed to the customer are included as net sales in the Consolidated Statements of Earnings (Loss).
Marketing and Administrative Expenses	Marketing and Advertising ExpensesMarketing and advertising expenses are included in Marketing and administrative expenses. These costs include advertising and marketing communications, which are expensed the first time the advertisement takes place.
Science and Technology Expenses	Science and Technology Expenses The Company incurs certain expenses related to science and technology. These expenses include salaries, building and equipment costs, utilities, administrative expenses, materials and supplies associated with the improvement and development of the Company’s products and manufacturing processes. These costs are expensed as incurred.
Earnings per Share	Earnings per Share Basic earnings (loss) per share are computed using the weighted-average number of common shares outstanding during the period. Diluted earnings (loss) per share reflect the dilutive effect of common equivalent shares and increased shares that would result from the conversion of equity securities. The effects of anti-dilution are not presented.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted CashThe Company defines cash and cash equivalents as cash and time deposits with maturities of three months or less when purchased.
Accounts Receivable	Accounts ReceivableTrade accounts receivable are recorded at the invoiced amount and do not bear interest. Consistent with the requirements of ASU 2016-13, "Financial Instruments - Credit Losses (Topic 236)," the allowance for doubtful accounts is based on the Company’s assessment of the collectability of customer accounts. The Company regularly reviews the allowance by considering factors such as historical experience, credit quality, the age of the accounts receivable balances, and current economic conditions that may affect a customer’s ability to pay. Account balances are charged off against the allowance when the Company believes it is probable the receivable will not be recovered.
Inventory Valuation	Inventory Valuation Inventory costs include material, labor, and manufacturing overhead costs, including depreciation and amortization expense associated with the manufacture and distribution of the Company’s products. Inventories are stated at lower of cost or net realizable value and expense estimates are made for excess and obsolete inventories. Cost is determined by the first-in, first-out (“FIFO”) method.
Investments in Affiliates	Investments in AffiliatesThe Company accounts for investments in affiliates of 20% to 50% ownership when the Company does not have a controlling financial interest using the equity method under which the Company’s share of earnings and losses of the affiliate is reflected in earnings, and dividends are credited against the investment in affiliate when declared.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill assets are not amortized but are tested for impairment on at least an annual basis. In the current year, as part of the annual assessment, the Company used both a qualitative and quantitative approach to determine whether the fair value of a reporting unit was less than its carrying amount. Events and circumstances we consider in performing the qualitative assessment include macro-economic conditions, market and industry conditions, internal cost factors, and the overall financial performance of the reporting units. As part of our quantitative testing process for goodwill, the Company estimates fair values using a discounted cash flow approach from the perspective of a market participant. Significant assumptions used in the discounted cash flow approach are revenue growth rates and earnings before interest and taxes ("EBIT") margins used in estimating discrete period cash flow forecasts of the reporting unit, the discount rate, and the long-term revenue growth rate and EBIT margins used in estimating the terminal business value. The cash flow forecasts of the reporting units are based upon management’s long-term view of our markets and are the forecasts that are used by senior management and the Board of Directors to evaluate operating performance. The discount rate utilized is management’s estimate of what the market’s weighted average cost of capital is for a company with a similar debt rating and stock volatility, as measured by beta. The terminal business value is determined by applying the long-term growth rate to the latest year for which a forecast exists. As part of our goodwill quantitative testing process, we would evaluate whether there are reasonably likely changes to management’s estimates that would have a material impact on the results of the goodwill impairment testing. Other indefinite-lived intangible assets are not amortized but are tested for impairment on at least an annual basis or when determined to have a finite useful life. Substantially all of the indefinite-lived intangible assets are in trademarks and trade names. The Company uses the royalty relief approach to determine whether it is more likely than not that the fair value of these assets is less than its carrying amount. This review is performed annually, or when circumstances arise which indicate there may be impairment. When applying the royalty relief approach, the Company performs a discounted cash flow analysis based on the value derived from owning these trademarks and trade names and being relieved from paying royalty to third parties. Significant assumptions used include the discrete period revenue growth rates, royalty rates, discount rates, and terminal value. The inputs for the goodwill and indefinite-lived intangible tests are considered Level 3 inputs under the fair value hierarchy as they are the Company’s own data, and are unobservable in the marketplace. Indefinite-lived intangible assets purchased through acquisition are generally tested qualitatively for impairment in the first year following the acquisition before transitioning to the standard methodology described herein in subsequent years.
Properties and Depreciation	Properties and Depreciation Property, plant and equipment are stated at cost and depreciated over their estimated useful lives using the straight-line method. Property, plant and equipment accounts are relieved of the cost and related accumulated depreciation when assets are disposed of or otherwise retired. Precious metals used in our production tooling are included in property, plant and equipment and are depleted as they are consumed during the production process. Depletion typically represents an annual expense of less than 3% of the outstanding value and is recorded in Cost of sales on the Consolidated Statements of Earnings (Loss). The range of useful lives for the major components of the Company’s plant and equipment is as follows: Buildings and leasehold improvements 15 – 40 years Machinery and equipment Furnaces 4 – 15 years Information systems 5 – 10 years Equipment 5 – 20 years Expenditures for normal maintenance and repairs are expensed as incurred.
Asset Impairments	Asset Impairments The Company evaluates tangible and intangible long-lived assets for impairment when triggering events have occurred. This requires significant assumptions including projected cash flows, projected income tax rate and terminal business value. These inputs are considered Level 3 inputs under the fair value hierarchy as they are the Company’s own data, and are unobservable in the marketplace. Changes in management intentions, market conditions or operating performance could indicate that impairment charges might be necessary that could be material to the Company’s Consolidated Financial Statements in any given period. Please refer to Note 5 for additional detail on impairment charges recorded in 2020.
Income Taxes	Income TaxesThe Company recognizes current tax liabilities and assets for the estimated taxes payable or refundable on the tax returns for the current year. Deferred tax balances reflect the impact of temporary differences between the carrying amount of assets and liabilities and their tax basis. Amounts are stated at enacted tax rates expected to be in effect when taxes are actually paid or recovered. In addition, realization of certain deferred tax assets is dependent upon our ability to generate future taxable income. The Company records a valuation allowance to reduce its deferred tax assets to the amount that it believes is more likely than not to be realized. In addition, the Company estimates tax reserves to cover potential taxing authority claims for income taxes and interest attributable to audits of open tax years.
Taxes Collected From Customers and Remitted to Government Authorities and Taxes Paid to Vendors	Taxes Collected from Customers and Remitted to Government Authorities and Taxes Paid to Vendors Taxes are assessed by various governmental authorities at different rates on many different types of transactions. The Company charges sales tax or value-added tax (VAT) on sales to customers where applicable, as well as captures and claims back all available VAT that has been paid on purchases. VAT is recorded in separate payable or receivable accounts and does not affect revenue or cost of sales line items in the income statement. VAT receivable is recorded as a percentage of qualifying purchases at the time the vendor invoice is processed. VAT payable is recorded as a percentage of qualifying sales at the time an Owens Corning sale to a customer subject to VAT occurs. Amounts are paid to the taxing authority according to the method and collection prescribed by local regulations. Where applicable, VAT payable is netted against VAT receivable. The Company also pays sales tax to vendors who include a tax, required by government regulations, to the purchase price charged to the Company.
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits Accounting for pensions and other postretirement benefits involves estimating the cost of benefits to be provided well into the future and attributing that cost over the time period each employee works. To accomplish this, extensive use is made of assumptions about investment returns, discount rates, inflation, mortality, turnover and medical costs.
Derivative Financial Instruments	Derivative Financial Instruments The Company recognizes all derivative instruments as either assets or liabilities at fair value on the balance sheet. Please refer to Note 4 for further disclosure on derivatives. The Company performs an analysis for effectiveness of its derivatives designated as hedging instruments at the end of each quarter based on the terms of the contracts and the underlying items being hedged. The change in the fair value of cash flow hedges is deferred in Accumulated other comprehensive income (deficit) ("AOCI") and is subsequently recognized in Cost of sales (for commodity and foreign currency cash flow hedges) on the Consolidated Statements of Earnings (Loss) in order to mirror the location of the hedged items impacting earnings. Cash settlements for commodity and foreign currency hedges qualifying as cash flow hedges are included in Operating activities in the Consolidated Statements of Cash Flows. The Company has translation exposure resulting from translating the financial statements of foreign subsidiaries into U.S. Dollars, which is recognized in Currency translation adjustment (a component of AOCI). The Company uses cross-currency forward contracts to hedge a portion of the net investment in foreign subsidiaries against fluctuations in foreign exchange rates. The changes in fair values of these derivative instruments are recognized in Currency translation adjustment (a component of AOCI), with recognition of the excluded components amortized to Interest expense, net on the Consolidated Statements of Earnings (Loss). Cash settlements for derivatives qualifying as net investment hedges are included in Investing activities in the Consolidated Statements of Cash Flows.
Fair Value Measurements	Fair Value Measurements The carrying value of cash and cash equivalents, accounts receivable and short-term debt approximate fair value because of the short-term maturity of the instruments. The Company uses widely accepted valuation tools to determine fair value of our derivatives, such as discounting cash flows to calculate a present value for the derivatives. Our derivatives consist of natural gas forward swaps, cross currency swaps and foreign exchange forward contracts, all of which are over-the-counter and not traded through an exchange. The models use Level 2 inputs, such as forward curves and other commonly quoted observable transactions and prices. The fair value of our derivatives and hedging instruments are all classified as Level 2 investments within the three-tier hierarchy. Please refer to Notes 4 and 11 for additional fair value disclosure of derivative financial instruments and long-term debt, respectively.
Foreign Currency	Foreign CurrencyThe functional currency of the Company’s subsidiaries is generally the applicable local currency. Assets and liabilities of foreign subsidiaries are translated into United States Dollars at the period-end rate of exchange, and their Statements of Earnings and Statements of Cash Flows are converted on an ongoing basis at the monthly average rate. The resulting translation adjustment is included in AOCI in the Consolidated Balance Sheets and Consolidated Statements of Stockholders’ Equity. Transaction gains and losses that arise from exchange rate fluctuations on transactions denominated in a currency other than the functional currency are recorded in Other expenses, net in the Consolidated Statements of Earnings (Loss) as incurred.
Accounting Pronouncements	Accounting Pronouncements The following table summarizes recent accounting standard updates (ASU) issued by the Financial Accounting Standards Board (FASB) that could have an impact on the Company's Consolidated Financial Statements: Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Recently adopted standards: ASU 2018-14 "Compensation- Retirement Benefits- Defined Benefit Plans- General (Subtopic 715-20) This standard modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. January 1, 2020 We adopted this guidance using the retrospective approach for the year ended December 31, 2020. The adoption of this guidance did not have a material effect on our consolidated financial statements. Please refer to Notes 12 and 13 for relevant disclosure requirements. ASU 2016-13 "Financial Instruments - Credit Losses (Topic 326)," as amended by ASU 2018-19, 2019-04, 2019-05, 2019-10, 2019-11, and 2020-02 This standard replaces the incurred loss methodology for recognizing credit losses with a current expected credit losses model and applies to all financial assets, including trade receivables. Entities will adopt the standard using a modified-retrospective approach. January 1, 2020 We adopted this standard using the modified-retrospective approach in the first quarter of 2020. The adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to the Accounts Receivable paragraph above in Note 1 of the Consolidated Financial Statements for additional detail on our accounting policy. ASU 2017-04 "Intangibles - Goodwill and Other (Topic 350)" This standard simplifies the test for goodwill impairment by eliminating Step 2 of the impairment test. If the carrying amount of a reporting unit exceeds its fair value, an impairment loss shall be recognized in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. Entities will adopt the standard using a prospective approach. January 1, 2020 We adopted this standard using the prospective approach for our interim impairment test conducted in the first quarter of 2020. The goodwill impairment charge of $944 million recorded for the year ended December 31, 2020, was calculated in accordance with this standard. Please refer to Note 5 of the Consolidated Financial Statements for additional detail on this adoption. ASU 2016-02, "Leases (Topic 842)," as amended by ASU 2017-13, 2018-01, 2018-10, 2018-11, 2019-01, 2019-10, 2020-02 and 2020-05 The standard requires lessees to recognize a right-of-use asset and lease liability for all leases with terms of more than 12 months. The recognition and presentation of expenses will depend on classification as a finance or operating lease. Entities may elect to apply the provisions of the new leasing standard on January 1, 2019, without adjusting the comparative periods presented by recognizing a cumulative-effect adjustment to the opening balance of retained earnings. January 1, 2019 We adopted this standard using the optional transition method in the first quarter of 2019. Please refer to Note 7 of the Consolidated Financial Statements for ongoing disclosure requirements. Recently issued standards: ASU 2019-12 "Income Taxes (Topic 740)" This standard simplifies accounting for income taxes including such topics as intraperiod tax allocations, franchise taxes and separate company financial statements. January 1, 2021 We do not expect the adoption of this standard to have a material effect on our consolidated financial statements.

BUSINESS AND SUMMARY OF SIGNI_3

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (TABLE)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Property, Plant and Equipment	The range of useful lives for the major components of the Company’s plant and equipment is as follows: Buildings and leasehold improvements 15 – 40 years Machinery and equipment Furnaces 4 – 15 years Information systems 5 – 10 years Equipment 5 – 20 years Property, plant and equipment consist of the following (in millions): December 31, 2020 2019 Land $ 222 $ 221 Buildings and leasehold improvements 1,241 1,186 Machinery and equipment 5,155 4,978 Construction in progress 292 310 6,910 6,695 Accumulated depreciation (3,101) (2,840) Property, plant and equipment, net $ 3,809 $ 3,855

SEGMENT INFORMATION (TABLE)

SEGMENT INFORMATION (TABLE)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated	The following tables show a disaggregation of our net sales by segment and geographic region (in millions). Corporate eliminations (shown below) largely reflect intercompany sales from Composites to Roofing. External customer sales are attributed to geographic region based upon the location from which the product is sold to the external customer. Twelve Months Ended December 31, 2020 Reportable Segments Composites Insulation Roofing Eliminations Consolidated Disaggregation Categories U.S. residential $ 272 $ 949 $ 2,450 $ (204) $ 3,467 U.S. commercial and industrial 538 603 133 — 1,274 Total United States 810 1,552 2,583 (204) 4,741 Europe 524 609 14 (1) 1,146 Asia-Pacific 495 158 11 — 664 Rest of world 131 288 87 (2) 504 NET SALES $ 1,960 $ 2,607 $ 2,695 $ (207) $ 7,055 Twelve Months Ended December 31, 2019 Reportable Segments Composites Insulation Roofing Eliminations Consolidated Disaggregation Categories U.S. residential $ 269 $ 927 $ 2,375 $ (195) $ 3,376 U.S. commercial and industrial 614 643 143 — 1,400 Total United States 883 1,570 2,518 (195) 4,776 Europe 572 625 13 (1) 1,209 Asia-Pacific 475 176 13 — 664 Rest of world 129 297 90 (5) 511 NET SALES $ 2,059 $ 2,668 $ 2,634 $ (201) $ 7,160 Twelve Months Ended December 31, 2018 Reportable Segments Composites Insulation Roofing Eliminations Consolidated Disaggregation Categories U.S. residential $ 263 $ 990 $ 2,199 $ (177) $ 3,275 U.S. commercial and industrial 598 625 161 (12) 1,372 Total United States 861 1,615 2,360 (189) 4,647 Europe 590 605 14 — 1,209 Asia-Pacific 464 178 15 (1) 656 Rest of world 126 322 103 (6) 545 NET SALES $ 2,041 $ 2,720 $ 2,492 $ (196) $ 7,057
Schedule of Earnings before Interest and Taxes	The following table summarizes EBIT by segment (in millions): Twelve Months Ended December 31, 2020 2019 2018 Reportable Segments Composites $ 165 $ 247 $ 251 Insulation 250 230 290 Roofing 591 455 434 Total reportable segments 1,006 932 975 Restructuring costs (41) (28) (22) Gains on sale of certain precious metals 26 — — Goodwill impairment charge (944) — — Intangible assets impairment charge (43) — — Acquisition-related costs — — (16) Recognition of acquisition inventory fair value step-up — — (2) Pension settlement losses — (43) — Environmental liability charges — (4) — General corporate expense and other (128) (104) (114) Total Corporate, other and eliminations (1,130) (179) (154) EBIT $ (124) $ 753 $ 821
Reconciliation of Assets from Segment to Consolidated	The following table summarizes total assets by segment and property, plant and equipment by geographic region (in millions): December 31, TOTAL ASSETS 2020 2019 Reportable Segments Composites $ 2,426 $ 2,470 Insulation 3,937 4,975 Roofing 1,814 1,784 Total reportable segments 8,177 9,229 Cash and cash equivalents 717 172 Noncurrent deferred income taxes 28 46 Investments in affiliates 51 51 Assets held for sale 5 1 Corporate property, plant and equipment, other assets and eliminations 503 507 CONSOLIDATED TOTAL ASSETS $ 9,481 $ 10,006
Schedule of Property, Plant and Equipment by Geographical Areas	December 31, PROPERTY, PLANT AND EQUIPMENT BY GEOGRAPHIC REGION 2020 2019 United States $ 2,169 $ 2,204 Europe 777 762 Asia-Pacific 594 601 Rest of world 269 288 TOTAL PROPERTY, PLANT AND EQUIPMENT $ 3,809 $ 3,855
Schedule of Depreciation and Amortization by Segment	The following table summarizes the provision for depreciation and amortization by segment (in millions): Twelve Months Ended December 31, 2020 2019 2018 Reportable Segments Composites $ 159 $ 154 $ 147 Insulation 201 194 186 Roofing 59 54 51 Total reportable segments 419 402 384 General corporate depreciation and amortization (a) 74 55 49 CONSOLIDATED PROVISION FOR DEPRECIATION AND AMORTIZATION $ 493 $ 457 $ 433 (a) In 2020, 2019 and 2018, General corporate depreciation and amortization expense included $20 million, $9 million and $10 million, respectively, of accelerated depreciation related to restructuring actions further explained in Note 10 to the Consolidated Financial Statements.
Schedule of Additions to Property, Plant and Equipment by Segment	The following table summarizes additions to property, plant and equipment on an accrual basis by segment (in millions): Twelve Months Ended December 31, 2020 2019 2018 Reportable Segments Composites $ 105 $ 123 $ 154 Insulation 132 210 240 Roofing 46 56 91 Total reportable segments 283 389 485 General corporate additions 37 62 57 CONSOLIDATED ADDITIONS TO PROPERTY, PLANT AND EQUIPMENT $ 320 $ 451 $ 542

INVENTORIES (TABLE)

INVENTORIES (TABLE)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	Inventories consist of the following (in millions): December 31, 2020 2019 Finished goods $ 532 $ 715 Materials and supplies 323 318 Total inventories $ 855 $ 1,033

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (TABLE)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Assets and Liabilities at Fair Value	The following table presents the fair value of derivatives and hedging instruments and the respective location on the Consolidated Balance Sheets (in millions): Fair Value at Location December 31, 2020 December 31, 2019 Derivative assets designated as hedging instruments: Net investment hedges: Cross currency swaps Other current assets $ 5 $ 12 Cross currency swaps Other non-current assets $ — $ 1 Cash flow hedges: Natural gas forward swaps Other current assets $ 2 $ — Treasury interest rate lock Other non-current assets $ 4 $ — Derivative liabilities designated as hedging instruments: Net investment hedges: Cross-currency swaps Other liabilities $ 11 $ 4 Cash flow hedges: Natural gas forward swaps Total current liabilities $ — $ 3 Derivative assets not designated as hedging instruments: Foreign exchange forward contracts Other current assets $ 2 $ 9 Derivative liabilities not designated as hedging instruments: Foreign exchange forward contracts Total current liabilities $ 45 $ 1
Schedule of Fair Value Derivative Instruments Statements of Earnings Location	The following table presents the impact and respective location of derivative activities on the Consolidated Statements of Earnings (Loss) (in millions): Twelve Months Ended Location 2020 2019 2018 Derivative activity designated as hedging instruments: Natural gas cash flow hedges: Amount of loss/(gain) reclassified from AOCI (as defined below) into earnings (a) Cost of sales $ 5 $ 4 $ (2) Cross-currency swap net investment hedges: Amount of gain recognized in earnings on derivative amounts excluded from effectiveness testing Interest expense, net $ (8) $ (13) $ (12) Derivative activity not designated as hedging instruments: Foreign currency: Amount of (gain)/loss recognized in earnings (b) Other expenses, net $ 41 $ (35) $ (55) (a) Accumulated Other Comprehensive Earnings (Deficit) ("AOCI") The following table presents the impact of derivative activities on the Consolidated Statements of Comprehensive Earnings (Loss) (in millions): Amount of (Gain) Loss Recognized in Comprehensive Earnings (Loss) Twelve Months Ended December 31, Hedging Type Derivative Financial Instrument 2020 2019 Net investment hedge Cross-currency swaps $ (15) $ (18) Cash flow hedge Natural gas forward swaps $ (5) $ 2 Cash flow hedge Treasury interest rate lock $ (4) $ —

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLE ASSETS (TABLE)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the net carrying amount of goodwill by segment are as follows (in millions): Composites Insulation Roofing Total Balance at December 31, 2019 $ 57 $ 1,479 $ 396 $ 1,932 Impairment charge — (944) — (944) Divestiture — (4) — (4) Foreign currency translation — 1 4 5 Balance at December 31, 2020 $ 57 $ 532 $ 400 $ 989
Schedule of Finite-Lived Intangible Assets	December 31, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Accumulated Net Trademarks and trade names $ 1,109 $ — $ 1,109 $ 1,139 $ — $ 1,139 Customer relationships 570 (200) 370 550 (167) 383 Technology 327 (172) 155 319 (152) 167 Other 36 (3) 33 67 (35) 32 Total other intangible assets $ 2,042 $ (375) $ 1,667 $ 2,075 $ (354) $ 1,721
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated amortization expense for intangible assets for the next five years is as follows (in millions): Period Amortization 2021 $ 49 2022 $ 47 2023 $ 43 2024 $ 40 2025 $ 40

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (TABLE)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	The range of useful lives for the major components of the Company’s plant and equipment is as follows: Buildings and leasehold improvements 15 – 40 years Machinery and equipment Furnaces 4 – 15 years Information systems 5 – 10 years Equipment 5 – 20 years Property, plant and equipment consist of the following (in millions): December 31, 2020 2019 Land $ 222 $ 221 Buildings and leasehold improvements 1,241 1,186 Machinery and equipment 5,155 4,978 Construction in progress 292 310 6,910 6,695 Accumulated depreciation (3,101) (2,840) Property, plant and equipment, net $ 3,809 $ 3,855

LEASES (TABLE)

LEASES (TABLE)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Lease-Related Assets and Liabilities	The table below presents the lease-related assets and liabilities recorded on the balance sheet (in millions): December 31, Leases Classification on Balance Sheet 2020 2019 Assets Operating lease assets Operating lease right-of-use assets $ 154 $ 203 Finance lease assets Other non-current assets 73 21 Total lease assets $ 227 $ 224 Liabilities Current Operating Total current liabilities $ 55 $ 66 Finance Total current liabilities 19 7 Non-Current Operating Non-current operating lease liabilities 99 138 Finance Long-term debt, net of current portion 59 19 Total lease liabilities $ 232 $ 230
Lease, Cost	The table below presents lease-related costs (in millions): Twelve Months Ended December 31, 2020 2019 Operating lease cost $ 71 $ 81 Finance lease cost Amortization $ 16 $ 5 Interest $ 3 $ 2 Short-term lease cost $ 11 $ 10 Variable lease cost $ 5 $ 6 For the year ended December 31, 2018, total rent expense accounted for under ASC 840 was $106 million.
Supplemental Information Related to Leases	Other Information The tables below present supplemental information related to leases: December 31, Weighted-average remaining lease term (years) 2020 2019 Operating leases 3.8 4.0 Finance leases 6.8 3.9 December 31, Weighted-average discount rate 2020 2019 Operating leases 3.29 % 3.30 % Finance leases 4.04 % 6.29 %
Finance Lease, Liability, Maturity	The table below reconciles the undiscounted cash flows for each of the first five years and the total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheet as of December 31, 2020 (in millions): Period Operating Leases Finance Leases 2021 $ 59 $ 22 2022 45 19 2023 28 14 2024 15 8 2025 8 5 2026 and beyond 13 21 Total minimum lease payments 168 89 Less: implied interest 14 11 Present value of future minimum lease payments 154 78 Less: current lease obligations 55 19 Long-term lease obligations $ 99 $ 59
Lessee, Operating Lease, Liability, Maturity	The table below reconciles the undiscounted cash flows for each of the first five years and the total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheet as of December 31, 2020 (in millions): Period Operating Leases Finance Leases 2021 $ 59 $ 22 2022 45 19 2023 28 14 2024 15 8 2025 8 5 2026 and beyond 13 21 Total minimum lease payments 168 89 Less: implied interest 14 11 Present value of future minimum lease payments 154 78 Less: current lease obligations 55 19 Long-term lease obligations $ 99 $ 59

TOTAL CURRENT LIABILITIES (TABL

TOTAL CURRENT LIABILITIES (TABLE)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Current liabilities consist of the following current portions of these liabilities (in millions): December 31, 2020 2019 Accounts payable $ 875 $ 815 Payroll, vacation pay and incentive compensation 197 172 Current operating lease liabilities 55 66 Other 313 276 Total $ 1,440 $ 1,329

WARRANTIES (TABLE)

WARRANTIES (TABLE)	12 Months Ended
	Dec. 31, 2020
Product Warranties Disclosures [Abstract]
Schedule of Product Warranty Liability	A reconciliation of the warranty liability is as follows (in millions): December 31, 2020 2019 Beginning balance $ 64 $ 60 Amounts accrued for current year 21 21 Settlements of warranty claims (13) (17) Ending balance $ 72 $ 64

RESTRUCTURING AND ACQUISITION_2

RESTRUCTURING AND ACQUISITION-RELATED COSTS (TABLE)	12 Months Ended
	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Costs	The following table presents the impact and respective location of total restructuring costs on the Consolidated Statements of Earnings (Loss), which are included in our Corporate, Other and Eliminations category (in millions): Twelve Months Ended December 31, Type of Cost Location 2020 2019 2018 Accelerated depreciation Cost of sales $ 20 $ 9 $ 10 Other exit costs Cost of sales 6 6 7 Severance Other expenses, net 13 13 4 Other exit costs/(gains) (a) Other expenses, net 2 (1) 1 Other exit costs Non-operating expense (income) — 1 — Total restructuring costs $ 41 $ 28 $ 22
Cost Reductions Actions 2014
Restructuring Cost and Reserve [Line Items]
Schedule of Restructuring Reserve by Type of Cost	The following table summarizes the status of the unpaid liabilities from the Company’s restructuring activities (in millions): 2020 Insulation Restructuring Actions 2020 Composites Restructuring Actions Insulation Network Optimization Restructuring Acquisition-Related Restructuring Balance at December 31, 2019 $ — $ — $ 5 $ 11 Restructuring costs 23 13 5 — Payments (4) (6) (8) (6) Accelerated depreciation and other non-cash items (17) (5) (2) 4 Balance at December 31, 2020 $ 2 $ 2 $ — $ 9 Cumulative charges incurred $ 23 $ 13 $ 29 $ 29

DEBT (TABLE)

DEBT (TABLE)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Details of the Company’s outstanding long-term debt, as well as the fair values, are as follows (in millions): December 31, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value 4.200% senior notes, net of discount and financing fees, due 2022 $ 184 106 % $ 183 104 % 4.200% senior notes, net of discount and financing fees, due 2024 396 111 % 395 106 % 3.400% senior notes, net of discount and financing fees, due 2026 397 111 % 396 101 % 3.950% senior notes, net of discount and financing fees, due 2029 445 115 % 445 104 % 3.875% senior notes, net of discount and financing fees, due 2030 297 115 % — — % 7.000% senior notes, net of discount and financing fees, due 2036 368 142 % 367 126 % 4.300% senior notes, net of discount and financing fees, due 2047 588 120 % 588 95 % 4.400% senior notes, net of discount and financing fees, due 2048 390 121 % 390 97 % Various finance leases, due through 2036 (a) 78 100 % 26 100 % Term loan borrowing, maturing in 2021 (a) — — % 200 100 % Other 2 n/a 3 n/a Total long-term debt 3,145 n/a 2,993 n/a Less – current portion (a) 19 100 % 7 100 % Long-term debt, net of current portion $ 3,126 n/a $ 2,986 n/a (a) The Company determined that the book value of the above noted long-term debt instruments approximates fair value.
Schedule of Line of Credit Facilities	The following table shows how the Company utilized its primary sources of liquidity (in millions): Balance at December 31, 2020 Senior Revolving Credit Facility Receivables Securitization Facility Facility size $ 800 $ 280 Collateral capacity limitation on availability n/a — Outstanding borrowings — — Outstanding letters of credit 4 1 Availability on facility $ 796 $ 279
Schedule of Maturities of Long-term Debt	The aggregate maturities for all outstanding long-term debt borrowings for each of the five years following December 31, 2020 and thereafter are presented in the table below (in millions). The maturities below are the aggregate par amounts of the outstanding senior notes and finance lease liabilities: Period Maturities 2021 $ 19 2022 201 2023 13 2024 407 2025 4 2026 and beyond 2,544 Total $ 3,188

PENSION PLANS (TABLE)

PENSION PLANS (TABLE)	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Changes in Projected Benefit Obligations	The following tables provide a reconciliation of the change in the projected benefit obligation, the change in plan assets and the net amount recognized in the Consolidated Balance Sheets (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 866 $ 475 $ 1,341 $ 891 $ 427 $ 1,318 Service cost 5 5 10 5 5 10 Interest cost 28 10 38 34 13 47 Actuarial loss 83 28 111 85 42 127 Currency loss — 18 18 — 13 13 Benefits paid (71) (16) (87) (45) (18) (63) Plan amendments — 3 3 — — — Settlements/curtailments (1) (4) (5) (104) (7) (111) Other — 4 4 — — — Benefit obligation at end of period $ 910 $ 523 $ 1,433 $ 866 $ 475 $ 1,341
Schedule of Changes in Fair Value of Plan Assets	December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Plan Assets Fair value of assets at beginning of period $ 733 $ 386 $ 1,119 $ 727 $ 328 $ 1,055 Actual return on plan assets 80 37 117 130 50 180 Currency gain — 14 14 — 11 11 Company contributions 101 21 122 25 21 46 Benefits paid (71) (16) (87) (45) (18) (63) Settlements/curtailments (1) (4) (5) (104) (5) (109) Other — 3 3 — (1) (1) Fair value of assets at end of period $ 842 $ 441 $ 1,283 $ 733 $ 386 $ 1,119 Funded status $ (68) $ (82) $ (150) $ (133) $ (89) $ (222)
Schedule of Amounts Recognized in Balance Sheet	December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 12 $ 12 $ — $ 11 $ 11 Accrued pension cost – current — (2) (2) — (2) (2) Accrued pension cost – non-current (68) (92) (160) (133) (98) (231) Net amount recognized $ (68) $ (82) $ (150) $ (133) $ (89) $ (222)
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Amounts Recorded in AOCI Net actuarial loss $ (381) $ (109) $ (490) $ (345) $ (97) $ (442)
Schedule of Assumptions Used to Determine Benefit Obligations	The following table presents weighted average assumptions used to determine benefit obligations at the measurement dates: December 31, 2020 2019 United States Plans Discount rate 2.50 % 3.30 % Expected return on plan assets 4.75 % 6.50 % Cash balance interest crediting rate 0.79 % 2.66 % Non-United States Plans Discount rate 1.73 % 2.24 % Expected return on plan assets 4.08 % 4.66 % Rate of compensation increase 3.00 % 3.99 %
Schedule of Allocation of Plan Assets	The following table summarizes the fair values and applicable fair value hierarchy levels of United States pension plan assets (in millions): December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 53 $ — $ — $ 53 Fixed income and cash equivalents: Corporate bonds 31 288 — 319 Government debt — 68 — 68 Total United States plan assets subject to leveling $ 84 $ 356 $ — 440 Plan assets measured at NAV: Equities 193 Fixed income and cash equivalents 157 Absolute return strategies 52 Total United States plan assets $ 842 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 57 $ — $ — $ 57 International 55 — — 55 Fixed income and cash equivalents: Corporate bonds 28 214 — 242 Government debt — 85 — 85 Real estate investment trusts 22 — — 22 Total United States plan assets subject to leveling $ 162 $ 299 $ — 461 Plan assets measured at NAV: Equities 130 Real assets 62 Fixed income and cash equivalents 33 Absolute return strategies 47 Total United States plan assets $ 733 The following table summarizes the fair values and applicable fair value hierarchy levels of non-United States pension plan assets (in millions): December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 2 $ — $ 2 Cash and cash equivalents — 81 — 81 Fixed income — 9 — 9 Total non-United States plan assets subject to leveling $ — $ 92 $ — 92 Plan assets measured at NAV: Equities 86 Fixed income and cash equivalents 156 Absolute return strategies and other 107 Total non-United States plan assets $ 441 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents: Cash and cash equivalents — 65 — 65 Corporate bonds — 13 — 13 Total non-United States plan assets subject to leveling $ — $ 82 $ — 82 Plan assets measured at NAV: Equities 71 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 386
Pension Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	The following table presents information about the projected benefit obligation, accumulated benefit obligation (ABO) and plan assets of the Company’s pension plans (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with PBO in excess of fair value of plan assets: Projected benefit obligation $ 910 $ 364 $ 1,274 $ 866 $ 329 $ 1,195 Fair value of plan assets $ 842 $ 270 $ 1,112 $ 733 $ 229 $ 962 Plans with ABO in excess of fair value of plan assets: Accumulated benefit obligation $ 910 $ 330 $ 1,240 $ 866 $ 295 $ 1,161 Fair value of plan assets $ 842 $ 249 $ 1,091 $ 733 $ 205 $ 938
Schedule of Net Benefit Costs	The following table presents the components of net periodic pension cost (income) (in millions): Twelve Months Ended December 31, 2020 2019 2018 Service cost $ 10 $ 10 $ 12 Interest cost 38 47 47 Expected return on plan assets (62) (68) (73) Amortization of actuarial loss 15 15 15 Settlement/curtailment 1 44 — Net periodic pension cost $ 2 $ 48 $ 1
Schedule of Assumptions Used to Determine Net Benefit Cost	The following table presents weighted-average assumptions used to determine net periodic pension costs for the periods noted: Twelve Months Ended December 31, 2020 2019 2018 United States Plans Discount rate 3.30 % 4.25 % 3.55 % Expected return on plan assets 6.50 % 6.75 % 6.75 % Cash balance interest crediting rate 2.66 % 3.77 % 3.10 % Rate of compensation increase N/A (a) N/A (a) N/A (a) Non-United States Plans Discount rate 2.24 % 3.04 % 2.88 % Expected return on plan assets 4.66 % 4.91 % 5.22 % Rate of compensation increase 3.99 % 4.14 % 4.29 % (a) Not applicable due to changes in plan made on August 1, 2009 that were effective beginning January 1, 2010.
Schedule of Expected Benefit Payments	The following table shows estimated future benefit payments from the Company’s pension plans (in millions): Year Estimated Benefit Payments 2021 $ 82 2022 $ 78 2023 $ 78 2024 $ 79 2025 $ 76 2026-2030 $ 376
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Allocation of Plan Assets	December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities: Domestic $ 53 $ — $ — $ 53 Fixed income and cash equivalents: Corporate bonds 31 288 — 319 Government debt — 68 — 68 Total United States plan assets subject to leveling $ 84 $ 356 $ — 440 Plan assets measured at NAV: Equities 193 Fixed income and cash equivalents 157 Absolute return strategies 52 Total United States plan assets $ 842
Foreign Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Allocation of Plan Assets	December 31, 2020 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 2 $ — $ 2 Cash and cash equivalents — 81 — 81 Fixed income — 9 — 9 Total non-United States plan assets subject to leveling $ — $ 92 $ — 92 Plan assets measured at NAV: Equities 86 Fixed income and cash equivalents 156 Absolute return strategies and other 107 Total non-United States plan assets $ 441 December 31, 2019 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents: Cash and cash equivalents — 65 — 65 Corporate bonds — 13 — 13 Total non-United States plan assets subject to leveling $ — $ 82 $ — 82 Plan assets measured at NAV: Equities 71 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 386

POSTEMPLOYMENT AND POSTRETIRE_2

POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS (TABLE)	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Changes in Projected Benefit Obligations	The following tables provide a reconciliation of the change in the projected benefit obligation, the change in plan assets and the net amount recognized in the Consolidated Balance Sheets (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 866 $ 475 $ 1,341 $ 891 $ 427 $ 1,318 Service cost 5 5 10 5 5 10 Interest cost 28 10 38 34 13 47 Actuarial loss 83 28 111 85 42 127 Currency loss — 18 18 — 13 13 Benefits paid (71) (16) (87) (45) (18) (63) Plan amendments — 3 3 — — — Settlements/curtailments (1) (4) (5) (104) (7) (111) Other — 4 4 — — — Benefit obligation at end of period $ 910 $ 523 $ 1,433 $ 866 $ 475 $ 1,341
Schedule of Amounts Recognized in Balance Sheet	December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 12 $ 12 $ — $ 11 $ 11 Accrued pension cost – current — (2) (2) — (2) (2) Accrued pension cost – non-current (68) (92) (160) (133) (98) (231) Net amount recognized $ (68) $ (82) $ (150) $ (133) $ (89) $ (222)
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Amounts Recorded in AOCI Net actuarial loss $ (381) $ (109) $ (490) $ (345) $ (97) $ (442)
Schedule of Accumulated Postretirement Benefit Obligation and Plan Assets	The following table presents information about the accumulated postretirement benefit obligation (APBO) and plan assets of the Company's postretirement benefit plans (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with APBO in excess of fair value of plan assets: Accumulated postretirement benefit obligation $ 163 $ 14 $ 177 $ 169 $ 14 $ 183 Fair value of plan assets $ — $ — $ — $ — $ — $ —
Schedule of Assumptions Used to Determine Benefit Obligations	The following table presents weighted average assumptions used to determine benefit obligations at the measurement dates: December 31, 2020 2019 United States Plans Discount rate 2.50 % 3.30 % Expected return on plan assets 4.75 % 6.50 % Cash balance interest crediting rate 0.79 % 2.66 % Non-United States Plans Discount rate 1.73 % 2.24 % Expected return on plan assets 4.08 % 4.66 % Rate of compensation increase 3.00 % 3.99 %
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Changes in Projected Benefit Obligations	The following table provides a reconciliation of the change in the projected benefit obligation and the net amount recognized in the Consolidated Balance Sheets for the years ended December 31, 2020 and 2019 (in millions): December 31, 2020 December 31, 2019 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 169 $ 14 $ 183 $ 183 $ 12 $ 195 Service cost 1 — 1 1 — 1 Interest cost 5 1 6 7 1 8 Actuarial loss/(gain) — 1 1 (7) 2 (5) Currency gain — (1) (1) — — — Plan amendments — — — (1) — (1) Benefits paid (12) (1) (13) (14) (1) (15) Benefit obligation at end of period $ 163 $ 14 $ 177 $ 169 $ 14 $ 183 Funded status $ (163) $ (14) $ (177) $ (169) $ (14) $ (183)
Schedule of Amounts Recognized in Balance Sheet	Amounts Recognized in the Consolidated Balance Sheets Accrued benefit obligation – current $ (13) $ (1) $ (14) $ (15) $ (1) $ (16) Accrued benefit obligation – non-current (150) (13) (163) (154) (13) $ (167) Net amount recognized $ (163) $ (14) $ (177) $ (169) $ (14) $ (183)
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Amounts Recorded in AOCI Net actuarial gain $ 41 $ 2 $ 43 $ 48 $ 3 $ 51 Net prior service credit 2 — 2 6 — 6 Net amount recognized $ 43 $ 2 $ 45 $ 54 $ 3 $ 57
Schedule of Assumptions Used to Determine Benefit Obligations	The following table presents the discount rates used to determine the benefit obligations: December 31, 2020 2019 United States plans 2.25 % 3.10 % Non-United States plans 3.04 % 3.84 %
Schedule of Net Benefit Costs	The following table presents the components of net periodic postretirement benefit cost (income) (in millions): Twelve Months Ended December 31, 2020 2019 2018 Service cost $ 1 $ 1 $ 1 Interest cost 6 8 8 Amortization of prior service credit (4) (4) (4) Amortization of actuarial gain (8) (8) (6) Net periodic postretirement benefit income $ (5) $ (3) $ (1)
Schedule of Assumptions Used to Determine Net Benefit Cost	The following table presents the discount rates used to determine net periodic postretirement benefit cost: Twelve Months Ended December 31, 2020 2019 2018 United States plans 3.10 % 4.15 % 3.45 % Non-United States plans 3.84 % 4.59 % 4.56 %
Schedule of Health Care Cost Trend Rates	The following table presents health care cost trend rates used to determine net periodic postretirement benefit cost, as well as information regarding the ultimate rate and the year in which the ultimate rate is reached: Twelve Months Ended December 31, 2020 2019 2018 United States plans: Initial rate at end of year 8.20 % 6.50 % 6.75 % Ultimate rate 4.50 % 5.00 % 5.00 % Year in which ultimate rate is reached 2029 2026 2026 Non-United States plans: Initial rate at end of year 4.10 % 5.45 % 5.40 % Ultimate rate 3.90 % 5.45 % 5.40 % Year in which ultimate rate is reached 2040 2019 2019
Schedule of Expected Benefit Payments	The following table shows estimated future benefit payments from the Company’s postretirement benefit plans (in millions): Year Estimated Benefit Payments 2021 $ 14 2022 $ 14 2023 $ 13 2024 $ 13 2025 $ 12 2026-2030 $ 55

STOCK COMPENSATION (TABLE)

STOCK COMPENSATION (TABLE)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Disclosure of Share-based Compensation Expense	Stock-based compensation expense included in Marketing and administrative expenses in the accompanying Consolidated Statements of Earnings (Loss) is as follows (in millions): Twelve Months Ended December 31, 2020 2019 2018 Total stock-based compensation expense $ 41 $ 39 $ 47 Income tax benefit recognized on stock-based compensation expense $ 14 $ 7 $ 24
Schedule of Share-based Compensation, Stock Options, Activity	The following table summarizes the Company’s stock option activity in 2020: Weighted-Average Number of Options Exercise Price Remaining Intrinsic Value (in millions) Outstanding, December 31, 2019 414,800 $ 37.79 3.06 $ 11 Exercised (53,025) 37.90 Outstanding, December 31, 2020 361,775 $ 37.77 1.50 $ 14 Exercisable, December 31, 2020 361,775 $ 37.77 1.50 $ 14
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable	The total intrinsic value of stock options exercised and the resulting tax benefits received were as follows (in millions): Twelve Months Ended December 31, 2020 2019 2018 Cash received upon exercise of stock option awards $ 2 $ 2 $ 1 Income tax benefit received for stock option awards exercised $ — $ — $ —
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The following table shows a summary of the Company’s RSU plans: Number of Weighted- Balance at January 1, 2020 1,515,706 $ 51.70 Granted 513,111 63.96 Vested (515,247) 51.50 Forfeited (94,116) 67.09 Balance at December 31, 2020 1,419,454 $ 54.99
Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest	The following table shows a summary of the Company's PSU plans: Number of Weighted- Average Grant Date Fair Value Balance as of January 1, 2020 312,725 $ 69.23 Granted 169,539 65.29 Vested (98,842) 95.43 Forfeited (60,061) 74.09 Balance as of December 31, 2020 323,361 $ 69.20
Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity	The following table shows a summary of employee purchase activity under the ESPP: Twelve Months Ended December 31, 2020 2019 2018 Total shares purchased by employees 366,442 393,230 295,407 Average purchase price $ 45.17 $ 41.33 $ 48.93

CHANGES IN ACCUMULATED OTHER _2

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT (TABLE)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in accumulated other comprehensive income (deficit) (in millions): Twelve Months Ended December 31, 2020 2019 Currency Translation Adjustment Beginning balance $ (282) $ (306) Net investment hedge amounts classified into AOCI, net of tax 11 13 Gain on foreign currency translation 51 11 Other comprehensive income, net of tax 62 24 Ending balance $ (220) $ (282) Pension and Other Postretirement Adjustment Beginning balance $ (326) $ (350) Amounts reclassified from AOCI to net earnings, net of tax (a) 3 35 Amounts classified into AOCI, net of tax (49) (11) Other comprehensive (loss)/income, net of tax (46) 24 Ending balance $ (372) $ (326) Hedging Adjustment Beginning balance $ (2) $ — Amounts reclassified from AOCI to net earnings, net of tax (b) 4 3 Amounts classified into AOCI, net of tax 2 (5) Other comprehensive income/(loss), net of tax 6 (2) Ending balance $ 4 $ (2) Total AOCI ending balance $ (588) $ (610) (a) These AOCI components are included in the computation of total Pension and Other Postretirement cost and are recorded in Non-operating expense (income). See Notes 12 and 13 for additional information. (b) Amounts reclassified from (loss)/gain on cash flow hedges are reclassified from AOCI to income when the hedged item affects earnings and is recognized in Cost of sales or Interest expense, net depending on the hedged item. See Note 4 for additional information.

EARNINGS PER SHARE (TABLE)

EARNINGS PER SHARE (TABLE)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table is a reconciliation of weighted-average shares for calculating basic and diluted earnings (loss) per-share (in millions, except per share amounts): Twelve Months Ended December 31, 2020 2019 2018 Net earnings (loss) attributable to Owens Corning $ (383) $ 405 $ 545 Weighted-average number of shares outstanding used for basic earnings (loss) per share 108.6 109.2 110.4 Non-vested restricted and performance shares — 0.7 0.8 Options to purchase common stock — 0.2 0.2 Weighted-average number of shares outstanding and common equivalent shares used for diluted earnings (loss) per share 108.6 110.1 111.4 Earnings (loss) per common share attributable to Owens Corning common stockholders: Basic $ (3.53) $ 3.71 $ 4.94 Diluted $ (3.53) $ 3.68 $ 4.89

INCOME TAXES (TABLE)

INCOME TAXES (TABLE)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The following table summarizes our Earnings (loss) before taxes and Income tax expense (in millions): Twelve Months Ended December 31, 2020 2019 2018 Earnings before taxes: United States $ 8 $ 315 $ 411 Foreign (264) 275 293 Total $ (256) $ 590 $ 704
Schedule of Components of Income Tax Expense (Benefit), By Jurisdiction	Income tax expense: Current United States $ 4 $ (4) $ (10) State and local 16 11 6 Foreign 30 60 19 Total current 50 67 15 Deferred United States 64 112 114 State and local (1) 11 12 Foreign 16 (4) 15 Total deferred 79 119 141 Total income tax expense $ 129 $ 186 $ 156
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation between the United States federal statutory rate and the Company’s effective income tax rate from continuing operations is: Twelve Months Ended December 31, 2020 2019 2018 United States federal statutory rate 21 % 21 % 21 % State and local income taxes, net of federal tax benefit (9) 3 2 U.S. tax expense on foreign earnings (5) 1 2 Legislative tax rate changes 7 2 — Foreign tax credits 2 — — Valuation allowance (15) 3 2 Intercompany restructuring - intellectual property transfer 14 — — Goodwill impairment charge (75) — — Uncertain tax positions and settlements 2 — (5) Excess tax benefits related to stock compensation 2 — (2) Other, net 6 1 2 Effective tax rate (50) % 31 % 22 %
Schedule of Deferred Tax Assets and Liabilities	The cumulative temporary differences giving rise to the deferred tax assets and liabilities are as follows (in millions): December 31, 2020 December 31, 2019 Deferred Deferred Deferred Deferred Other employee benefits $ 71 $ — $ 76 $ — Pension plans 41 — 54 — Operating loss and tax credit carryforwards 170 — 195 — Depreciation — 259 — 247 Leases - Right of Use Assets — 33 — 49 Leases - Liability 33 — 49 — Amortization — 333 — 388 Foreign tax credits 49 — 97 — State and local taxes — — 3 — Other 90 — 76 — Subtotal 454 625 550 684 Valuation allowances (133) — (92) — Total deferred taxes $ 321 $ 625 $ 458 $ 684
Summary of Operating Loss and Tax Credit Carryforwards	The following table summarizes the amount and expiration dates of our deferred tax assets related to operating loss and credit carryforwards at December 31, 2020 (in millions): Expiration Amounts U.S. federal loss carryforwards 2036 $ 23 U.S. state loss carryforwards (a) 2021 – 2034 37 Foreign loss and tax credit carryforwards Indefinite 41 Foreign loss and tax credit carryforwards (a) 2021 – 2039 66 Other U.S. federal and state tax credits 2028 – 2034 3 Total operating loss and tax credit carryforwards $ 170 U.S foreign tax credits 2027 $ 49 (a) As of December 31, 2020, $12 million of U.S. state and $7 million of foreign deferred tax assets related to loss carryforwards that are set to expire over the next three years.
Summary of Income Tax Contingencies	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in millions): Twelve Months Ended December 31, 2020 2019 2018 Balance at beginning of period $ 79 $ 84 $ 90 Tax positions related to the current year Gross additions — — 6 Tax positions related to prior years Gross additions 2 1 36 Gross reductions (1) — (37) Settlements (1) (1) (5) Expiration of statute of limitations (3) (5) (4) Impact of currency changes — — (2) Balance at end of period $ 76 $ 79 $ 84

BUSINESS AND SUMMARY OF SIGNI_4

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (DETAIL) $ / shares in Units, $ in Millions	Feb. 04, 2021$ / shares	Dec. 31, 2020USD ($)segment$ / shares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)$ / shares
Property Plant And Equipment [Line Items]
Number of reportable segments | segment		3
Dividend (dollars per share) | $ / shares		$ 0.98	$ 0.90	$ 0.85
Revenue, remaining performance obligation		$ 4
Contract with customer, liability			$ 60
Marketing and advertising expense		98	117	$ 120
Restricted cash and cash equivalents		7
Investments in affiliates		$ 51	51
Precious metals depletion, percentage		3.00%
Foreign currency transaction gain (loss)		$ 6	$ 12	$ 7
Subsequent Event
Property Plant And Equipment [Line Items]
Dividend (dollars per share) | $ / shares	$ 0.26
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2036-01-01 | Minimum
Property Plant And Equipment [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period		16 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2040-01-01 | Maximum
Property Plant And Equipment [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period		20 years

BUSINESS AND SUMMARY OF SIGNI_5

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (PROPERTY, PLANT AND EQUIPMENT USEFUL LIFE) (DETAIL)	12 Months Ended
	Dec. 31, 2020
Building and Building Improvements | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	15 years
Building and Building Improvements | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	40 years
Furnaces | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	4 years
Furnaces | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	15 years
Technology Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	5 years
Technology Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	10 years
Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	5 years
Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment estimated useful lives	20 years

SEGMENT INFORMATION - Narrative

SEGMENT INFORMATION - Narrative (DETAIL)	12 Months Ended
	Dec. 31, 2020segment
Segment Reporting [Abstract]
Number of reportable segments	3

SEGMENT INFORMATION - Net Sales

SEGMENT INFORMATION - Net Sales by Reportable Segments (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 7,055	$ 7,160	$ 7,057
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(207)	(201)	(196)
United States
Disaggregation of Revenue [Line Items]
Net sales	4,741	4,776	4,647
United States | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(204)	(195)	(189)
Europe
Disaggregation of Revenue [Line Items]
Net sales	1,146	1,209	1,209
Europe | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(1)	(1)	0
Asia Pacific
Disaggregation of Revenue [Line Items]
Net sales	664	664	656
Asia Pacific | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	0	0	(1)
Rest of World
Disaggregation of Revenue [Line Items]
Net sales	504	511	545
Rest of World | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(2)	(5)	(6)
Composites
Disaggregation of Revenue [Line Items]
Net sales	1,960	2,059	2,041
Composites | United States
Disaggregation of Revenue [Line Items]
Net sales	810	883	861
Composites | Europe
Disaggregation of Revenue [Line Items]
Net sales	524	572	590
Composites | Asia Pacific
Disaggregation of Revenue [Line Items]
Net sales	495	475	464
Composites | Rest of World
Disaggregation of Revenue [Line Items]
Net sales	131	129	126
Insulation
Disaggregation of Revenue [Line Items]
Net sales	2,607	2,668	2,720
Insulation | United States
Disaggregation of Revenue [Line Items]
Net sales	1,552	1,570	1,615
Insulation | Europe
Disaggregation of Revenue [Line Items]
Net sales	609	625	605
Insulation | Asia Pacific
Disaggregation of Revenue [Line Items]
Net sales	158	176	178
Insulation | Rest of World
Disaggregation of Revenue [Line Items]
Net sales	288	297	322
Roofing
Disaggregation of Revenue [Line Items]
Net sales	2,695	2,634	2,492
Roofing | United States
Disaggregation of Revenue [Line Items]
Net sales	2,583	2,518	2,360
Roofing | Europe
Disaggregation of Revenue [Line Items]
Net sales	14	13	14
Roofing | Asia Pacific
Disaggregation of Revenue [Line Items]
Net sales	11	13	15
Roofing | Rest of World
Disaggregation of Revenue [Line Items]
Net sales	87	90	103
Residential | United States
Disaggregation of Revenue [Line Items]
Net sales	3,467	3,376	3,275
Residential | United States | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(204)	(195)	(177)
Residential | Composites | United States
Disaggregation of Revenue [Line Items]
Net sales	272	269	263
Residential | Insulation | United States
Disaggregation of Revenue [Line Items]
Net sales	949	927	990
Residential | Roofing | United States
Disaggregation of Revenue [Line Items]
Net sales	2,450	2,375	2,199
Commercial and Industrial Sector | United States
Disaggregation of Revenue [Line Items]
Net sales	1,274	1,400	1,372
Commercial and Industrial Sector | United States | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net sales	0	0	(12)
Commercial and Industrial Sector | Composites | United States
Disaggregation of Revenue [Line Items]
Net sales	538	614	598
Commercial and Industrial Sector | Insulation | United States
Disaggregation of Revenue [Line Items]
Net sales	603	643	625
Commercial and Industrial Sector | Roofing | United States
Disaggregation of Revenue [Line Items]
Net sales	$ 133	$ 143	$ 161

SEGMENT INFORMATION - EBIT by S

SEGMENT INFORMATION - EBIT by Segment (DETAIL) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Restructuring costs		$ (41)	$ (28)	$ (22)
Gains on sale of certain precious metals		26	0	0
Goodwill impairment charge	$ (944)	(944)	0	0
Intangible assets impairment charge		(43)	0	0
Acquisition-related costs		0	0	(16)
Recognition of InterWrap inventory fair value step-up		0	0	(2)
Environmental liability charges		0	(4)	0
General corporate expense and other		(128)	(104)	(114)
Total Corporate, other and eliminations		(124)	753	821
Composites
Segment Reporting Information [Line Items]
Goodwill impairment charge		0
Total Corporate, other and eliminations		165	247	251
Insulation
Segment Reporting Information [Line Items]
Goodwill impairment charge		(944)
Total Corporate, other and eliminations		250	230	290
Roofing
Segment Reporting Information [Line Items]
Goodwill impairment charge		0
Total Corporate, other and eliminations		591	455	434
Total Segments
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations		1,006	932	975
Corporate Eliminations
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations		(1,130)	(179)	(154)
Other Expense
Segment Reporting Information [Line Items]
Restructuring costs		(6)
Pension Plan
Segment Reporting Information [Line Items]
Pension settlement losses		(1)	(44)	0
Foreign Plan | Pension Plan
Segment Reporting Information [Line Items]
Pension settlement losses		$ 0	$ (43)	$ 0

SEGMENT INFORMATION - Total Ass

SEGMENT INFORMATION - Total Assets and Property, Plant and Equipment by Geographic Region (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total Assets	$ 9,481	$ 10,006
Cash and cash equivalents	717	172
Noncurrent deferred income taxes	28	46
Investments in affiliates	51	51
Assets held for sale	5	1
Corporate property, plant and equipment, net	503	507
Property, plant and equipment, net	3,809	3,855
Composites
Segment Reporting Information [Line Items]
Total Assets	2,426	2,470
Insulation
Segment Reporting Information [Line Items]
Total Assets	3,937	4,975
Roofing
Segment Reporting Information [Line Items]
Total Assets	1,814	1,784
Total Segments
Segment Reporting Information [Line Items]
Total Assets	8,177	9,229
United States
Segment Reporting Information [Line Items]
Property, plant and equipment, net	2,169	2,204
Europe
Segment Reporting Information [Line Items]
Property, plant and equipment, net	777	762
Asia Pacific
Segment Reporting Information [Line Items]
Property, plant and equipment, net	594	601
Other Geographical
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 269	$ 288

SEGMENT INFORMATION - Provision

SEGMENT INFORMATION - Provision For Depreciation and Amortization (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 493	$ 457	$ 433
Charges related to cost reduction actions	41	28	22
Composites
Segment Reporting Information [Line Items]
Depreciation and amortization	159	154	147
Insulation
Segment Reporting Information [Line Items]
Depreciation and amortization	201	194	186
Roofing
Segment Reporting Information [Line Items]
Depreciation and amortization	59	54	51
Total Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	419	402	384
General Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization	74	55	49
Accelerated Depreciation | Cost of Sales
Segment Reporting Information [Line Items]
Charges related to cost reduction actions	$ 20	$ 9	$ 10

SEGMENT INFORMATION - Additions

SEGMENT INFORMATION - Additions to Property, Plant and Equipment (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Property, plant and equipment, additions	$ 320	$ 451	$ 542
Composites
Segment Reporting Information [Line Items]
Property, plant and equipment, additions	105	123	154
Insulation
Segment Reporting Information [Line Items]
Property, plant and equipment, additions	132	210	240
Roofing
Segment Reporting Information [Line Items]
Property, plant and equipment, additions	46	56	91
Total Segments
Segment Reporting Information [Line Items]
Property, plant and equipment, additions	283	389	485
General Corporate
Segment Reporting Information [Line Items]
Property, plant and equipment, additions	$ 37	$ 62	$ 57

INVENTORIES (DETAIL)

INVENTORIES (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Finished goods	$ 532	$ 715
Materials and supplies	323	318
Total inventories	$ 855	$ 1,033

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (BALANCE SHEET) (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Other current assets | Designated as Hedging Instrument | Net Investment Hedging | Cross Currency Interest Rate Contract
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net	$ 5	$ 12
Other current assets | Designated as Hedging Instrument | Cash Flow Hedging | Treasury interest rate lock
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net	4	0
Other current assets | Designated as Hedging Instrument | Cash Flow Hedging | Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net	2	0
Other current assets | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Net	2	9
Other non-current assets | Designated as Hedging Instrument | Net Investment Hedging | Cross Currency Interest Rate Contract
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net	0	1
Other liabilities | Designated as Hedging Instrument | Net Investment Hedging | Cross Currency Interest Rate Contract
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Net	11	4
Current liabilities | Designated as Hedging Instrument | Cash Flow Hedging | Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Net	0	3
Current liabilities | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Net	$ 45	$ 1

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS (INCOME STMT) (DETAIL) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cost of Sales | Designated as Hedging Instrument | Energy Related Derivative
Derivative Instruments Gain Loss [Line Items]
Amount of loss/(gain) reclassified from AOCI (as defined below) into earnings (a)		$ (5)	$ (4)	$ 2
Other Expense | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative Instruments Gain Loss [Line Items]
Amount of loss recognized in earnings (ineffective portion)		(41)	35	55
Interest Expense | Designated as Hedging Instrument | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Amount of gain recognized in earnings on derivative amounts excluded from effectiveness testing		(8)	$ (13)	$ (12)
Net Investment Hedging | Cross Currency Interest Rate Contract
Derivative Instruments Gain Loss [Line Items]
Amount of loss recognized in earnings (ineffective portion)	$ 15	18
Cash Flow Hedging | Energy Related Derivative
Derivative Instruments Gain Loss [Line Items]
Amount of loss recognized in earnings (ineffective portion)	5	(2)
Cash Flow Hedging | Treasury interest rate lock
Derivative Instruments Gain Loss [Line Items]
Amount of loss recognized in earnings (ineffective portion)	$ 4	$ 0

DERIVATIVE FINANCIAL INSTRUME_5

DERIVATIVE FINANCIAL INSTRUMENTS NARRATIVE (DETAIL) MMBTU in Millions, $ in Millions	Dec. 31, 2020USD ($)MMBTU
Derivative [Line Items]
Notional amount, energy measure | MMBTU	2
Interest Rate Lock Commitments
Derivative [Line Items]
Notional amount	$ 175
Fixed interest rate	0.994%
Dollars | Cross Currency Interest Rate Contract
Derivative [Line Items]
Notional amount	$ 218
Euros | Foreign Exchange Forward
Derivative [Line Items]
Notional amount	198
United States | Foreign Exchange Forward
Derivative [Line Items]
Notional amount	$ 729

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLE ASSETS - Narrative (DETAIL) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Finite-Lived Intangible Assets [Line Items]
Non-cash impairment charge	$ 944
Impaired goodwill carrying amount	173
Other
Finite-Lived Intangible Assets [Line Items]
Non-cash impairment charge	43
Insulation
Finite-Lived Intangible Assets [Line Items]
Impaired goodwill carrying amount	264
Insulation | Trade name
Finite-Lived Intangible Assets [Line Items]
Non-cash impairment charge	34
Insulation | Trademarks
Finite-Lived Intangible Assets [Line Items]
Non-cash impairment charge	$ 9

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLE ASSETS - ROLLFORWARD (DETAIL) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Beginning Balance		$ 1,932
Impairment charge	$ (944)	(944)	$ 0	$ 0
Divestiture		(4)
Foreign currency translation		5
Ending Balance	989	989	1,932
Composites
Goodwill [Roll Forward]
Beginning Balance		57
Impairment charge		0
Divestiture		0
Foreign currency translation		0
Ending Balance	57	57	57
Insulation
Goodwill [Roll Forward]
Beginning Balance		1,479
Impairment charge		(944)
Divestiture		(4)
Foreign currency translation		1
Ending Balance	532	532	1,479
Roofing
Goodwill [Roll Forward]
Beginning Balance		396
Impairment charge		0
Divestiture		0
Foreign currency translation		4
Ending Balance	$ 400	$ 400	$ 396

GOODWILL AND OTHER INTANGIBLE_5

GOODWILL AND OTHER INTANGIBLE ASSETS (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,042	$ 2,075
Accumulated Amortization	(375)	(354)
Net Carrying Amount	1,667	1,721
Goodwill	989	1,932
Trademarks
Intangible Assets [Line Items]
Gross Carrying Amount	1,109	1,139
Accumulated Amortization	0	0
Net Carrying Amount	1,109	1,139
Customer Relationships
Intangible Assets [Line Items]
Gross Carrying Amount	570	550
Accumulated Amortization	(200)	(167)
Net Carrying Amount	370	383
Technology
Intangible Assets [Line Items]
Gross Carrying Amount	327	319
Accumulated Amortization	(172)	(152)
Net Carrying Amount	155	167
Other
Intangible Assets [Line Items]
Gross Carrying Amount	36	67
Accumulated Amortization	(3)	(35)
Net Carrying Amount	$ 33	$ 32

GOODWILL AND OTHER INTANGIBLE_6

GOODWILL AND OTHER INTANGIBLE ASSETS (ESTIMATED AMORTIZATION EXPENSE) (DETAIL) $ in Millions	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 49
2021	47
2022	43
2023	40
2024	$ 40

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	$ 6,910	$ 6,695
Accumulated depreciation	(3,101)	(2,840)
Property, plant and equipment, net	$ 3,809	3,855
Precious metals percentage	10.00%
Depreciation	$ 429	403	$ 384
Accelerated depreciation related to cost reduction actions	20	9	$ 10
Land
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	222	221
Buildings and Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	1,241	1,186
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	5,155	4,978
Construction in Progress
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	$ 292	$ 310

LEASES - Balance Sheet Informat

LEASES - Balance Sheet Information Related to Leases (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 154	$ 203
Finance lease, right-of-use asset	73	21
Total lease assets	227	224
Operating lease, liability, current	55	66
Finance lease, liability, current	19	7
Non-current operating lease liabilities	99	138
Non-current finance leases	59	19
Total lease liabilities	$ 232	$ 230

LEASES - Lease Related Costs (D

LEASES - Lease Related Costs (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 71	$ 81
Finance lease cost
Amortization	16	5
Interest	3	2
Short-term lease cost	11	10
Variable lease cost	$ 5	$ 6

LEASES - Narrative (DETAIL)

LEASES - Narrative (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease rent expense			$ 106
Finance lease payments	$ 16	$ 5
Operating lease, payments	3	2
Right-of-use asset obtained in exchange for operating lease liability	36	47
Right-of-use asset obtained in exchange for finance lease liability	$ 69	$ 12

LEASES - Supplemental Informati

LEASES - Supplemental Information Related to Leases (DETAIL)	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease, weighted average remaining lease term	3 years 9 months 18 days	4 years
Finance lease, weighted average remaining lease term	6 years 9 months 18 days	3 years 10 months 24 days
Operating lease, weighted average discount rate, percent	3.29%	0.033%
Financing lease, weighted average discount rate, percent	4.04%	0.0629%

LEASES - Operating and Financin

LEASES - Operating and Financing Lease Liability Maturity (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2021	$ 59
2022	45
2023	28
2024	15
2025	8
2026 and beyond	13
Total minimum lease payments	168
Less: implied interest	14
Present value of future minimum lease payments	154
Less: current lease obligations	55
Long-term lease obligations	99	$ 138
Finance Lease, Liability, Payment, Due [Abstract]
2021	22
2022	19
2023	14
2024	8
2025	5
2026 and beyond	21
Total minimum lease payments	89
Less: implied interest	11
Present value of future minimum lease payments	78
Less: current lease obligations	19	7
Long-term lease obligations	$ 59	$ 19

TOTAL CURRENT LIABILITIES (DETA

TOTAL CURRENT LIABILITIES (DETAIL) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable	$ 875	$ 815
Payroll, vacation pay and incentive compensation	197	172
Current operating lease liabilities	55	66
Other	313	276
Accounts payable and accrued liabilities	$ 1,440	$ 1,329

WARRANTIES (DETAIL)

WARRANTIES (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement In Standard And Extended Product Warranty Increase Decrease [Roll Forward]
Product warranty accrual, beginning balance	$ 64	$ 60
Amounts accrued for current year	21	21
Settlements of warranty claims	(13)	(17)
Product warranty accrual, ending balance	$ 72	$ 64

RESTRUCTURING AND ACQUISITION_3

RESTRUCTURING AND ACQUISITION-RELATED COSTS (DETAIL) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		$ 41	$ 28	$ 22
Employee Severance
Restructuring Reserve Roll Forward
Ending Balance	$ 13	13
Non-current Severance
Restructuring Reserve Roll Forward
Ending Balance	3	3
Current Severance
Restructuring Reserve Roll Forward
Ending Balance	10	10
Cost of Sales | Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		20	9	10
Cost of Sales | Additional Exit Costs
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		6	6	7
Other Expense
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		6
Other Expense | Employee Severance
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		13	13	4
Other Expense | Additional Exit Costs
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		2	(1)	1
Non-Operating Expenses | Additional Exit Costs
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions		0	1	$ 0
Cost Reduction Actions 2020
Restructuring Reserve Roll Forward
Restructuring costs	13
Cost Reduction Actions 2020 | Employee Severance
Restructuring Reserve Roll Forward
Restructuring costs		5
Cost Reduction Actions 2020 | Accelerated Depreciation
Restructuring Reserve Roll Forward
Ending Balance	6	6
Cost Reduction Actions 2020 | Additional Exit Costs
Restructuring Reserve Roll Forward
Restructuring costs		2
2020 Insulation Restructuring Actions
Restructuring Reserve Roll Forward
Beginning Balance		0
Restructuring costs	23	23
Payments		(4)
Accelerated depreciation and other non-cash items		17
Ending Balance	2	2	0
Cumulative charges incurred	23	23
2020 Insulation Restructuring Actions | Employee Severance
Restructuring Reserve Roll Forward
Restructuring costs		6
2020 Insulation Restructuring Actions | Accelerated Depreciation
Restructuring Reserve Roll Forward
Ending Balance	14	14
2020 Insulation Restructuring Actions | Additional Exit Costs
Restructuring Reserve Roll Forward
Restructuring costs		3
2020 Composites Restructuring Actions
Restructuring Reserve Roll Forward
Beginning Balance		0
Restructuring costs		13
Payments		(6)
Accelerated depreciation and other non-cash items		5
Ending Balance	2	2	0
Cumulative charges incurred	13	13
Insulation Network Optimization Restructuring
Restructuring Reserve Roll Forward
Beginning Balance		5
Restructuring costs		5
Payments		(8)
Accelerated depreciation and other non-cash items		2
Ending Balance	0	0	5
Cumulative charges incurred	29	29
Paroc and Pittsburgh Corning
Restructuring Reserve Roll Forward
Beginning Balance		11
Restructuring costs		0
Payments		(6)
Accelerated depreciation and other non-cash items		4
Ending Balance	9	9	$ 11
Cumulative charges incurred	$ 29	$ 29

DEBT (SCHEDULE OF DEBT) (DETAIL

DEBT (SCHEDULE OF DEBT) (DETAIL) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt	$ 3,145,000,000	$ 2,993,000,000
Other	2,000,000	3,000,000
Less – current portion	19,000,000	7,000,000
Long-term debt, net of current portion	$ 3,126,000,000	$ 2,986,000,000
Notes payable, fair value	100.00%	100.00%
4.200% senior notes, net of discount and financing fees, due 2022
Debt Instrument [Line Items]
Long-term debt	$ 184,000,000	$ 183,000,000
Notes payable, fair value	106.00%	104.00%
4.200% senior notes, net of discount and financing fees, due 2024
Debt Instrument [Line Items]
Long-term debt	$ 396,000,000	$ 395,000,000
Notes payable, fair value	111.00%	106.00%
3.400% senior notes, net of discount and financing fees, due 2026
Debt Instrument [Line Items]
Long-term debt	$ 397,000,000	$ 396,000,000
Notes payable, fair value	111.00%	101.00%
3.950% senior notes, net of discount and financing fees, due 2029
Debt Instrument [Line Items]
Long-term debt	$ 445,000,000	$ 445,000,000
Notes payable, fair value	115.00%	104.00%
3.875% senior notes, net of discount and financing fees, due 2030
Debt Instrument [Line Items]
Long-term debt	$ 297,000,000	$ 0
Notes payable, fair value	115.00%	0.00%
7.000% senior notes, net of discount and financing fees, due 2036
Debt Instrument [Line Items]
Long-term debt	$ 368,000,000	$ 367,000,000
Notes payable, fair value	142.00%	126.00%
4.300% senior notes, net of discount and financing fees, due 2047
Debt Instrument [Line Items]
Long-term debt	$ 588,000,000	$ 588,000,000
Notes payable, fair value	120.00%	95.00%
4.400% senior notes, net of discount and financing fees, due 2048
Debt Instrument [Line Items]
Long-term debt	$ 390,000,000	$ 390,000,000
Notes payable, fair value	121.00%	97.00%
Various finance leases, due through 2032
Debt Instrument [Line Items]
Long-term debt	$ 78,000,000	$ 26,000,000
Notes payable, fair value	100.00%	100.00%
Term loan borrowing, maturing in 2021
Debt Instrument [Line Items]
Long-term debt	$ 0	$ 200,000,000
Notes payable, fair value	0.00%	100.00%

DEBT (DETAIL)

DEBT (DETAIL) - USD ($)	Aug. 12, 2019	Aug. 08, 2016	Nov. 12, 2014	Oct. 17, 2012	Mar. 31, 2020	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 12, 2020	Jan. 25, 2018	Oct. 27, 2017	Jun. 26, 2017	Oct. 31, 2006
Long-Term Debt [Line Items]
Loss on extinguishment of debt							$ 0	$ 32,000,000	$ 0
Other							2,000,000	3,000,000
Borrowing capacity under credit facility							800,000,000
Current maturities							19,000,000	7,000,000
Short-term Debt [Abstract]
Short-term debt							$ 1,000,000	$ 20,000,000
Term (in years)						1 year
Short term debt, weighted average interest rate							1.10%	7.80%
Long-term debt							$ 3,145,000,000	$ 2,993,000,000
Notes payable, fair value							100.00%	100.00%
Notes Payable, Fair Value Disclosure, Par Value							(100.00%)	(100.00%)
3.875% senior notes, net of discount and financing fees, due 2030
Long-Term Debt [Line Items]
Face amount										$ 300,000,000
Discount										$ 3,000,000
Short-term Debt [Abstract]
Long-term debt							$ 297,000,000	$ 0
Notes payable, fair value							115.00%	0.00%
Notes Payable, Fair Value Disclosure, Par Value							(115.00%)	0.00%
3.950% senior notes, net of discount and financing fees, due 2029
Long-Term Debt [Line Items]
Face amount	$ 450,000,000
Discount	5,000,000
Short-term Debt [Abstract]
Long-term debt							$ 445,000,000	$ 445,000,000
Notes payable, fair value							115.00%	104.00%
Notes Payable, Fair Value Disclosure, Par Value							(115.00%)	(104.00%)
7.000% senior notes, net of discount and financing fees, due 2036
Long-Term Debt [Line Items]
Fixed interest, percentage rate							7.00%	7.00%
Face amount														$ 550,000,000
Repayments	34,000,000						$ 140,000,000
Short-term Debt [Abstract]
Long-term debt							$ 368,000,000	$ 367,000,000
Notes payable, fair value							142.00%	126.00%
Notes Payable, Fair Value Disclosure, Par Value							(142.00%)	(126.00%)
Senior Note 2048
Long-Term Debt [Line Items]
Face amount											$ 400,000,000
Short-term Debt [Abstract]
Long-term debt							$ 390,000,000	$ 390,000,000
Notes payable, fair value							121.00%	97.00%
Notes Payable, Fair Value Disclosure, Par Value							(121.00%)	(97.00%)
4.300% senior notes, net of discount and financing fees, due 2047
Long-Term Debt [Line Items]
Fixed interest, percentage rate							4.30%
Face amount													$ 600,000,000
Short-term Debt [Abstract]
Long-term debt							$ 588,000,000	$ 588,000,000
Notes payable, fair value							120.00%	95.00%
Notes Payable, Fair Value Disclosure, Par Value							(120.00%)	(95.00%)
3.400% senior notes, net of discount and financing fees, due 2026
Long-Term Debt [Line Items]
Fixed interest, percentage rate							3.40%	3.40%
Face amount		$ 400,000,000
Short-term Debt [Abstract]
Long-term debt							$ 397,000,000	$ 396,000,000
Notes payable, fair value							111.00%	101.00%
Notes Payable, Fair Value Disclosure, Par Value							(111.00%)	(101.00%)
Senior Notes Due 2016
Long-Term Debt [Line Items]
Repayments		$ 158,000,000	$ 242,000,000	$ 250,000,000
4.200% senior notes, net of discount and financing fees, due 2024
Long-Term Debt [Line Items]
Fixed interest, percentage rate							4.20%	4.20%
Face amount			400,000,000
Short-term Debt [Abstract]
Long-term debt							$ 396,000,000	$ 395,000,000
Notes payable, fair value							111.00%	106.00%
Notes Payable, Fair Value Disclosure, Par Value							(111.00%)	(106.00%)
9.00% senior notes, net of discount and financing fees, due 2019
Long-Term Debt [Line Items]
Fixed interest, percentage rate								9.00%
Repayments			$ 105,000,000	100,000,000			$ 144,000,000
4.200% senior notes, net of discount and financing fees, due 2022
Long-Term Debt [Line Items]
Fixed interest, percentage rate							4.20%	4.20%
Face amount				$ 600,000,000
Repayments	$ 416,000,000
Short-term Debt [Abstract]
Long-term debt							$ 184,000,000	$ 183,000,000
Notes payable, fair value							106.00%	104.00%
Notes Payable, Fair Value Disclosure, Par Value							(106.00%)	(104.00%)
Term Loan Commitment Two
Long-Term Debt [Line Items]
Borrowing capacity under credit facility												$ 600,000,000
Senior Revolving Credit Facility B
Long-Term Debt [Line Items]
Proceeds from issuance of debt					$ 600,000,000
Borrowing capacity under credit facility							$ 800,000,000
Letter of Credit Under Receivables Purchase Agreement
Long-Term Debt [Line Items]
Borrowing capacity under credit facility							280,000,000
Current maturities							$ 280,000,000

DEBT (CREDIT FACILITY UTILIZATI

DEBT (CREDIT FACILITY UTILIZATION) (DETAIL) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Facility size	$ 800
Senior Revolving Credit Facility B
Debt Instrument [Line Items]
Facility size	800
Outstanding borrowings	0
Outstanding letters of credit	4
Availability on facility	796
Letter of Credit Under Receivables Purchase Agreement
Debt Instrument [Line Items]
Facility size	280
Collateral capacity limitation on availability	0
Outstanding borrowings	0
Outstanding letters of credit	1
Availability on facility	$ 279

DEBT (SCHEDULE OF DEBT MATURITI

DEBT (SCHEDULE OF DEBT MATURITIES) (DETAIL) $ in Millions	Dec. 31, 2020USD ($)
Maturities of Long-term Debt [Abstract]
2021	$ 19
2022	201
2023	13
2024	407
2025	4
2026 and beyond	2,544
Total	$ 3,188

PENSION PLANS (DETAIL)

PENSION PLANS (DETAIL) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)plan	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Defined Benefit Plan Disclosure [Line Items]
Non-operating expense (income)	$ (14)	$ 34	$ (14)
Defined Benefit Plans, Accumulated Other Comprehensive Income (Loss), After Tax [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations, Period	20 years
Defined Benefit Plan, Target Plan Asset Allocations Range Amount	25.00%
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2021				$ 14
2022				14
2023				13
2024				13
2025				12
2026-2030				55
Defined Contribution Plan [Abstract]
Defined contribution plans, number of plans | plan	2
Cost Recognized Related to Defined Benefit Plans	$ 48	48	48
Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	1,341	1,318
Service cost	10	10	12
Interest cost	38	47	47
Actuarial loss/(gain)	111	127
Currency gain	18	13
Benefits paid	(87)	(63)
Plan amendments	(3)	0
Defined Benefit Plan, Settlements / Curtailments	(5)	(111)
Other	4	0
Benefit Obligation at End of Period	1,433	1,341	1,318
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	1,119	1,055
Actual return on plan assets	117	180
Currency gain	14	11
Company contributions	122	46
Benefits paid	(87)	(63)
Settlements/curtailments	(5)	(109)
Other	3	(1)
Fair Value of Assets at End of Period	1,283	1,119	1,055
Funded status				(150)	$ (222)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Prepaid pension cost				12	11
Accrued pension cost – current				(2)	(2)
Accrued pension cost – non-current				(160)	(231)
Net amount recognized				(150)	(222)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial loss				(490)	(442)
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Projected Benefit Obligation				1,274	1,195
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Fair Value of Plan Assets				1,112	962
Defined Benefit Plan, Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract]
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Accumulated Benefit Obligation				1,240	1,161
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Fair Value of Plan Assets				1,091	938
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	10	10	12
Expected return on plan assets	(62)	(68)	(73)
Amortization of actuarial gain	15	15	15
Settlement/curtailment	1	44	0
Net periodic postretirement benefit income	2	48	1
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	1,119	1,119	1,055	1,283	$ 1,119
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2021				82
2022				78
2023				78
2024				79
2025				76
2026-2030				$ 376
United States
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	461
Fair Value of Assets at End of Period	440	461
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate				2.50%	3.30%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Return on Assets				4.75%	6.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate				0.79%	2.66%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	461	461		$ 440	$ 461
United States | Equities, Domestic
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	57
Fair Value of Assets at End of Period	53	57
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	57	57		53	57
United States | Equities, International
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	55
Fair Value of Assets at End of Period		55
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	55	55			55
United States | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	242
Fair Value of Assets at End of Period	319	242
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	242	242		319	242
United States | Government Debt
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	85
Fair Value of Assets at End of Period	68	85
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	85	85		68	85
United States | Real estate investment trusts
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	22
Fair Value of Assets at End of Period		22
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	22	22			22
United States | Fair Value, Inputs, Level 1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	162
Fair Value of Assets at End of Period	84	162
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	162	162		84	162
United States | Fair Value, Inputs, Level 1 | Equities, Domestic
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	57
Fair Value of Assets at End of Period	53	57
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	57	57		53	57
United States | Fair Value, Inputs, Level 1 | Equities, International
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	55
Fair Value of Assets at End of Period		55
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	55	55			55
United States | Fair Value, Inputs, Level 1 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	28
Fair Value of Assets at End of Period	31	28
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	28	28		31	28
United States | Fair Value, Inputs, Level 1 | Government Debt
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
United States | Fair Value, Inputs, Level 1 | Real estate investment trusts
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	22
Fair Value of Assets at End of Period		22
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	22	22			22
United States | Fair Value, Inputs, Level 2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	299
Fair Value of Assets at End of Period	356	299
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	299	299		356	299
United States | Fair Value, Inputs, Level 2 | Equities, Domestic
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
United States | Fair Value, Inputs, Level 2 | Equities, International
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period		0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0			0
United States | Fair Value, Inputs, Level 2 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	214
Fair Value of Assets at End of Period	288	214
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	214	214		288	214
United States | Fair Value, Inputs, Level 2 | Government Debt
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	85
Fair Value of Assets at End of Period	68	85
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	85	85		68	85
United States | Fair Value, Inputs, Level 2 | Real estate investment trusts
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period		0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0			0
United States | Fair Value, Inputs, Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
United States | Fair Value, Inputs, Level 3 | Equities, Domestic
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
United States | Fair Value, Inputs, Level 3 | Equities, International
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period		0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0			0
United States | Fair Value, Inputs, Level 3 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
United States | Fair Value, Inputs, Level 3 | Government Debt
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
United States | Fair Value, Inputs, Level 3 | Real estate investment trusts
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period		0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0			0
United States | NAV
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	733
Fair Value of Assets at End of Period	842	733
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	733	733		842	733
United States | NAV | Equities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	130
Fair Value of Assets at End of Period	193	130
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	130	130		193	130
United States | NAV | Real assets
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	62
Fair Value of Assets at End of Period		62
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	62	62			62
United States | NAV | Fixed income and cash equivalents
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	33
Fair Value of Assets at End of Period	157	33
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	33	33		157	33
United States | NAV | Absolute return strategies and other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	47
Fair Value of Assets at End of Period	52	47
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	47	47		52	47
United States | Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	866	891
Service cost	5	5
Interest cost	28	34
Actuarial loss/(gain)	83	85
Currency gain	0	0
Benefits paid	(71)	(45)
Plan amendments	0	0
Defined Benefit Plan, Settlements / Curtailments	(1)	(104)
Other	0	0
Benefit Obligation at End of Period	910	866	891
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	733	727
Actual return on plan assets	80	130
Currency gain	0	0
Company contributions	101	25
Benefits paid	(71)	(45)
Settlements/curtailments	(1)	(104)
Other	0	0
Fair Value of Assets at End of Period	842	733	$ 727
Funded status				(68)	(133)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Prepaid pension cost				0	0
Accrued pension cost – current				0	0
Accrued pension cost – non-current				(68)	(133)
Net amount recognized				(68)	(133)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial loss				(381)	(345)
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Projected Benefit Obligation				910	866
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Accumulated Benefit Obligation				842	733
Defined Benefit Plan, Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract]
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Accumulated Benefit Obligation				910	866
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Fair Value of Plan Assets				842	733
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 5	$ 5
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	3.30%	4.25%	3.55%
Expected return on plan assets	6.50%	6.75%	6.75%
Cash balance interest crediting rate	2.66%	3.77%	3.10%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	$ 733	$ 733	$ 727	$ 842	$ 733
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Percentage of Assets Invested in Equity	28.50%
Percentage of Assets Invested in Intermediate and Long-term Fixed income Securities	65.50%
Percentage of Assets Invested in Absolute Return Securities	6.00%
Defined Contribution Plan [Abstract]
Company Match Regardless of Employee Contribution				2.00%
Foreign Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	$ 82
Fair Value of Assets at End of Period	92	82
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate				1.73%	2.24%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Return on Assets				4.08%	4.66%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase				3.00%	3.99%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	82	82		$ 92	$ 82
Defined Contribution Plan [Abstract]
Expected contributions by employer				25
Foreign Plan | Equities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	4
Fair Value of Assets at End of Period	2	4
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	4	4		2	4
Foreign Plan | Cash and cash equivalents
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	65
Fair Value of Assets at End of Period	81	65
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	65	65		81	65
Foreign Plan | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	13
Fair Value of Assets at End of Period	9	13
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	13	13		9	13
Foreign Plan | Fair Value, Inputs, Level 1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at End of Period	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0			0
Foreign Plan | Fair Value, Inputs, Level 1 | Equities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | Fair Value, Inputs, Level 1 | Cash and cash equivalents
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | Fair Value, Inputs, Level 1 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | Fair Value, Inputs, Level 2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	82
Fair Value of Assets at End of Period	92	82
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	82	82		92	82
Foreign Plan | Fair Value, Inputs, Level 2 | Equities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	4
Fair Value of Assets at End of Period	2	4
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	4	4		2	4
Foreign Plan | Fair Value, Inputs, Level 2 | Cash and cash equivalents
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	65
Fair Value of Assets at End of Period	81	65
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	65	65		81	65
Foreign Plan | Fair Value, Inputs, Level 2 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	13
Fair Value of Assets at End of Period	9	13
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	13	13		9	13
Foreign Plan | Fair Value, Inputs, Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | Fair Value, Inputs, Level 3 | Equities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | Fair Value, Inputs, Level 3 | Cash and cash equivalents
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | Fair Value, Inputs, Level 3 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	0
Fair Value of Assets at End of Period	0	0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	0	0		0	0
Foreign Plan | NAV
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	386
Fair Value of Assets at End of Period	441	386
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	386	386		441	386
Foreign Plan | NAV | Equities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	71
Fair Value of Assets at End of Period	86	71
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	71	71		86	71
Foreign Plan | NAV | Fixed income and cash equivalents
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	123
Fair Value of Assets at End of Period	156	123
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	123	123		156	123
Foreign Plan | NAV | Absolute return strategies and other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	110
Fair Value of Assets at End of Period	107	110
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	110	110		107	110
Foreign Plan | Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	475	427
Service cost	5	5
Interest cost	10	13
Actuarial loss/(gain)	28	42
Currency gain	18	13
Benefits paid	(16)	(18)
Plan amendments	(3)	0
Defined Benefit Plan, Settlements / Curtailments	(4)	(7)
Other	4	0
Benefit Obligation at End of Period	523	475	427
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	386	328
Actual return on plan assets	37	50
Currency gain	14	11
Company contributions	21	21
Benefits paid	(16)	(18)
Settlements/curtailments	(4)	(5)
Other	3	(1)
Fair Value of Assets at End of Period	441	386	328
Funded status				(82)	(89)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Prepaid pension cost				12	11
Accrued pension cost – current				(2)	(2)
Accrued pension cost – non-current				(92)	(98)
Net amount recognized				(82)	(89)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial loss				(109)	(97)
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Projected Benefit Obligation				364	329
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Accumulated Benefit Obligation				270	229
Defined Benefit Plan, Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract]
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Accumulated Benefit Obligation				330	295
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Fair Value of Plan Assets				249	205
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	5	5
Settlement/curtailment	$ 0	$ 43	$ 0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	2.24%	3.04%	2.88%
Expected return on plan assets	4.66%	4.91%	5.22%
Rate of compensation increase	3.99%	4.14%	4.29%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	$ 386	$ 386	$ 328	$ 441	$ 386

POSTEMPLOYMENT AND POSTRETIRE_3

POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Accumulated postretirement benefit obligation	$ 177	$ 183
Fair value of plan assets	0	0
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2021	14
2022	14
2023	13
2024	13
2025	12
2026-2030	55
Postemployment Benefits [Abstract]
Postemployment Benefits Liability	8	11
Postemployment Benefits, Period Income	(1)
Postemployment Benefits, Period Expense		1	$ 4
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	183	195
Service cost	1	1	1
Interest cost	6	8	8
Actuarial loss/(gain)	1	(5)
Currency gain	(1)	0
Plan amendments	0	(1)
Benefits paid	(13)	(15)
Benefit Obligation at End of Period	177	183	195
Funded status	(177)	(183)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued benefit obligation – current	(14)	(16)
Accrued benefit obligation – non-current	(163)	(167)
Net amount recognized	(177)	(183)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial gain	43	51
Net prior service credit	2	6
Net amount recognized	45	57
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1	1
Amortization of prior service credit	(4)	(4)	(4)
Amortization of actuarial gain	(8)	(8)	(6)
Net periodic postretirement benefit income	(5)	(3)	(1)
United States
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Accumulated postretirement benefit obligation	163	169
Fair value of plan assets	$ 0	$ 0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.50%	3.30%
United States | Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Employee Eligible Age	10 years
Defined Benefit Plan, Qualifying Employee Age, Scenario 1	45 years
Defined Benefit Plan, Qualifying Employee Age, Scenario 2	48 years
Defined Benefit Plan, Qualifying Employee Age, Scenario 3	50 years
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	$ 169	$ 183
Service cost	1	1
Interest cost	5	7
Actuarial loss/(gain)	0	(7)
Currency gain	0	0
Plan amendments	0	(1)
Benefits paid	(12)	(14)
Benefit Obligation at End of Period	163	169	$ 183
Funded status	(163)	(169)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued benefit obligation – current	(13)	(15)
Accrued benefit obligation – non-current	(150)	(154)
Net amount recognized	(163)	(169)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial gain	41	48
Net prior service credit	2	6
Net amount recognized	$ 43	$ 54
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.25%	3.10%
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 1	$ 1
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	3.10%	4.15%	3.45%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Initial rate at end of year	8.20%	6.50%	6.75%
Ultimate rate	4.50%	5.00%	5.00%
Year in which ultimate rate is reached	2029	2026	2026
Foreign Plan
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Accumulated postretirement benefit obligation	$ 14	$ 14
Fair value of plan assets	$ 0	$ 0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	1.73%	2.24%
Foreign Plan | Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	$ 14	$ 12
Service cost	0	0
Interest cost	1	1
Actuarial loss/(gain)	1	2
Currency gain	(1)	0
Plan amendments	0	0
Benefits paid	(1)	(1)
Benefit Obligation at End of Period	14	14	$ 12
Funded status	(14)	(14)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued benefit obligation – current	(1)	(1)
Accrued benefit obligation – non-current	(13)	(13)
Net amount recognized	(14)	(14)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial gain	2	3
Net prior service credit	0	0
Net amount recognized	$ 2	$ 3
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.04%	3.84%
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 0	$ 0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	3.84%	4.59%	4.56%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Initial rate at end of year	4.10%	5.45%	5.40%
Ultimate rate	3.90%	5.45%	5.40%
Year in which ultimate rate is reached	2040	2019	2019

CONTINGENT LIABILITIES AND OT_2

CONTINGENT LIABILITIES AND OTHER MATTERS (DETAIL) $ in Millions	Dec. 31, 2020USD ($)site
Unusual or Infrequent Item, or Both [Line Items]
Environmental liability sites	21
Environmental liabilities reserve | $	$ 7
Superfund Sites
Unusual or Infrequent Item, or Both [Line Items]
Environmental liability sites	8
Owned or Formerly Owned Sites
Unusual or Infrequent Item, or Both [Line Items]
Environmental liability sites	13
Other Current Liabilities
Unusual or Infrequent Item, or Both [Line Items]
Environmental liabilities reserve | $	$ 3

STOCK COMPENSATION (DETAIL)

STOCK COMPENSATION (DETAIL) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 15, 2021	Apr. 16, 2020	Apr. 18, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grants, weighted average grant date fair value	$ 63.96	$ 52.60	$ 84.34
Intrinsic value of options outstanding	$ 14	$ 11
Intrinsic value of options exercisable	$ 14
Outstanding Options, Weighted Average Remaining Contractual Term	1 year 6 months	3 years 21 days
Exercisable Options, Weighted Average Remaining Contractual Term	1 year 6 months
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Options, Outstanding, Number, Beginning Balance	414,800
Options, Outstanding, Number, Options Exercised	(53,025)
Options, Outstanding, Number, Ending Balance	361,775	414,800
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options, Outstanding, Weighted Average Exercise Price, Beginning of Period	$ 37.79
Options, Outstanding, Exercises In Period Weighted Average Exercise Price	37.90
Options, Outstanding, Weighted Average Exercise Price, End of Period	$ 37.77	$ 37.79
Marketing and Administrative Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 41	$ 39	$ 47
Tax benefit from exercise of stock options	$ 14	$ 7	$ 24
Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contributions from employees				$ 4
Stock Plan 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant	3,500,000
Performance Stock Units (PSUs) 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grants, weighted average grant date fair value		$ 68.65
Expected volatility rate		26.67%
Risk free interest rate		2.45%
Expected term		2 years 10 months 24 days
Performance Stock Units (PSUs) 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grants, weighted average grant date fair value			$ 94.14
Expected volatility rate			24.56%
Risk free interest rate			2.22%
Expected term			2 years 11 months 1 day
Performance Stock Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonoptions, Number, Beginning Balance	312,725
Nonoptions, Number, Grants In Period	169,539
Nonoptions, Number, Vested In Period	(98,842)
Nonoptions, Number, Forfeited In Period	(60,061)
Nonoptions, Number, Ending Balance	323,361	312,725
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonoptions, Weighted Average Fair Value, Beginning Balance	$ 69.23
Nonoptions, Weighted Average Fair Value, Grants in Period	65.29
Nonoptions, Weighted Average Fair Value, Vested	95.43
Nonoptions, Weighted Average Fair Value, Forfeited	74.09
Nonoptions, Weighted Average Fair Value, Ending Balance	$ 69.20	$ 69.23
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant	4,100,000				4,200,000
Internal Based Performance Metric
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)	3 years
Percentage of outstanding stock minimum	0.00%
Percentage of outstanding stock maximum	300.00%
External Based Performance Metric
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)	3 years
Percentage of outstanding stock minimum	0.00%
Percentage of outstanding stock maximum	200.00%
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Tax benefit from exercise of stock options	$ 0	$ 0	$ 0
Award vesting period (in years)	4 years
Options maximum term	10 years
Cash received from exercise of stock options	$ 2	2	1
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)	2 years 3 months 21 days
Total unrecognized compensation cost related to restricted stock	$ 32
Grants in period fair value	$ 27	$ 21	23
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonoptions, Number, Beginning Balance	1,515,706
Nonoptions, Number, Grants In Period	513,111
Nonoptions, Number, Vested In Period	(515,247)
Nonoptions, Number, Forfeited In Period	(94,116)
Nonoptions, Number, Ending Balance	1,419,454	1,515,706
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonoptions, Weighted Average Fair Value, Beginning Balance	$ 51.70
Nonoptions, Weighted Average Fair Value, Grants in Period	63.96
Nonoptions, Weighted Average Fair Value, Vested	51.50
Nonoptions, Weighted Average Fair Value, Forfeited	67.09
Nonoptions, Weighted Average Fair Value, Ending Balance	$ 54.99	$ 51.70
Restricted Stock Awards and Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)	4 years
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)	1 year 9 months 25 days
Total unrecognized compensation cost related to restricted stock	$ 13
Grants in period fair value	9	$ 14	23
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost related to restricted stock	2
Purchase price, percentage of market value						85.00%
Employee emergence equity program expense	$ 6	$ 5	$ 4
Shares purchased by employees	366,442	393,230	295,407
Average price of shares purchased	$ 45.17	$ 41.33	$ 48.93
Minimum | Performance Stock Units (PSUs) 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grants, weighted average grant date fair value	$ 68.60
Expected volatility rate	28.43%
Risk free interest rate	0.15%
Expected term	2 years 3 months 21 days
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable Options, Weighted Average Exercise Price	$ 33.73
Maximum | Performance Stock Units (PSUs) 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grants, weighted average grant date fair value	$ 76.58
Expected volatility rate	44.83%
Risk free interest rate	1.43%
Expected term	2 years 10 months 24 days
Maximum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable Options, Weighted Average Exercise Price	$ 42.16

CHANGES IN ACCUMULATED OTHER _3

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ (610)
Ending balance	(588)	$ (610)
Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(282)	(306)
Net investment hedge amounts classified into AOCI, net of tax	11	13
Gain on foreign currency translation	51	11
Other comprehensive income/(loss), net of tax	62	24
Ending balance	(220)	(282)
Pension and Other Postretirement Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(326)	(350)
Amounts reclassified from AOCI to net earnings, net of tax	3	35
Amounts classified into AOCI, net of tax	(49)	(11)
Other comprehensive income/(loss), net of tax	(46)	24
Ending balance	(372)	(326)
Hedging Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2)	0
Amounts reclassified from AOCI to net earnings, net of tax	4	3
Amounts classified into AOCI, net of tax	2	(5)
Other comprehensive income/(loss), net of tax	6	(2)
Ending balance	$ 4	$ (2)

EARNINGS PER SHARE (DETAIL)

EARNINGS PER SHARE (DETAIL) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
NET EARNINGS ATTRIBUTABLE TO OWENS CORNING	$ (383)	$ 405	$ 545
Weighted-average number of shares outstanding used for basic earnings (loss) per share	108.6	109.2	110.4
Non-vested restricted and performance shares	0	0.7	0.8
Options to purchase common stock	0	0.2	0.2
Weighted-average number of shares outstanding and common equivalent shares used for diluted earnings (loss) per share		110.1	111.4
Basic (dollars per share)	$ (3.53)	$ 3.71	$ 4.94
Diluted (dollars per share)	$ (3.53)	$ 3.68	$ 4.89

EARNINGS PER SHARE - Narrative

EARNINGS PER SHARE - Narrative (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Oct. 24, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Payments for repurchase of equity	$ 292
Remaining number of shares authorized to be repurchased	9,500,000
Performance Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		300,000
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		300,000
Repurchase Program 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares authorized to be repurchased			10,000,000
Combined Repurchase Programs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Purchase of treasury stock (in shares)	4,100,000

INCOME TAXES (DETAIL)

INCOME TAXES (DETAIL) - USD ($)	Jul. 20, 2020	Mar. 06, 2019	Dec. 18, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Earnings Before Taxes, Domestic				$ 8,000,000	$ 315,000,000	$ 411,000,000
Earnings Before Taxes, Foreign				(264,000,000)	275,000,000	293,000,000
EARNINGS (LOSS) BEFORE TAXES				(256,000,000)	590,000,000	704,000,000
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)				4,000,000	(4,000,000)	(10,000,000)
Current State and Local Tax Expense (Benefit)				16,000,000	11,000,000	6,000,000
Current Foreign Tax Expense (Benefit)				30,000,000	60,000,000	19,000,000
Current Income Tax Expense (Benefit)				50,000,000	67,000,000	15,000,000
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred Federal Income Tax Expense (Benefit)				64,000,000	112,000,000	114,000,000
Deferred State and Local Income Tax Expense (Benefit)				(1,000,000)	11,000,000	12,000,000
Deferred Foreign Income Tax Expense (Benefit)				16,000,000	(4,000,000)	15,000,000
Deferred Income Tax Expense (Benefit)				79,000,000	119,000,000	141,000,000
Total income tax expense				$ 129,000,000	$ 186,000,000	$ 156,000,000
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
United States federal statutory rate				21.00%	21.00%	21.00%
State and local income taxes, net of federal tax benefit				(9.00%)	3.00%	2.00%
U.S. tax expense on foreign earnings				(5.00%)	1.00%	2.00%
Legislative tax rate changes				7.00%	2.00%	0.00%
Foreign tax credits				(2.00%)	0.00%	0.00%
Valuation allowance				(15.00%)	3.00%	2.00%
Intercompany restructuring - intellectual property transfer				14.00%	0.00%	0.00%
Goodwill impairment charge				(75.00%)	0.00%	0.00%
Uncertain tax positions and settlements				2.00%	0.00%	(5.00%)
Excess tax benefits related to stock compensation				2.00%	0.00%	(2.00%)
Other, net				6.00%	1.00%	2.00%
Effective tax rate				(50.00%)	31.00%	22.00%
Deferred tax asset, intercompany restructuring				$ 37,000,000
Income tax expense, intercompany restructuring				5,000,000
Income Tax Expense (Benefit), GILTI	$ 13,000,000	$ 12,000,000
Cumulative effect adjustment				3,901,000,000	$ 4,631,000,000
Undistributed earnings of foreign subsidiaries				1,200,000,000
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Other Employee Benefits				71,000,000	76,000,000
Deferred Tax Assets, Pension Plans				41,000,000	54,000,000
Deferred Tax Assets, Operating Loss Carryforwards				170,000,000	195,000,000
Deferred Tax Asset, Lease Liability				33,000,000	49,000,000
Deferred Tax Assets, Operating Loss Carryforwards, Foreign				49,000,000	97,000,000
Deferred Tax Assets, State and Local				0	3,000,000
Deferred Tax Assets, Other				90,000,000	76,000,000
Deferred Tax Assets, Gross				454,000,000	550,000,000
Valuation Allowance, Amount				133,000,000	92,000,000
Deferred Tax Assets Total				321,000,000	458,000,000
Components of Deferred Tax Liabilities [Abstract]
Deferred Tax Liabilities, Depreciation				259,000,000	247,000,000
Deferred Tax Liabilities, Right of Use Assets				33,000,000	49,000,000
Deferred Tax Liabilities, Amortization				333,000,000	388,000,000
Deferred Tax Liabilities Total				625,000,000	684,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
U.S. federal loss carryforwards				23,000,000
U.S. state loss carryforwards				37,000,000
Foreign loss and tax credit carryforwards				41,000,000
Foreign loss and tax credit carryforwards				66,000,000
Other U.S. federal and state tax credits				3,000,000
U.S foreign tax credits				49,000,000
US State Deferred Tax Asset Related to Loss Carryforwards Set to Expire				12,000,000
Foreign Deferred Tax Asset Related to Loss Carryforwards Set to Expire				7,000,000
Federal Earnings Before Tax Needed				111,000,000
State Earnings Before Tax Needed				1,115,000,000
Foreign Earnings Before Tax Needed				395,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits, Beginning Balance				79,000,000	84,000,000	$ 90,000,000
Tax Positions Related to Current Year, Gross Additions				0	0	6,000,000
Tax Positions Related to Prior Years, Gross Additions				2,000,000	1,000,000	36,000,000
Tax Positions Related to Prior Years, Gross Reductions				(1,000,000)	0	(37,000,000)
Settlements			$ (32,000,000)	(1,000,000)	(1,000,000)	(5,000,000)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations				(3,000,000)	(5,000,000)	(4,000,000)
Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation				0	0	(2,000,000)
Unrecognized Tax Benefits, Ending Balance				76,000,000	79,000,000	84,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate				59,000,000
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities			$ 32,000,000	1,000,000	1,000,000	5,000,000
Income Tax Penalties and Interest [Abstract]
Income Tax Examination, Penalties and Interest Accrued				7,000,000	8,000,000	10,000,000
Income Tax Examination, Penalties and Interest Expense					2,000,000	$ 1,000,000
Minimum
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Unrecognized Tax Benefits Estimated Range of Change Lower Bound				0
Maximum
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Unrecognized Tax Benefits Estimated Range of Change Lower Bound				4,000,000
Domestic Tax Authority
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Gross				140,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				111,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Tax Positions Related to Current Year, Gross Additions				49,000,000	43,000,000
Domestic Tax Authority | Minimum
Components of Deferred Tax Assets [Abstract]
Valuation Allowance, Amount				0
Domestic Tax Authority | Maximum
Components of Deferred Tax Assets [Abstract]
Valuation Allowance, Amount				9,000,000
State and Local Jurisdiction
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Gross				1,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				1,160,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Tax Positions Related to Current Year, Gross Additions				7,000,000	11,000,000
Foreign Tax Authority
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Gross				31,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				418,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Tax Positions Related to Current Year, Gross Additions				$ 77,000,000	$ 38,000,000

SCHEDULE II - VALUATION AND Q_3

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (DETAIL) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 11	$ 16	$ 19
Charged to Costs and Expenses		1	2	0
Charged to Other Accounts		0	0	0
Deductions	[1]	(2)	(7)	(4)
Acquisitions and Divestitures		0	0	1
Balance at End of Period		10	11	16
Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		92	78	94
Charged to Costs and Expenses		39	19	13
Charged to Other Accounts		2	1	(4)
Deductions		0	(6)	(31)
Acquisitions and Divestitures		0	0	6
Balance at End of Period		$ 133	$ 92	$ 78
[1]	Uncollectible accounts written off, net of recoveries.