Owens Corning (OC) 10-K 20 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 15, 2019	Jun. 29, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Owens Corning
Entity Central Index Key	1,370,946
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 7,029,117,335
Entity Common Stock, Shares Outstanding		109,579,002

CONSOLIDATED STATEMENTS OF EARN

CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
NET SALES	$ 7,057	$ 6,384	$ 5,677
COST OF SALES	5,425	4,815	4,300
Gross margin	1,632	1,569	1,377
OPERATING EXPENSES
Marketing and administrative expenses	700	620	584
Science and technology expenses	89	85	82
Other expenses, net	36	67	14
Total operating expenses	825	772	680
OPERATING INCOME	807	797	697
Non-operating (income) expense	(14)	60	(2)
EARNINGS BEFORE INTEREST AND TAXES	821	737	699
Interest expense, net	117	107	108
Loss on extinguishment of debt	0	71	1
EARNINGS BEFORE TAXES	704	559	590
Income tax expense	156	269	188
Equity in loss of affiliates	(1)	0	(3)
NET EARNINGS	547	290	399
Net earnings attributable to noncontrolling interests	2	1	6
NET EARNINGS ATTRIBUTABLE TO OWENS CORNING	$ 545	$ 289	$ 393
EARNINGS PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS
Basic (dollars per share)	$ 4.94	$ 2.59	$ 3.44
Diluted (dollars per share)	4.89	2.55	3.41
Dividend (dollars per share)	$ 0.85	$ 0.81	$ 0.74
WEIGHTED AVERAGE COMMON SHARES
Basic (in shares)	110.4	111.5	114.4
Diluted (in shares)	111.4	113.2	115.4

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
NET EARNINGS	$ 547	$ 290	$ 399
Currency translation adjustment (net of tax of $(4), $15 and $(2), for the periods ended December 31, 2018, 2017 and 2016, respectively)	(123)	101	(37)
Pension and other postretirement adjustment (net of tax of $6, $(32) and $15, for the periods ended December 31, 2018, 2017 and 2016, respectively)	(19)	98	(10)
Hedging adjustment (net of tax of $0, $2 and $(3), for the periods ended December 31, 2018, 2017 and 2016, respectively)	0	(3)	7
COMPREHENSIVE EARNINGS	405	486	359
Comprehensive earnings attributable to noncontrolling interests	2	1	6
COMPREHENSIVE EARNINGS ATTRIBUTABLE TO OWENS CORNING	$ 403	$ 485	$ 353

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (LOSS) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Currency translation tax	$ (4)	$ 15	$ (2)
Pension and other postretirement tax	6	(32)	15
Hedging tax	$ 0	$ 2	$ (3)

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents		$ 78	$ 246
Receivables, less allowances of $16 at December 31, 2018 and $19 at December 31, 2017		794	806
Inventories		1,072	841
Assets held for sale		3	12
Other current assets		73	80
Total current assets		2,020	1,985
Property, plant and equipment, net		3,811	3,425
Goodwill		1,949	1,507
Intangible assets, net		1,779	1,360
Deferred income taxes		43	144
Other non-current assets		169	211
TOTAL ASSETS		9,771	8,632
LIABILITIES AND EQUITY
Total current liabilities		1,278	1,282
Long-term debt, net of current portion		3,362	2,405
Pension plan liability		268	256
Other employee benefits liability		190	225
Deferred income taxes		141	37
Other liabilities		208	223
OWENS CORNING STOCKHOLDERS’ EQUITY
Preferred stock, par value $0.01 per share (a)	[1]	0	0
Common stock, par value $0.01 per share (b)	[2]	1	1
Additional paid in capital		4,028	4,011
Accumulated earnings		2,013	1,575
Accumulated other comprehensive deficit		(656)	(514)
Cost of common stock in treasury (c)	[3]	(1,103)	(911)
Total Owens Corning stockholders’ equity		4,283	4,162
Noncontrolling interests		41	42
Total equity		4,324	4,204
TOTAL LIABILITIES AND EQUITY		$ 9,771	$ 8,632
[1]	10 shares authorized; none issued or outstanding at December 31, 2018 and December 31, 2017
[2]	400 shares authorized; 135.5 issued and 109.5 outstanding at December 31, 2018; 135.5 issued and 111.5 outstanding at December 31, 2017
[3]	26.0 shares at December 31, 2018 and 24.0 shares at December 31, 2017

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 16	$ 19
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	109,500,000	111,500,000
Treasury stock shares	26,000,000	24,000,000

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	[2]	NCI
Beginning balance (in shares) at Dec. 31, 2015			115.9	19.6
Beginning balance at Dec. 31, 2015		$ 3,779	$ 1	$ (612)	$ 3,965		$ 1,055		$ (670)		$ 40	[3]
Increase Decrease In Stockholders Equity [Roll Forward]
Net earnings attributable to Owens Corning		393					393				0	[3]
Net earnings attributable to noncontrolling interests		6									6	[3]
Currency translation adjustment		(39)							(37)		(2)	[3]
Pension and other postretirement adjustment (net of tax)		(10)							(10)
Deferred gain on hedging transactions (net of tax)		7							7
Redeemable equity issued		(2)			(2)						0	[3]
Issuance of common stock under share-based payment plans (in shares)			1.7	1.7
Issuance of common stock under share-based payment plans		37		$ 57	(20)
Purchase of treasury stock (in shares)			4.9	4.9
Purchases of treasury stock		(248)		$ (248)
Stock-based compensation expense		41			41
Cumulative effect of accounting change	[4]	14					14
Dividends declared		(89)					(85)
Dividends declared											(4)
Ending balance (in shares) at Dec. 31, 2016			112.7	22.8
Ending balance at Dec. 31, 2016		3,889	$ 1	$ (803)	3,984		1,377		(710)		40	[3]
Increase Decrease In Stockholders Equity [Roll Forward]
Net earnings attributable to Owens Corning		289					289				0	[3]
Net earnings attributable to noncontrolling interests		1									1	[3]
Currency translation adjustment		105							101		4	[3]
Pension and other postretirement adjustment (net of tax)		98							98
Deferred gain on hedging transactions (net of tax)		(3)							(3)
Redeemable equity redeemed and changes in subsidiary shares from noncontrolling interests		1			2		(1)	[3]
Issuance of common stock under share-based payment plans (in shares)			1.3	1.3
Issuance of common stock under share-based payment plans		29		$ 48	(19)
Purchase of treasury stock (in shares)			2.5	2.5
Purchases of treasury stock		(156)		$ (156)
Stock-based compensation expense		44			44
Dividends declared		(93)					(91)
Dividends declared	[3]										(2)
Ending balance (in shares) at Dec. 31, 2017			111.5	24
Ending balance at Dec. 31, 2017		4,204	$ 1	$ (911)	4,011		1,575		(514)		42	[3]
Increase Decrease In Stockholders Equity [Roll Forward]
Net earnings attributable to Owens Corning		545					545				0	[3]
Net earnings attributable to noncontrolling interests		2									2	[3]
Currency translation adjustment		(125)							(123)		(2)	[3]
Pension and other postretirement adjustment (net of tax)		(19)							(19)
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	[4]	12					12
Dividends declared		(96)					(95)
Dividends declared	[3]										(1)
Ending balance (in shares) at Dec. 31, 2018			109.5	26
Ending balance at Dec. 31, 2018		$ 4,324	$ 1	$ (1,103)	$ 4,028		$ 2,013		$ (656)		$ 41	[3]
[1]	Additional Paid in Capital (APIC)
[2]	Accumulated Other Comprehensive Earnings (Deficit) (“AOCI”)
[3]	Noncontrolling Interest (“NCI”)
[4]	Cumulative effect of accounting change relates to our adoption of ASU 2016-09 "Compensation - Stock Compensation (Topic 718)."

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
NET CASH FLOW PROVIDED BY OPERATING ACTIVITIES
NET EARNINGS	$ 547	$ 290	$ 399
Adjustments to reconcile net earnings to cash provided by operating activities:
Depreciation and amortization	433	371	343
Deferred income taxes	141	183	136
Provision for pension and other employee benefits liabilities	0	74	11
Stock-based compensation expense	47	44	41
Loss on extinguishment of debt	0	71	1
Other adjustments to reconcile net earnings to cash provided by operating activities	(49)	18	4
Changes in receivables, net	39	(66)	55
Changes in inventories	(216)	(57)	5
Changes in accounts payable and accrued liabilities	(89)	187	25
Changes in other operating assets and liabilities	7	(10)	(4)
Pension fund contributions	(40)	(72)	(63)
Payments for other employee benefits liabilities	(19)	(18)	(18)
Other	2	1	8
Net cash flow provided by operating activities	803	1,016	943
NET CASH FLOW USED FOR INVESTING ACTIVITIES
Cash paid for property, plant and equipment	537	337	373
Derivative settlements	64	3	4
Proceeds from the sale of assets or affiliates	27	3	0
Investment in subsidiaries and affiliates, net of cash acquired	(1,143)	(570)	(452)
Other	0	0	6
Net cash flow used for investing activities	(1,589)	(901)	(815)
NET CASH FLOW PROVIDED BY (USED FOR) FINANCING ACTIVITIES
Proceeds from senior revolving credit and receivables securitization facilities	1,954	1,133	669
Payments on senior revolving credit and receivables securitization facilities	(1,879)	(1,133)	(669)
Proceeds from term loan borrowing	600	0	300
Payments on term loan borrowing	(100)	0	(300)
Proceeds from long-term debt	389	588	395
Payments on long-term debt	0	(351)	(163)
Dividends paid	(92)	(89)	(81)
Net increase (decrease) in short-term debt	16	1	(6)
Purchases of treasury stock	(236)	(159)	(247)
Other	(5)	13	14
Net cash flow provided by (used for) financing activities	647	3	(88)
Effect of exchange rate changes on cash	(29)	17	(18)
Net (decrease) increase in cash, cash equivalents and restricted cash	(168)	135	22
Cash, cash equivalents and restricted cash at beginning of period	253	118	96
Cash, cash equivalents and restricted cash at end of period	85	253	118
Cash paid during the year for income taxes	91	67	69
Cash paid during the year for interest	$ 158	$ 106	$ 118

BUSINESS AND SUMMARY OF SIGNIFI

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Description of Business Owens Corning, a Delaware corporation, is a leading global producer of glass fiber reinforcements and other materials for composite systems and of residential and commercial building materials. The Company operates within three segments: Composites, which includes the Company’s Reinforcements and Downstream businesses; 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 7, 2019, the Board of Directors declared a quarterly dividend of $0.22 per common share payable on April 2, 2019 to shareholders of record as of March 8, 2019. 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 2017 and 2016 Consolidated Financial Statements and Notes to the Consolidated Financial Statements to conform to the classifications used in 2018 . 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 Accounts payable and accrued 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 11. 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 $2 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 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 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. 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, 2018 , 2017 and 2016 were $120 million , $108 million and $105 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 per share are computed using the weighted-average number of common shares outstanding during the period. Diluted earnings 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 , $7 million and $6 million as of December 31, 2018, 2017 and 2016, respectively. 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. The allowance for doubtful accounts is an estimate of the amount of probable credit losses in our existing accounts receivable. 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, 2018 and 2017 , the total value of investments was $51 million and $52 million , respectively. 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 estimates in the discounted cash flow approach are cash flow forecasts of our reporting units, the discount rate, the terminal business value and the projected income tax rate. 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 projected income tax rates utilized are the statutory tax rates for the countries where each reporting unit operates. The terminal business value is determined by applying a business growth factor 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 projected cash flows, royalty rates, discount rate, projected income tax rate and terminal business 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. Identifiable intangible assets with a determinable useful life are amortized over that determinable life. Amortization expense for the years ended December 31, 2018 , 2017 and 2016 was $49 million , $31 million and $25 million , respectively. See Note 6 for further discussion. 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. For the years ended December 31, 2018 , 2017 and 2016 , depreciation expense was $384 million , $340 million and $318 million , respectively. In 2018 , 2017 and 2016 , depreciation expense included $10 million , $17 million and $19 million , respectively, of accelerated depreciation related to restructuring actions further explained in Note 12 to the Consolidated Financial Statements. 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 would be material to the Company’s Consolidated Financial Statements in any given period. 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. Please refer to Note 20 for information on the Company's application of SEC Staff Accounting Bulletin No. 118, "Income Tax Accounting Implications of the Tax Cuts and Jobs Act," ("SAB 118") on the estimates used to record the effects of the tax legislation commonly known as the U.S. Tax Cuts and Jobs Act of 2017 (the "Tax Act"). 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 5 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 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. 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, 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 5 and 13 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 recored in Other expenses, net in the Consolidated Statements of Earnings 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 $7 million during the year ended December 31, 2018 and foreign currency transactional losses (net of associated derivative activity) of $4 million and $2 million during the years ended 2017 and 2016 , respectively. Please refer to Note 5 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 2014-09 "Revenue from Contracts with Customers (Topic 606)," as amended by ASU's 2015-14, 2016-08, 2016-10, 2016-11, 2016-12, 2016-20, 2017-05 and 2017-13 and 2017-14 This standard outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. Entities can adopt this standard either through a retrospective or modified-retrospective approach. January 1, 2018 The adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to Note 3 for transition disclosures, as well as other ongoing disclosure requirements. ASU 2016-16 "Income Taxes (Topic 740)" This standard requires that an entity recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. January 1, 2018 The adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to Note 20 of the Consolidated Financial Statements for a detailed explanation of the cumulative effect of adoption recognized on January 1, 2018. ASU 2017-07 "Compensation - Retirement Benefits (Topic 715)" This standard requires that the other components of net benefit cost be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. Retrospective application is required upon adoption of the presentation elements of this standard. January 1, 2018 The adoption of this standard did not have a material effect on our Consolidated Financial Statements for the year ended December 31, 2018. The standard's retrospective adoption, though, resulted in a full-year $60 million reclassification of non-service costs from various financial statement lines to non-operating expense, primarily related to pension settlement losses that were recorded in 2017. Please refer to Note 14 for additional detail on this adoption. ASU 2017-12 "Derivatives and Hedging (Topic 815)" This standard changes how an entity assesses effectiveness of derivative instruments, potentially resulting in less ineffectiveness and more derivatives qualifying for hedge accounting. Entities may early adopt the standard in any interim period, with the effect of adoption being applied to existing hedging relationships as of the beginning of the fiscal year of adoption. January 1, 2018 The early adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to Note 5 of the Consolidated Financial Statements for additional detail on this adoption. Recently issued standards: ASU 2016-02 "Leases (Topic 842)," as amended by ASU 2017-13, 2018-01, 2018-10, and 2018-11 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 The Company will adopt the accounting standard using the optional transition method, allowing us to record the cumulative effect adjustment of adopting the standard in the period of adoption, without restating prior periods presented. We are finalizing our assessment of our lease portfolio, implementation of systems, development of processes and internal controls and our accounting policy elections to comply with the standard's adoption requirements. We anticipate adoption of the standard will add approximately $200 to $250 million in right-of-use assets and lease obligations to our consolidated balance sheet and will not significantly impact results. (Our operating lease obligations are described in Note 9 of the Consolidated Financial Statements.) ASU 2016-13 "Financial Instruments - Credit Losses (Topic 326)" 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 are currently assessing the impact this standard will have on our Consolidated Financial Statements. Our current accounts receivable policy (as described in Note 1 of the Consolidated Financial Statements) uses historical and current information to estimate the amount of probable credit losses in our existing accounts receivable. We have not yet analyzed our current systems and methods to determine the impact of using forward-looking information to estimate expected credit losses. 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 do not believe the adoption of this guidance will have a material effect on our consolidated financial statements.

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2018
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 Composites segment includes vertically integrated downstream activities. 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 table summarizes our net sales by segment and geographic region (in millions). Corporate eliminations (shown below) largely reflect the 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, 2018 2017 2016 Reportable Segments Composites $ 2,041 $ 2,068 $ 1,952 Insulation 2,720 2,001 1,748 Roofing 2,492 2,553 2,194 Total reportable segments 7,253 6,622 5,894 Corporate eliminations (196 ) (238 ) (217 ) NET SALES $ 7,057 $ 6,384 $ 5,677 External Customer Sales by Geographic Region United States $ 4,647 $ 4,495 $ 3,963 Europe 1,209 661 550 Asia Pacific 656 675 666 Canada and other 545 553 498 NET SALES $ 7,057 $ 6,384 $ 5,677 EARNINGS BEFORE INTEREST AND TAXES Earnings 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 in the Corporate, Other and Eliminations category. The following table summarizes EBIT by segment (in millions): Twelve Months Ended December 31, 2018 2017 2016 Reportable Segments Composites $ 251 $ 291 $ 264 Insulation 290 177 126 Roofing 434 535 486 Total reportable segments 975 1,003 876 Restructuring costs (22 ) (48 ) (28 ) Acquisition-related costs (16 ) (15 ) (9 ) Recognition of acquisition inventory fair value step-up (2 ) (5 ) (10 ) Litigation settlement gain, net of legal fees — 29 — Pension settlement losses — (64 ) — Environmental liability charges — (15 ) — General corporate expense and other (114 ) (148 ) (130 ) Total Corporate, other and eliminations $ (154 ) $ (266 ) $ (177 ) EBIT $ 821 $ 737 $ 699 TOTAL ASSETS AND PROPERTY, PLANT AND EQUIPMENT BY GEOGRAPHIC REGION The following table summarizes total assets by segment and property, plant and equipment by geographic region (in millions): December 31, TOTAL ASSETS 2018 2017 Reportable Segments Composites $ 2,480 $ 2,486 Insulation 4,907 3,618 Roofing 1,750 1,621 Total reportable segments 9,137 7,725 Cash and cash equivalents 78 246 Noncurrent deferred income taxes 43 144 Investments in affiliates 51 52 Assets held for sale 3 12 Corporate property, plant and equipment, other assets and eliminations 459 453 CONSOLIDATED TOTAL ASSETS $ 9,771 $ 8,632 December 31, PROPERTY, PLANT AND EQUIPMENT BY GEOGRAPHIC REGION 2018 2017 United States $ 2,166 $ 2,164 Europe 779 479 Asia Pacific 567 459 Canada and other 299 323 TOTAL PROPERTY, PLANT AND EQUIPMENT $ 3,811 $ 3,425 PROVISION FOR DEPRECIATION AND AMORTIZATION The following table summarizes the provision for depreciation and amortization by segment (in millions): Twelve Months Ended December 31, 2018 2017 2016 Reportable Segments Composites $ 147 $ 144 $ 138 Insulation 186 124 106 Roofing 51 50 46 Total reportable segments 384 318 290 General corporate depreciation and amortization (a) 49 53 53 CONSOLIDATED PROVISION FOR DEPRECIATION AND AMORTIZATION $ 433 $ 371 $ 343 (a) In 2018 , 2017 and 2016, General corporate depreciation and amortization expense included $10 million , $17 million and $19 million , respectively, of accelerated depreciation related to restructuring actions further explained in Note 12 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, 2018 2017 2016 Reportable Segments Composites (a) $ 154 $ 148 $ 152 Insulation 240 151 154 Roofing 91 66 66 Total reportable segments 485 365 372 General corporate additions 57 37 42 CONSOLIDATED ADDITIONS TO PROPERTY, PLANT AND EQUIPMENT $ 542 $ 402 $ 414 (a) The 2018 figure for Composites includes $12 million of capital expenditures related to an acquired non-wovens plant, which was accounted for as an asset acquisition.

REVENUE (NOTE)

REVENUE (NOTE)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE ASU 2014-09 Adoption On January 1, 2018, we adopted ASU 2014-09 "Revenue from Contracts with Customers (Topic 606)" and the related amendments (collectively, "ASC 606"). We used the modified retrospective method of adoption, in which the cumulative effect of initially applying the new standard to existing contracts (as of January 1, 2018) was recorded as a $2 million decrease to the January 1, 2018 opening balance of Accumulated earnings. The effect of this adoption was immaterial to our Consolidated Financial Statements, and we do not expect a material effect to our Consolidated Financial Statements on an ongoing basis. Under the modified-retrospective method of adoption, the comparative information in the Consolidated Financial Statements has not been revised and continues to be reported under the previously applicable revenue accounting guidance ("ASC 605"). If ASC 605 had been applied to the year 2018, the impact would have been immaterial to our Consolidated Financial Statements. Please refer to Significant Policies in Note 1 for other disclosures required by ASC 606. Disaggregated Revenue The following table shows a disaggregation of Net sales (in millions): For the 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 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 Please refer to Note 2 and Item 1 of our 2018 Form 10-K for further information on our three reportable segments (Composites, Insulation and Roofing). 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 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. 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 in each respective geographical region. Contract Balances As of January 1, 2018, our contract liability balances (for extended warranties, down payments and deposits, collectively) totaled $46 million , of which $14 million was recognized as revenue throughout 2018. As of December 31, 2018, our contract liability balances totaled $53 million .

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2018
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, 2018 and 2017 , 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. During 2018 , the Company early adopted ASU 2017-12, "Derivatives and Hedging (Topic 815)," which was issued with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements and to make certain targeted improvements to simplify the application of previously applicable hedge accounting guidance. This adoption did not have a material effect on our Consolidated Financial Statements, and did not result in any cumulative adjustment to equity as of the date of adoption. Please refer to the Cash Flow Hedges and Net Investment Hedges paragraphs below for further information. Derivative Fair Values 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, 2018 December 31, 2017 Derivative assets designated as hedging instruments: Net investment hedges: Cross currency swaps Other current assets $ 9 $ 7 Cash flow hedges: Natural gas forward swaps Other current assets $ — $ 1 Derivative liabilities designated as hedging instruments: Net investment hedges: Cross-currency swaps Other liabilities $ 17 $ 38 Cash flow hedges: Natural gas forward swaps Accounts payable and accrued liabilities $ 1 $ 1 Derivative assets not designated as hedging instruments: Foreign exchange forward contracts Other current assets $ 1 $ 1 Derivative liabilities not designated as hedging instruments: Foreign exchange forward contracts Accounts payable and accrued liabilities $ 8 $ 1 Consolidated Statements of Earnings Activity The following table presents the impact and respective location of derivative activities on the Consolidated Statements of Earnings (in millions): Twelve Months Ended Location 2018 2017 2016 Derivative activity designated as hedging instruments: Natural gas cash flow hedges: Amount of (gain)/loss reclassified from AOCI into earnings Cost of sales $ (2 ) $ (1 ) $ 6 Amount of loss recognized in earnings (ineffective portion) Other expenses, net $ — $ 2 $ — Cross-currency swap net investment hedges: Amount of gain recognized in earnings on derivative amounts excluded from effectiveness testing Interest expense, net $ (12 ) $ — $ — Derivative activity not designated as hedging instruments: Natural gas: Amount of gain recognized in earnings Other expenses, net $ — $ — $ (2 ) Foreign currency: Amount of (gain)/loss recognized in earnings (a) Other expenses, net $ (55 ) $ 5 $ 3 (a) (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 Activity The following table presents the impact of derivative activities on the Consolidated Statements of Comprehensive Earnings (in millions): Amount of (Gain) Loss Recognized in Comprehensive Earnings Twelve Months Ended December 31, Hedging Type Derivative Financial Instrument 2018 2017 Net investment hedge Cross-currency swaps $ (18 ) $ 38 Cash flow hedge Natural gas forward swaps $ — $ 4 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. The Company's policy for electricity exposure is to hedge up to 75% of its total forecasted exposure for the current calendar year and up to 65% of its total forecasted exposure for the first calendar year forward. The Company’s policy for natural gas exposure is to hedge up to 75% of its total forecasted exposure for the next three months and up to 60% of its total forecasted exposure for the following three months, and lesser amounts for the remaining periods. Based on market conditions, approved variation from these standard policies may occur for certain geographic regions. Currently, the Company is managing risk associated with electricity prices only through physical contracts and has natural gas derivatives designated as hedging instruments that mature within 15 months. As of December 31, 2018, the notional amounts of these natural gas forward swaps was 2 MMBTu (or MMBTu equivalent based on U.S. and European indices), which is down from 5 MMBTu at December 31, 2017 due to reduced notional hedging in the U.S. As of December 31, 2018, the Company had notional amounts of $4 million for derivative financial instruments designated as cash flow hedges for foreign currency exposures in Polish Zloty primarily related to European Euro, and $8 million for exposures in Swedish Krona primarily related to European Euro. 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 a portion of the net investment in foreign subsidiaries against fluctuations in foreign exchange rates. As of December 31, 2018 , the notional amount of these derivative financial instruments was $516 million related to the U.S Dollar and European Euro. In 2018 , we redesignated these derivative financial instruments that qualify as hedges of net investments in foreign operations using the spot method. 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. For 2018 , the difference between the change in fair value of the excluded components and the amounts recognized to earnings was a $14 million increase to Accumulated other comprehensive deficit. Prior to our first quarter 2018 adoption of ASU 2017-12, all settlements and changes in fair values of these derivative instruments were recognized in Currency translation adjustment (a component of AOCI), and there has been no ineffectiveness on these hedging relationships. 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, 2018 , the Company had notional amounts of $731 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, Indian Rupee, Japanese Yen, and South Korean Won. The growth in notional amounts (as compared to $109 million at December 31, 2017) was primarily related to new derivative financial instruments used to hedge increased European Euro denominated balance sheet exposures following our acquisition of Paroc. In addition, the Company had notional amounts of $121 million for non-designated derivative financial instruments related to foreign currency exposures in European Euro primarily related to the Russian Ruble, Swedish Krona, and Swiss Franc.

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories consist of the following (in millions): December 31, 2018 2017 Finished goods $ 730 $ 562 Materials and supplies 342 279 Total inventories $ 1,072 $ 841

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2018
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 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. The annual tests performed in 2018 resulted in no impairment of goodwill or indefinite-lived intangible assets. Intangible assets and goodwill consist of the following (in millions): December 31, 2018 Weighted Average Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable intangible assets: Customer relationships 20 years $ 554 $ (138 ) $ 416 Technology 17 years 321 (134 ) 187 Other 14 years 60 (28 ) 32 Indefinite-lived intangible assets: Trademarks 1,144 — 1,144 Total intangible assets $ 2,079 $ (300 ) $ 1,779 Goodwill $ 1,949 December 31, 2017 Weighted Average Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable intangible assets: Customer relationships 20 years $ 363 $ (109 ) $ 254 Technology 18 years 255 (116 ) 139 Other 8 years 47 (26 ) 21 Indefinite-lived intangible assets: Trademarks 946 — 946 Total intangible assets $ 1,611 $ (251 ) $ 1,360 Goodwill $ 1,507 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, 2017 $ 58 1,049 $ 400 $ 1,507 Acquisitions (see Note 8) — 494 — 494 Foreign currency translation (1 ) (48 ) (3 ) (52 ) Balance at December 31, 2018 $ 57 $ 1,495 $ 397 $ 1,949 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. These costs are reported in Other expenses, net on the Consolidated Statements of Earnings. The Other category below primarily includes franchise agreements and emission rights. The changes in the gross carrying amount of intangible assets by asset group are as follows (in millions): Customer Relationships Technology Trademarks Other Total Balance at December 31, 2017 $ 363 $ 255 $ 946 $ 47 $ 1,611 Acquisitions (see Note 8) 215 73 213 7 508 Other additions, net — — — 8 8 Foreign currency translation (24 ) (7 ) (15 ) (2 ) (48 ) Balance at December 31, 2018 $ 554 $ 321 $ 1,144 $ 60 $ 2,079 The estimated amortization expense for intangible assets for the next five years is as follows (in millions): Period Amortization (a) 2019 $ 51 2020 $ 51 2021 $ 50 2022 $ 46 2023 $ 42 (a) The yearly amortization amounts in the table above include approximately $16 million of amortization expense related to the amortizable intangible assets acquired as part of the Paroc acquisition; see Note 8 for more details of this acquisition.

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Land $ 224 $ 251 Buildings and leasehold improvements 1,091 944 Machinery and equipment 4,628 4,211 Construction in progress 443 350 6,386 5,756 Accumulated depreciation (2,575 ) (2,331 ) Property, plant and equipment, net $ 3,811 $ 3,425 Machinery and equipment includes certain precious metals used in our production tooling, which comprise approximately 11% and 12% of total machinery and equipment as of December 31, 2018 and December 31, 2017 , respectively. Precious metals used in our production tooling are depleted as they are consumed during the production process, which typically represents an annual expense of less than 3% of the outstanding carrying value.

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS During 2018, the Company completed acquisitions with an aggregate purchase price of $1,147 million , net of cash acquired. Paroc Acquisition 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, for $1,121 million , net of cash acquired. The acquisition of Paroc expands the Company's mineral wool technology, grows its presence in the European insulation market, provides access to a variety of new end-use markets and will increase the Insulation segment's geographic sales mix outside of the U.S. and Canada. Paroc's operating results and purchase price allocation have been included in the Company’s Insulation segment within the Consolidated Financial Statements. The Company has completed its valuation of certain assets and liabilities, and during 2018, the Company recorded immaterial measurement period adjustments to the purchase price allocation which are reflected in the value of the goodwill noted below. The following table details the identifiable indefinite and definite-lived intangible assets acquired, their fair values (in millions) and estimated weighted average useful lives: Type of Intangible Asset Fair Value Weighted Average Useful Life Customer relationships $ 215 20 Technology - Know-how 61 15 Technology - Patented 12 5 Quarry Rights 7 45 Trademarks 213 Indefinite Total $ 508 During 2018 , the Consolidated Statements of Earnings included $462 million in Net Sales attributable to the acquisition and a $2 million charge related to inventory fair value step-up in Cost of Sales. The acquisition also included property, plant and equipment with a fair value of $305 million and net deferred tax liabilities of $99 million . Goodwill has been valued at $476 million , with none of the amount expected to be tax-deductible. The factors contributing to the recognition of the amount of goodwill are based on several strategic and synergistic benefits that are expected to be realized from the acquisition. The Company has assigned the goodwill acquired to the Insulation reporting unit. The acquisition also included cash of approximately $17 million . The pro forma effect of this acquisition on Net sales and Net earnings attributable to Owens Corning was immaterial. Pittsburgh Corning Acquisition On June 27, 2017, the Company acquired all the outstanding equity of Pittsburgh Corning, the world’s leading producer of cellular glass insulation systems for commercial and industrial markets, for $563 million , net of cash acquired. This acquisition expands the Company’s position in commercial and industrial product offerings and grows its presence in Europe and Asia. Pittsburgh Corning's operating results since the date of acquisition and purchase price allocation have been included in the Company's Insulation segment in the Consolidated Financial Statements. 8. ACQUISITIONS (continued) The following table details the identifiable indefinite and definite-lived intangible assets acquired, their fair values (in millions) and estimated weighted average useful lives: Type of Intangible Asset Fair Value Weighted Average Useful Life Customer relationships $ 107 19 Technology 37 15 Trademarks 101 indefinite Total $ 245 During 2018, the Consolidated Statements of Earnings included $128 million in Net sales attributable to the Pittsburgh Corning acquisition (related to the one-year post-acquisition period). Goodwill has been valued at $154 million , with none of the amount expected to be tax-deductible. The factors contributing to the recognition of the amount of goodwill are based on several strategic and synergistic benefits that are expected to be realized from the acquisition. The acquisition also included cash of approximately $52 million . The pro forma effect of this acquisition on Net sales and Net earnings attributable to Owens Corning was not material.

OPERATING LEASES

OPERATING LEASES	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
OPERATING LEASES	OPERATING LEASES The Company leases certain equipment and facilities under operating leases expiring on various dates through 2032. Some of these leases include cost-escalation clauses. Such cost-escalation clauses are recognized on a straight-line basis over the lease term. Total rental expense was $106 million , $87 million and $79 million in the years ended December 31, 2018 , 2017 and 2016 , respectively. At December 31, 2018 , the minimum future rental commitments under non-cancelable operating leases with initial maturities greater than one year, payable over the remaining lives of the leases are (in millions): Period Minimum Future Rental Commitments 2019 $ 83 2020 $ 64 2021 $ 47 2022 $ 31 2023 $ 18 2024 and beyond $ 27

TOTAL CURRENT LIABILITIES

TOTAL CURRENT LIABILITIES	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
TOTAL CURRENT LIABILITIES	CURRENT LIABILITIES Current liabilities consist of the following current portions of these liabilities (in millions): December 31, 2018 2017 Accounts payable $ 851 $ 834 Payroll, vacation pay and incentive compensation 157 198 Payroll, property and other taxes 43 71 Other 227 179 Total $ 1,278 $ 1,282

WARRANTIES

WARRANTIES	12 Months Ended
	Dec. 31, 2018
Product Warranties Disclosures [Abstract]
WARRANTIES	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, 2018 2017 Beginning balance $ 55 $ 52 Amounts accrued for current year 20 18 Settlements of warranty claims (15 ) (15 ) Ending balance $ 60 $ 55

RESTRUCTURING AND ACQUISITION-R

RESTRUCTURING AND ACQUISITION-RELATED COSTS	12 Months Ended
	Dec. 31, 2018
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. Acquisition-Related Costs During 2018, the Company incurred $16 million of transaction and integration costs related to its announced acquisitions. Please refer to Note 8 of th e Consolidated Financial Statements for further information on these acquisitions. These costs are recorded in the Corporate, Other and Eliminations category. See the Restructuring Costs paragraph below for detail on additional costs related to these acquisitions. The following table presents the impact and respective location of acquisition-related costs for 2018 in the Consolidated Statements of Earnings (in millions): Location Paroc Acquistion Pittsburgh Corning Acquisition Total Marketing and administrative expenses $ 5 $ 2 $ 7 Other expenses, net 9 — 9 Total acquisition-related costs $ 14 $ 2 $ 16 Restructuring Costs Pittsburgh Corning Acquisition-Related Restructuring Following the acquisition of Pittsburgh Corning into the Company's Insulation segment, the Company took actions to realize expected synergies from the newly acquired operations. During 2018, the Company recorded $3 million of charges related to these actions, comprised of $2 million of severance and $1 million of accelerated depreciation. The Company expects to incur an immaterial amount of incremental costs in 2019 related to these actions. 2017 Cost Reduction Actions During the second quarter of 2017, the Company took actions to avoid future capital outlays and reduce costs in its Composites segment, mainly through decisions to close certain sub-scale manufacturing facilities in Asia Pacific (Doudian, People's Republic of China and Thimmapur, India) and North America (Mexico City, Mexico and Brunswick, Maine) and to reposition assets in its Chambery, France operation. During 2018, the Company recorded $19 million of charges, comprised of $2 million of severance, $9 million of accelerated depreciation, and $8 million of exit costs associated with these actions. The Company expects to recognize approximately $8 million of incremental costs in 2019. Consolidated Statements of Earnings Classification The following table presents the impact and respective location of total restructuring costs on the Consolidated Statements of Earnings, which are included in our Corporate, Other and Eliminations category (in millions): Twelve Months Ended December 31, Type of Cost Location 2018 2017 2016 Accelerated depreciation Cost of sales $ 10 $ 17 $ 19 Other exit costs Cost of sales 7 3 6 Severance Other expenses, net 4 27 1 Other exit costs Other expenses, net 1 1 2 Total restructuring costs $ 22 $ 48 $ 28 Summary of Unpaid Liabilities The following table summarizes the status of the unpaid liabilities from the Company’s restructuring activities (in millions): 2017 Cost Reduction Actions Pittsburgh Corning Acquisition-Related Restructuring Total Balance at December 31, 2017 $ 11 $ 9 $ 20 Restructuring costs 19 3 22 Payments (14 ) (4 ) (18 ) Non-cash items and reclassifications to other accounts (6 ) (1 ) (7 ) Balance at December 31, 2018 $ 10 $ 7 $ 17 Cumulative charges incurred $ 48 $ 20 $ 68 As of December 31, 2018 , the remaining liability balance is comprised of $14 million of severance, inclusive of $1 million of non-current severance and $13 million of severance the Company expects to pay over the next twelve months, and $3 million of contract termination fees.

DEBT

DEBT	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value 4.20% senior notes, net of discount and financing fees, due 2022 $ 598 99 % $ 597 105 % 4.20% senior notes, net of discount and financing fees, due 2024 393 99 % 392 105 % 3.40% senior notes, net of discount and financing fees, due 2026 396 90 % 395 98 % 7.00% senior notes, net of discount and financing fees, due 2036 400 112 % 400 132 % 4.30% senior notes, net of discount and financing fees, due 2047 588 76 % 588 99 % 4.40% senior notes, net of discount and financing fees, due 2048 389 77 % — n/a Accounts receivable securitization facility, maturing in 2020 (a) 75 100 % — n/a Various capital leases, due through and beyond 2050 (a) 27 100 % 31 100 % Term loan borrowing, maturing in 2021 (a) 500 100 % — n/a Unamortized interest rate swap basis adjustment 5 n/a 6 n/a Total long-term debt 3,371 n/a 2,409 n/a Less – current portion (a) 9 100 % 4 100 % Long-term debt, net of current portion $ 3,362 n/a $ 2,405 n/a (a) The Company determined that the book value of the above noted 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 $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, 2018 . In the first quarter of 2016, the Company terminated interest rate swaps designated to hedge a portion of the 4.20% senior notes due 2022. The residual fair value of the swaps are recognized in Long-term debt, net of current portion on the Consolidated Balance Sheets as an unamortized interest rate swap basis adjustment. Senior Revolving Credit Facilities The Company has an $800 million Senior Revolving Credit Facility with a maturity date in May 2023. In May 2018, the Company entered into a new agreement to extend its maturity to May 2023 and remove all subsidiaries of the Company as guarantors under the Senior Revolving Credit Facility, unless certain conditions precedent are met that do not exist at this time. The Senior Revolving Credit Facility 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, 2018 . Please refer to the Credit Facility Utilization paragraph below for liquidity information as of December 31, 2018 . Term Loan Commitments The Company obtained two term loan commitments on October 27, 2017 for $300 million and $600 million , respectively, (collectively, the "Term Loan Commitments"). The Company entered into the Term Loan Commitments, 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 $600 million term loan commitment, along with borrowings on the Receivables Securitization Facility and the proceeds of the 2048 senior notes, to fund the purchase of Paroc. The $600 million term loan borrowing (the "Term Loan") requires partial quarterly principal repayments and full repayment by February 2021. On February 12, 2018, the Company voluntarily reduced the entire $300 million term loan commitment, thus eliminating the availability of credit under the facility. On May 4, 2018, the Company amended the terms of the $600 million term loan, among other things, to provide for a reduction in the applicable margin used in the calculation of interest on the outstanding indebtedness and mirror the terms of the new Senior Revolving Credit Facility. As of December 31, 2018 , the Term Loan had $500 million outstanding. The Term Loan Commitment 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. The Company was in compliance with these covenants as of December 31, 2018 . 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 securitization facility (the "Receivables Securitization Facility") has been amended from time to time, with a maturity date of May 2020. The facility was most recently amended in April 2018 to increase the borrowing limit from $250 million to $280 million . No other significant terms impacting liquidity were amended. The Company has the ability to borrow at the lenders' cost of funds, which approximates A-1/P-1 commercial paper rates, plus a fixed spread. 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, 2018 . Please refer to the Credit Facility Utilization section below for liquidity information as of December 31, 2018 . 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): As of December 31, 2018 Senior Revolving Credit Facility Receivables Securitization Facility Facility size $ 800 $ 280 Collateral capacity limitation on availability n/a — Outstanding borrowings — 75 Outstanding letters of credit 9 3 Availability on facility $ 791 $ 202 Debt Maturities The aggregate maturities for all outstanding long-term debt borrowings for each of the five years following December 31, 2018 and thereafter are presented in the table below (in millions). The maturities below are the aggregate par amounts of the outstanding senior notes and borrowings from the Term Loan, Receivables Securitization Facility, and capital lease liabilities: Period Maturities 2019 $ 11 2020 142 2021 441 2022 605 2023 4 2024 and beyond 2,217 Total $ 3,420 Short-Term Debt At December 31, 2018 and December 31, 2017 , short-term borrowings were $16 million and $1 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 -year renewable terms. The weighted average interest rate on all short-term borrowings was approximately 3.0% and 6.7% for December 31, 2018 and December 31, 2017 , respectively.

PENSION PLANS

PENSION PLANS	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
PENSION PLANS	PENSION PLANS ASU 2017-07 Adoption On January 1, 2018, we adopted ASU 2017-07, "Compensation - Retirement Benefits (Topic 715)." This standard requires that the other components of net benefit cost be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. These other components of net benefit cost are now presented in Non-operating (income) expense on the Consolidated Statements of Earnings. In accordance with the standard's retrospective adoption requirement, we used an allowable practical expedient that permits the use of amounts disclosed in previous pension and other postretirement benefit plan disclosures as the estimation basis for applying the retrospective presentation requirement. Accordingly, the amounts below reflect the adoption's combined impact on pension plans (described in this note) and postemployment and postretirement benefits other than pension (described in Note 15). Please refer to the Accounting Pronouncements section of Note 1 for more details on the impact of this adoption. The following tables show the location and impact of the adoption on certain periods in the Consolidated Statements of Earnings: Twelve Months Ended December 31, 2017 Location Before Adoption Adoption Impact After Adoption Cost of sales $ 4,812 $ 3 $ 4,815 Other expenses, net $ 130 $ (63 ) $ 67 Non-operating (income) expense $ — $ 60 $ 60 Twelve Months Ended December 31, 2016 Location Before Adoption Adoption Impact After Adoption Cost of sales $ 4,296 $ 4 $ 4,300 Other expenses, net $ 16 $ (2 ) $ 14 Non-operating (income) expense $ — $ (2 ) $ (2 ) 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 2017, 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 $64 million during the twelve months ended December 31, 2017. These losses are included in Non-operating (income) expense on the Consolidated Statements of Earnings 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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 993 $ 457 $ 1,450 $ 1,066 $ 512 $ 1,578 Service cost 6 6 12 7 5 12 Interest cost 34 13 47 40 15 55 Actuarial loss (gain) (67 ) (18 ) (85 ) 30 (16 ) 14 Currency loss (gain) — (26 ) (26 ) — 42 42 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — 11 11 — 21 21 Other — 7 7 — 12 12 Benefit obligation at end of period $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450 December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Plan Assets Fair value of assets at beginning of period $ 836 $ 364 $ 1,200 $ 822 $ 393 $ 1,215 Actual return on plan assets (59 ) (8 ) (67 ) 114 26 140 Currency gain (loss) — (20 ) (20 ) — 31 31 Company contributions 25 15 40 50 22 72 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — — — — 14 14 Other — — — — 12 12 Fair value of assets at end of period $ 727 $ 328 $ 1,055 $ 836 $ 364 $ 1,200 Funded status $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 ) December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 7 $ 7 $ — $ 7 $ 7 Accrued pension cost – current — (2 ) (2 ) — (1 ) (1 ) Accrued pension cost – non-current (164 ) (104 ) (268 ) (157 ) (99 ) (256 ) Net amount recognized $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 ) Amounts Recorded in AOCI Net actuarial loss $ (392 ) $ (92 ) $ (484 ) $ (357 ) $ (86 ) $ (443 ) 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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with ABO in excess of fair value of plan assets: Projected benefit obligation $ 891 $ 269 $ 1,160 $ 993 $ 288 $ 1,281 Accumulated benefit obligation $ 891 $ 265 $ 1,156 $ 993 $ 284 $ 1,277 Fair value of plan assets $ 727 $ 169 $ 896 $ 836 $ 193 $ 1,029 Plans with fair value of assets in excess of ABO: Projected benefit obligation $ — $ 158 $ 158 $ — $ 169 $ 169 Accumulated benefit obligation $ — $ 140 $ 140 $ — $ 145 $ 145 Fair value of plan assets $ — $ 159 $ 159 $ — $ 171 $ 171 Summary of all plans: Total projected benefit obligation $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450 Total accumulated benefit obligation $ 891 $ 405 $ 1,296 $ 993 $ 429 $ 1,422 Total fair value of plan assets $ 727 $ 328 $ 1,055 $ 836 $ 364 $ 1,200 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, 2018 2017 United States Plans Discount rate 4.25 % 3.55 % Expected return on plan assets 6.75 % 6.75 % Non-United States Plans Discount rate 3.04 % 2.88 % Expected return on plan assets 4.91 % 5.22 % Rate of compensation increase 4.14 % 4.29 % Components of Net Periodic Pension Cost The following table presents the components of net periodic pension cost (in millions): Twelve Months Ended December 31, 2018 2017 2016 Service cost $ 12 $ 12 $ 10 Interest cost 47 55 62 Expected return on plan assets (73 ) (79 ) (81 ) Amortization of actuarial loss 15 18 16 Settlement/curtailment — 64 (6 ) Other — — 2 Net periodic benefit cost $ 1 $ 70 $ 3 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, 2018 2017 2016 United States Plans Discount rate 3.55 % 3.95 % 4.20 % Expected return on plan assets 6.75 % 6.75 % 7.00 % Rate of compensation increase N/A (a) N/A (a) N/A (a) Non-United States Plans Discount rate 2.88 % 3.14 % 3.88 % Expected return on plan assets 5.22 % 5.92 % 6.23 % Rate of compensation increase 4.29 % 4.25 % 3.97 % (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. Accumulated Other Comprehensive Earnings (Deficit) Of the $(484) million balance in AOCI, $14 million is expected to be recognized as net periodic pension cost during 2019 . 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, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 50 $ — $ — $ 50 International 52 — — 52 Fixed income and cash equivalents Corporate bonds — 236 — 236 Government debt — 91 — 91 Real estate investment trusts 24 — — 24 Total United States plan assets subject to leveling $ 126 $ 327 $ — 453 Plan assets measured at NAV Equities 123 Real assets 54 Fixed income and cash equivalents 53 Absolute return strategies 44 Total United States plan assets $ 727 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 67 $ — $ — $ 67 International 78 — — 78 Fixed income and cash equivalents Corporate bonds — 231 — 231 Government debt — 88 — 88 Real estate investment trusts 26 — — 26 Total United States plan assets subject to leveling $ 171 $ 319 $ — 490 Plan assets measured at NAV Equities 173 Real assets 51 Fixed income and cash equivalents 69 Absolute return strategies 53 Total United States plan assets $ 836 The following table summarizes the fair values and applicable fair value hierarchy levels of non-United States pension plan assets (in millions): December 31, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents Cash and cash equivalents — 62 — 62 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 78 $ — 78 Plan assets measured at NAV Equities 41 Fixed income and cash equivalents 109 Absolute return strategies 100 Total non-United States plan assets $ 328 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 3 $ — $ 3 Fixed income and cash equivalents Cash and cash equivalents — 64 — 64 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 79 $ — 79 Plan assets measured at NAV Equities 52 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 364 Investment Strategy The current targeted asset allocation for the United States pension plan is to have 33% of assets invested in equities, 3% in real estate, 8% in real assets, 50% 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 2019 $ 87 2020 $ 85 2021 $ 83 2022 $ 85 2023 $ 83 2024-2028 $ 398 Contributions Owens Corning expects to contribute $25 million in cash to the United States pension plan during 2019 and another $14 million to non-United States plans. 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 , $42 million and $38 million during the years ended December 31, 2018 , 2017 and 2016 , respectively, related to these plans. POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS 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, 2018 and 2017 (in millions): December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 216 $ 14 $ 230 $ 212 $ 13 $ 225 Service cost 1 — 1 2 — 2 Interest cost 8 — 8 8 1 9 Actuarial gain (25 ) — (25 ) (13 ) (2 ) (15 ) Currency loss — (1 ) (1 ) — 1 1 Plan amendments (2 ) — (2 ) (3 ) — (3 ) Benefits paid (15 ) (1 ) (16 ) (12 ) (1 ) (13 ) Acquisition — — — 22 — 22 Other — — — — 2 2 Benefit obligation at end of period $ 183 $ 12 $ 195 $ 216 $ 14 $ 230 Funded status $ (183 ) $ (12 ) $ (195 ) $ (216 ) $ (14 ) $ (230 ) Amounts Recognized in the Consolidated Balance Sheets Accrued benefit obligation – current $ (17 ) $ — $ (17 ) $ (18 ) $ (1 ) $ (19 ) Accrued benefit obligation – non-current (166 ) (12 ) (178 ) (198 ) (13 ) $ (211 ) Net amount recognized $ (183 ) $ (12 ) $ (195 ) $ (216 ) $ (14 ) $ (230 ) Amounts Recorded in AOCI Net actuarial loss (gain) $ (49 ) $ (5 ) $ (54 ) $ (29 ) $ (6 ) $ (35 ) Net prior service cost (credit) (9 ) — (9 ) (12 ) 1 (11 ) Net amount recognized $ (58 ) $ (5 ) $ (63 ) $ (41 ) $ (5 ) $ (46 ) Weighted-Average Assumptions Used to Determine Benefit Obligations The following table presents the discount rates used to determine the benefit obligations: December 31, 2018 2017 United States plans 4.15 % 3.45 % Non-United States plans 4.59 % 4.56 % Components of Net Periodic Postretirement Benefit Cost The following table presents the components of net periodic postretirement benefit cost (in millions): Twelve Months Ended December 31, 2018 2017 2016 Service cost $ 1 $ 2 $ 2 Interest cost 8 9 9 Amortization of prior service cost (4 ) (4 ) (4 ) Amortization of actuarial gain (6 ) (3 ) (1 ) Other — — 1 Net periodic postretirement benefit cost $ (1 ) $ 4 $ 7 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, 2018 2017 2016 United States plans 3.45 % 3.80 % 4.00 % Non-United States plans 4.56 % 6.78 % 3.80 % 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, 2018 2017 2016 United States plans Initial rate at end of year 6.75 % 6.56 % 6.78 % Ultimate rate 5.00 % 5.00 % 5.00 % Year in which ultimate rate is reached 2026 2025 2025 Non-United States plans Initial rate at end of year 5.40 % 5.73 % 5.07 % Ultimate rate 5.40 % 5.49 % 4.70 % Year in which ultimate rate is reached 2019 2019 2019 The health care cost trend rate assumption can have a significant effect on the amounts reported. To illustrate, a one-percentage point change in the December 31, 2018 assumed health care cost trend rate would have the following effects (in millions): 1-Percentage Point Increase Decrease Increase (decrease) in total service cost and interest cost components of net periodic postretirement benefit cost $ — $ — Increase (decrease) of accumulated postretirement benefit obligation $ 4 $ (3 ) Accumulated Other Comprehensive Earnings (Deficit) Approximately $12 million of the $63 million balance in AOCI is expected to be recognized as net periodic postretirement benefit during 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 2019 $ 18 2020 $ 18 2021 $ 17 2022 $ 17 2023 $ 16 2024-2028 $ 70 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, 2018 and 2017 was $12 million and $13 million , respectively. The net periodic postemployment benefit expense was $4 million for the year ended December 31, 2018 , $3 million in 2017 , and $2 million in 2016 .

POSTEMPLOYMENT AND POSTRETIREME

POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS	PENSION PLANS ASU 2017-07 Adoption On January 1, 2018, we adopted ASU 2017-07, "Compensation - Retirement Benefits (Topic 715)." This standard requires that the other components of net benefit cost be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. These other components of net benefit cost are now presented in Non-operating (income) expense on the Consolidated Statements of Earnings. In accordance with the standard's retrospective adoption requirement, we used an allowable practical expedient that permits the use of amounts disclosed in previous pension and other postretirement benefit plan disclosures as the estimation basis for applying the retrospective presentation requirement. Accordingly, the amounts below reflect the adoption's combined impact on pension plans (described in this note) and postemployment and postretirement benefits other than pension (described in Note 15). Please refer to the Accounting Pronouncements section of Note 1 for more details on the impact of this adoption. The following tables show the location and impact of the adoption on certain periods in the Consolidated Statements of Earnings: Twelve Months Ended December 31, 2017 Location Before Adoption Adoption Impact After Adoption Cost of sales $ 4,812 $ 3 $ 4,815 Other expenses, net $ 130 $ (63 ) $ 67 Non-operating (income) expense $ — $ 60 $ 60 Twelve Months Ended December 31, 2016 Location Before Adoption Adoption Impact After Adoption Cost of sales $ 4,296 $ 4 $ 4,300 Other expenses, net $ 16 $ (2 ) $ 14 Non-operating (income) expense $ — $ (2 ) $ (2 ) 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 2017, 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 $64 million during the twelve months ended December 31, 2017. These losses are included in Non-operating (income) expense on the Consolidated Statements of Earnings 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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 993 $ 457 $ 1,450 $ 1,066 $ 512 $ 1,578 Service cost 6 6 12 7 5 12 Interest cost 34 13 47 40 15 55 Actuarial loss (gain) (67 ) (18 ) (85 ) 30 (16 ) 14 Currency loss (gain) — (26 ) (26 ) — 42 42 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — 11 11 — 21 21 Other — 7 7 — 12 12 Benefit obligation at end of period $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450 December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Plan Assets Fair value of assets at beginning of period $ 836 $ 364 $ 1,200 $ 822 $ 393 $ 1,215 Actual return on plan assets (59 ) (8 ) (67 ) 114 26 140 Currency gain (loss) — (20 ) (20 ) — 31 31 Company contributions 25 15 40 50 22 72 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — — — — 14 14 Other — — — — 12 12 Fair value of assets at end of period $ 727 $ 328 $ 1,055 $ 836 $ 364 $ 1,200 Funded status $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 ) December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 7 $ 7 $ — $ 7 $ 7 Accrued pension cost – current — (2 ) (2 ) — (1 ) (1 ) Accrued pension cost – non-current (164 ) (104 ) (268 ) (157 ) (99 ) (256 ) Net amount recognized $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 ) Amounts Recorded in AOCI Net actuarial loss $ (392 ) $ (92 ) $ (484 ) $ (357 ) $ (86 ) $ (443 ) 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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with ABO in excess of fair value of plan assets: Projected benefit obligation $ 891 $ 269 $ 1,160 $ 993 $ 288 $ 1,281 Accumulated benefit obligation $ 891 $ 265 $ 1,156 $ 993 $ 284 $ 1,277 Fair value of plan assets $ 727 $ 169 $ 896 $ 836 $ 193 $ 1,029 Plans with fair value of assets in excess of ABO: Projected benefit obligation $ — $ 158 $ 158 $ — $ 169 $ 169 Accumulated benefit obligation $ — $ 140 $ 140 $ — $ 145 $ 145 Fair value of plan assets $ — $ 159 $ 159 $ — $ 171 $ 171 Summary of all plans: Total projected benefit obligation $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450 Total accumulated benefit obligation $ 891 $ 405 $ 1,296 $ 993 $ 429 $ 1,422 Total fair value of plan assets $ 727 $ 328 $ 1,055 $ 836 $ 364 $ 1,200 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, 2018 2017 United States Plans Discount rate 4.25 % 3.55 % Expected return on plan assets 6.75 % 6.75 % Non-United States Plans Discount rate 3.04 % 2.88 % Expected return on plan assets 4.91 % 5.22 % Rate of compensation increase 4.14 % 4.29 % Components of Net Periodic Pension Cost The following table presents the components of net periodic pension cost (in millions): Twelve Months Ended December 31, 2018 2017 2016 Service cost $ 12 $ 12 $ 10 Interest cost 47 55 62 Expected return on plan assets (73 ) (79 ) (81 ) Amortization of actuarial loss 15 18 16 Settlement/curtailment — 64 (6 ) Other — — 2 Net periodic benefit cost $ 1 $ 70 $ 3 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, 2018 2017 2016 United States Plans Discount rate 3.55 % 3.95 % 4.20 % Expected return on plan assets 6.75 % 6.75 % 7.00 % Rate of compensation increase N/A (a) N/A (a) N/A (a) Non-United States Plans Discount rate 2.88 % 3.14 % 3.88 % Expected return on plan assets 5.22 % 5.92 % 6.23 % Rate of compensation increase 4.29 % 4.25 % 3.97 % (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. Accumulated Other Comprehensive Earnings (Deficit) Of the $(484) million balance in AOCI, $14 million is expected to be recognized as net periodic pension cost during 2019 . 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, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 50 $ — $ — $ 50 International 52 — — 52 Fixed income and cash equivalents Corporate bonds — 236 — 236 Government debt — 91 — 91 Real estate investment trusts 24 — — 24 Total United States plan assets subject to leveling $ 126 $ 327 $ — 453 Plan assets measured at NAV Equities 123 Real assets 54 Fixed income and cash equivalents 53 Absolute return strategies 44 Total United States plan assets $ 727 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 67 $ — $ — $ 67 International 78 — — 78 Fixed income and cash equivalents Corporate bonds — 231 — 231 Government debt — 88 — 88 Real estate investment trusts 26 — — 26 Total United States plan assets subject to leveling $ 171 $ 319 $ — 490 Plan assets measured at NAV Equities 173 Real assets 51 Fixed income and cash equivalents 69 Absolute return strategies 53 Total United States plan assets $ 836 The following table summarizes the fair values and applicable fair value hierarchy levels of non-United States pension plan assets (in millions): December 31, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents Cash and cash equivalents — 62 — 62 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 78 $ — 78 Plan assets measured at NAV Equities 41 Fixed income and cash equivalents 109 Absolute return strategies 100 Total non-United States plan assets $ 328 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 3 $ — $ 3 Fixed income and cash equivalents Cash and cash equivalents — 64 — 64 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 79 $ — 79 Plan assets measured at NAV Equities 52 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 364 Investment Strategy The current targeted asset allocation for the United States pension plan is to have 33% of assets invested in equities, 3% in real estate, 8% in real assets, 50% 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 2019 $ 87 2020 $ 85 2021 $ 83 2022 $ 85 2023 $ 83 2024-2028 $ 398 Contributions Owens Corning expects to contribute $25 million in cash to the United States pension plan during 2019 and another $14 million to non-United States plans. 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 , $42 million and $38 million during the years ended December 31, 2018 , 2017 and 2016 , respectively, related to these plans. POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS 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, 2018 and 2017 (in millions): December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 216 $ 14 $ 230 $ 212 $ 13 $ 225 Service cost 1 — 1 2 — 2 Interest cost 8 — 8 8 1 9 Actuarial gain (25 ) — (25 ) (13 ) (2 ) (15 ) Currency loss — (1 ) (1 ) — 1 1 Plan amendments (2 ) — (2 ) (3 ) — (3 ) Benefits paid (15 ) (1 ) (16 ) (12 ) (1 ) (13 ) Acquisition — — — 22 — 22 Other — — — — 2 2 Benefit obligation at end of period $ 183 $ 12 $ 195 $ 216 $ 14 $ 230 Funded status $ (183 ) $ (12 ) $ (195 ) $ (216 ) $ (14 ) $ (230 ) Amounts Recognized in the Consolidated Balance Sheets Accrued benefit obligation – current $ (17 ) $ — $ (17 ) $ (18 ) $ (1 ) $ (19 ) Accrued benefit obligation – non-current (166 ) (12 ) (178 ) (198 ) (13 ) $ (211 ) Net amount recognized $ (183 ) $ (12 ) $ (195 ) $ (216 ) $ (14 ) $ (230 ) Amounts Recorded in AOCI Net actuarial loss (gain) $ (49 ) $ (5 ) $ (54 ) $ (29 ) $ (6 ) $ (35 ) Net prior service cost (credit) (9 ) — (9 ) (12 ) 1 (11 ) Net amount recognized $ (58 ) $ (5 ) $ (63 ) $ (41 ) $ (5 ) $ (46 ) Weighted-Average Assumptions Used to Determine Benefit Obligations The following table presents the discount rates used to determine the benefit obligations: December 31, 2018 2017 United States plans 4.15 % 3.45 % Non-United States plans 4.59 % 4.56 % Components of Net Periodic Postretirement Benefit Cost The following table presents the components of net periodic postretirement benefit cost (in millions): Twelve Months Ended December 31, 2018 2017 2016 Service cost $ 1 $ 2 $ 2 Interest cost 8 9 9 Amortization of prior service cost (4 ) (4 ) (4 ) Amortization of actuarial gain (6 ) (3 ) (1 ) Other — — 1 Net periodic postretirement benefit cost $ (1 ) $ 4 $ 7 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, 2018 2017 2016 United States plans 3.45 % 3.80 % 4.00 % Non-United States plans 4.56 % 6.78 % 3.80 % 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, 2018 2017 2016 United States plans Initial rate at end of year 6.75 % 6.56 % 6.78 % Ultimate rate 5.00 % 5.00 % 5.00 % Year in which ultimate rate is reached 2026 2025 2025 Non-United States plans Initial rate at end of year 5.40 % 5.73 % 5.07 % Ultimate rate 5.40 % 5.49 % 4.70 % Year in which ultimate rate is reached 2019 2019 2019 The health care cost trend rate assumption can have a significant effect on the amounts reported. To illustrate, a one-percentage point change in the December 31, 2018 assumed health care cost trend rate would have the following effects (in millions): 1-Percentage Point Increase Decrease Increase (decrease) in total service cost and interest cost components of net periodic postretirement benefit cost $ — $ — Increase (decrease) of accumulated postretirement benefit obligation $ 4 $ (3 ) Accumulated Other Comprehensive Earnings (Deficit) Approximately $12 million of the $63 million balance in AOCI is expected to be recognized as net periodic postretirement benefit during 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 2019 $ 18 2020 $ 18 2021 $ 17 2022 $ 17 2023 $ 16 2024-2028 $ 70 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, 2018 and 2017 was $12 million and $13 million , respectively. The net periodic postemployment benefit expense was $4 million for the year ended December 31, 2018 , $3 million in 2017 , and $2 million in 2016 .

CONTINGENT LIABILITIES AND OTHE

CONTINGENT LIABILITIES AND OTHER MATTERS	12 Months Ended
	Dec. 31, 2018
Loss Contingency [Abstract]
CONTINGENT LIABILITIES AND OTHER MATTERS	CONTINGENT LIABILITIES AND OTHER MATTERS The Company may be involved in various legal and regulatory proceedings relating to employment, antitrust, tax, product liability, environmental 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. Litigation Settlement Gain In 2017, the Company and TopBuild Corp. entered into a settlement agreement in connection with a commercial breach of contract dispute. Under the terms of the settlement, TopBuild Corp. paid Owens Corning $30 million in cash in 2017. During the second quarter of 2017, a $29 million litigation settlement gain, net of legal fees, was recorded in Other expenses, net on the Consolidated Statements of Earnings in the Corporate, Other and Eliminations category. 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, discharges to water, management of hazardous materials, handling and disposal of solid wastes, and remediation of contaminated sites. All Company manufacturing facilities operate using an ISO 14001 or equivalent environmental management system. The Company’s 2020 Sustainability Goals require significant global reductions in energy use, water consumption, waste to landfill, emissions of greenhouse gases, fine particulate matter and toxic air emissions.The Company is dedicated to continuous improvement in our environmental, health and safety performance and to achieving its 2020 Sustainability Goals. Owens Corning is involved in remedial response activities and is responsible for environmental remediation at a number of sites, including certain of its currently owned or formerly owned plants. These responsibilities arise under a number of laws, including, but not limited to, the Federal Resource Conservation and Recovery Act, and similar state or local laws pertaining to the management and remediation of hazardous materials and petroleum. The Company has also been named a potentially responsible party under the U.S. Federal Superfund law, or state equivalents, at a number of disposal sites. The Company became involved in these sites as a result of government action or in connection with business acquisitions. As of December 31, 2018 , the Company was involved with a total of 22 sites worldwide, including 8 Superfund sites and 14 owned or formerly owned sites. None of the liabilities for these sites are individually significant to the Company. Remediation activities generally involve a potential range of activities and costs related to soil and groundwater contamination. This can include pre-cleanup activities such as fact finding and investigation, risk assessment, feasibility studies, remedial action design and implementation (where actions may range from monitoring to removal of contaminants, to installation of longer-term remediation systems). A number of factors affect the cost of environmental remediation, including the number of parties involved in a particular site, the determination of the extent of contamination, the length of time the remediation may require, the complexity of environmental regulations, variability in clean-up standards, the need for legal action, and changes in remediation technology. Taking these factors into account, Owens Corning has predicted the costs of remediation reasonably estimated to be paid over a period of years. The Company accrues an amount on an undiscounted basis, consistent with the reasonable estimates of these costs when it is probable that a liability has been incurred. Actual cost may differ from these estimates for the reasons mentioned above. At December 31, 2018 , the Company had an accrual totaling $16 million for its environmental liabilities, of which the current portion is $8 million . Changes in required remediation procedures or timing of those procedures, or discovery of contamination at additional sites, could result in material increases to the Company’s environmental obligations.

STOCK COMPENSATION

STOCK COMPENSATION	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK COMPENSATION	STOCK COMPENSATION 2016 Stock Plan On April 21, 2016, the Company's stockholders approved the Owens Corning 2016 Stock Plan (the "2016 Stock Plan") which replaced the 2013 Stock Plan. The 2016 Stock Plan authorizes grants of stock options, stock appreciation rights, restricted stock awards, restricted stock units, bonus stock awards and performance stock awards. At December 31, 2018 , the number of shares remaining available under the 2016 Stock Plan for all stock awards was 2.5 million . 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 year vesting period. In general, the exercise price of each option awarded was equal to the closing market price of the Company’s common stock on the date of grant and an option’s maximum term is 10 years. The volatility assumption was based on a benchmark study of our peers prior to 2014. Starting with the options granted in 2014, the volatility was based on the Company’s historic volatility. During 2018, 2017 and 2016, no stock options were granted. During the years ended December 31, 2018 , 2017 and 2016 , the Company recognized expense of less than $1 million , $1 million and $2 million , respectively, related to the Company’s stock options. As of December 31, 2018 , there was no unrecognized compensation cost related to stock options. The total aggregate intrinsic value of options outstanding as of December 31, 2018 , 2017 and 2016 was $3 million , $28 million and $16 million , respectively. The total aggregate intrinsic value of options exercisable as of December 31, 2018 , 2017 and 2016 was $3 million , $25 million and $13 million , respectively. Cash received from option exercises was $1 million , $15 million and $26 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. There were no tax benefits realized from tax deductions associated with option exercises for the year ended December 31, 2018 . Tax benefits realized from tax deductions associated with option exercises totaled $7 million and $9 million for the years ended December 31, 2017 and 2016 , respectively. The following table summarizes the Company’s stock option activity: Twelve Months Ended December 31, 2018 2017 2016 Number of Options Weighted- Average Exercise Price Number of Options Weighted- Average Exercise Price Number of Options Weighted- Average Exercise Price Beginning Balance 518,725 $ 37.17 975,400 $ 35.14 1,953,320 $ 31.09 Granted — — — — — — Exercised (39,100 ) 37.05 (453,425 ) 32.79 (960,570 ) 26.90 Forfeited (750 ) 37.65 (3,250 ) 37.65 (11,350 ) 38.50 Expired — — — — (6,000 ) 30.00 Ending Balance 478,875 $ 37.18 518,725 $ 37.17 975,400 $ 35.14 The following table summarizes information about the Company’s options outstanding and exercisable: Options Outstanding Options Exercisable Weighted-Average Number Exercisable at Dec. 31, 2018 Weighted-Average Range of Exercise Prices Options Outstanding Remaining Contractual Life Exercise Price Remaining Contractual Life Exercise Price $13.89 - $42.16 478,875 4.00 $ 37.18 478,875 4.00 $ 37.18 Restricted Stock Awards and Restricted Stock Units The Company has granted restricted stock awards and restricted stock units (collectively referred to as “restricted stock”) 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 years. The Stock Plan allows alternate vesting schedules for death, disability, and retirement over various periods ending in 2020. During the years ended December 31, 2018 , 2017 and 2016 , the Company recognized expense of $23 million , $21 million and $19 million , respectively, related to the Company’s restricted stock. As of December 31, 2018 , there was $36 million of total unrecognized compensation cost related to restricted stock. That cost is expected to be recognized over a weighted-average period of 2.40 years. The total grant date fair value of shares vested during the years ended December 31, 2018 , 2017 and 2016 , was $23 million , $19 million and $15 million , respectively. The following table shows a summary of the Company’s Restricted Stock plans: Twelve Months Ended December 31, 2018 2017 2016 Number of Shares Weighted- Average Grant Date Fair Value Number of Shares Weighted- Average Grant Date Fair Value Number of Shares Weighted- Average Grant Date Fair Value Beginning Balance 1,752,136 $ 42.40 1,800,557 $ 37.78 1,707,490 $ 35.37 Granted 365,363 84.34 496,021 56.60 544,627 45.61 Vested (558,288 ) 41.34 (477,857 ) 38.94 (398,751 ) 37.55 Forfeited (79,837 ) 54.20 (66,585 ) 44.90 (52,809 ) 39.80 Ending Balance 1,479,374 $ 52.30 1,752,136 $ 42.40 1,800,557 $ 37.78 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 2018, 2017 and 2016 grants is contingent on meeting internal company-based metrics or an external-based stock performance metric. In 2018, 2017 and 2016, 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 -year period. The amount of stock distributed will vary from 0% to 300% of PSUs awarded depending on performance versus the company-based metrics. 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 -year period. Outstanding grants issued in or after 2015 will be based on the Company's total stockholder return relative to the performance of the S&P Building & Construction Industry Index. The amount of stock distributed will vary from 0% to 200% of PSUs awarded depending on the relative stockholder return performance. 2018 Grant For the 2018 grant, the fair value of the external based metric PSUs was estimated at the grant date using a Monte Carlo simulation that used various assumptions that include expected volatility of 24.56% , a risk free interest rate of 2.22% and an expected term of 2.92 years. Expected volatility was based on Owens Corning's most recent 2.92 years volatility. 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. For the 2018 grant, the fair value of the internal based metric PSUs was estimated using the grant date stock price and assumed that the performance goals will be achieved. This assumption is monitored each quarter and if it becomes probable that such goals will not be achieved or will be exceeded, compensation expense recognized will be adjusted. This adjustment results in either reversing previous surplus compensation expense recognized or recognizing additional expense. 2017 Grant For the 2017 grant, the fair value of the external based metric PSUs was estimated at the grant date using a Monte Carlo simulation that used various assumptions that include expected volatility of 26.06% , a risk free interest rate of 1.44% and an expected term of 2.92 years. Expected volatility was based on Owens Corning's most recent 2.92 years volatility. 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. For the 2017 grant, the fair value of the internal based metric PSUs was estimated using the grant date stock price and assumed that the performance goals will be achieved. This assumption is monitored each quarter and if it becomes probable that such goals will not be achieved or will be exceeded, compensation expense recognized will be adjusted. This adjustment results in either reversing previous surplus compensation expense recognized or recognizing additional expense. 2016 Grant For the 2016 grant, the fair value of the external based metric PSUs was estimated at the grant date using a Monte Carlo simulation that used various assumptions that include expected volatility of 26.55% , a risk free interest rate of 0.84% and an expected term of 2.91 years. Expected volatility was based on Owens Corning's most recent 2.91 years volatility. 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. For the 2016 grant, the fair value of the internal based metric PSUs was estimated using the grant date stock price and assumed that the performance goals will be achieved. The performance period for this grant ended in 2018, and performance was consistent with estimated compensation expense that was recognized over the life of the grant. PSU Summary For all PSUs, respectively, during the years ended December 31, 2018 , 2017 and 2016 , the Company recognized expense of $20 million , $19 million and $16 million . As of December 31, 2018 , there was $14 million total unrecognized compensation cost related to PSUs. That cost is expected to be recognized over a weighted-average period of 1.57 years. The total grant date fair value of shares vested during the years ended December 31, 2018 , 2017 and 2016 , was $23 million , $9 million and $3 million , respectively. The following table shows a summary of the Company's PSU plans: Twelve Months Ended December 31, 2018 2017 2016 Number of PSUs Weighted- Average Grant Date Fair Value Number of PSUs Weighted- Average Grant Date Fair Value Number of PSUs Weighted- Average Grant Date Fair Value Beginning Balance 451,148 $ 53.96 472,300 $ 47.19 431,400 $ 44.52 Granted 171,725 94.14 221,050 59.71 244,250 48.74 Vested (212,852 ) 48.73 (219,050 ) 43.83 (186,750 ) 44.43 Forfeited/canceled (49,044 ) 60.31 (23,152 ) 49.50 (16,600 ) 44.48 Ending Balance 360,977 $ 75.23 451,148 $ 53.96 472,300 $ 47.19 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. There were 2 million shares available for purchase under the ESPP as of its approval date. The Company recognized expense related to the ESPP of $4 million , $3 million and $3 million for the years ended December 31, 2018 , 2017 and 2016, respectively. As of December 31, 2018 , the Company had $2 million of total unrecognized compensation costs related to the ESPP. For the years ended December 31, 2018 , 2017 and 2016, our employees purchased 0.3 million shares at an average price of $48.93 , 0.3 million shares at an average price of $48.48 , and 0.2 million shares at an average price of $41.99 , respectively. Under the outstanding ESPP as of February 15, 201 9 employees have contributed $4 million to purchase shares for the current purchase period ending May 31, 2019.

CHANGES IN ACCUMULATED OTHER CO

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT	12 Months Ended
	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT	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, 2018 2017 Currency Translation Adjustment Beginning balance $ (183 ) $ (284 ) Net investment hedge amounts classified into AOCI, net of tax 14 (24 ) (Loss) Gain on foreign currency translation (137 ) 125 Other comprehensive (loss)/income, net of tax (123 ) 101 Ending balance $ (306 ) $ (183 ) Pension and Other Postretirement Adjustment Beginning balance $ (331 ) $ (429 ) Amounts reclassified from AOCI to net earnings, net of tax (a) 4 53 Amounts classified into AOCI, net of tax (23 ) 45 Other comprehensive (loss)/income, net of tax (19 ) 98 Ending balance $ (350 ) $ (331 ) Hedging Adjustment Beginning balance $ — $ 3 Amounts reclassified from AOCI to net earnings, net of tax (b) (1 ) (1 ) Amounts classified into AOCI, net of tax 1 (2 ) Other comprehensive (loss), net of tax — (3 ) Ending balance $ — $ — Total AOCI ending balance $ (656 ) $ (514 ) (a) These AOCI components are included in the computation of total Pension and OPEB expense and are recorded in Cost of sales, marketing and administrative expenses and Other expenses, net. See Notes 14 and 15 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. See Note 5 for additional information.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The following table is a reconciliation of weighted-average shares for calculating basic and diluted earnings per-share (in millions, except per share amounts): Twelve Months Ended December 31, 2018 2017 2016 Net earnings attributable to Owens Corning $ 545 $ 289 $ 393 Weighted-average number of shares outstanding used for basic earnings per share 110.4 111.5 114.4 Non-vested restricted and performance shares 0.8 1.5 0.8 Options to purchase common stock 0.2 0.2 0.2 Weighted-average number of shares outstanding and common equivalent shares used for diluted earnings per share 111.4 113.2 115.4 Earnings per common share attributable to Owens Corning common stockholders: Basic $ 4.94 $ 2.59 $ 3.44 Diluted $ 4.89 $ 2.55 $ 3.41 Basic earnings per share is calculated by dividing earnings 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 October 24, 2016, 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 “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 2.9 million shares of its common stock for $203 million for the year ended December 31, 2018 under the Repurchase Authorization. As of December 31, 2018, 4.6 million shares remain available for repurchase under the Repurchase Authorization. For the year ended December 31, 2018, the number of shares used in the calculation of diluted earnings per share did not include 0.3 million non-vested restricted shares and 0.3 million non-vested performance shares, due to their anti-dilutive effect. For the year ended December 31, 2017, we did not have any non-vested restricted shares or non-vested performance shares that had an anti-dilutive effect on earnings per share. For the years ended December 31, 2016, the number of shares used in the calculation of diluted earnings per share did not include 0.1 million non-vested performance shares, due to their anti-dilutive effect.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The following table summarizes our Earnings before taxes and Income tax expense (in millions): Twelve Months Ended December 31, 2018 2017 2016 Earnings before taxes: United States $ 411 $ 342 $ 281 Foreign 293 217 309 Total $ 704 $ 559 $ 590 Income tax expense: Current United States $ (10 ) $ (2 ) $ (7 ) State and local 6 5 4 Foreign 19 83 55 Total current 15 86 52 Deferred United States 114 196 117 State and local 12 3 8 Foreign 15 (16 ) 11 Total deferred 141 183 136 Total income tax expense $ 156 $ 269 $ 188 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, 2018 2017 2016 United States federal statutory rate 21 % 35 % 35 % State and local income taxes, net of federal tax benefit 2 2 2 Foreign tax rate differential — (5 ) (4 ) U.S. tax expense on foreign earnings 2 49 2 Legislative tax rate changes — (9 ) 1 Foreign tax credits — (29 ) — Valuation allowance 2 3 (3 ) Uncertain tax positions and settlements (5 ) 1 1 Excess tax benefits related to stock compensation (2 ) (1 ) (1 ) Other, net 2 2 (1 ) Effective tax rate 22 % 48 % 32 % During the first quarter of 2018, the Company adopted ASU No. 2016-16, “Intra-Entity Transfers of Assets Other Than Inventory (Topic 740).” Under this standard, the tax effects of intra-entity sales of assets other than inventory will be recognized immediately in the seller's tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. Any deferred tax asset that arises in the buyer’s jurisdiction would also be recognized at the time of the transfer. The standard is applied using a modified retrospective transition method by means of a cumulative-effect adjustment to equity as of the beginning of the year of adoption. As of January 1, 2018, we recorded a $17 million decrease in Other non-current assets, a $7 million increase in Deferred income tax assets and a $10 million decrease to Accumulated earnings. The U.S. government enacted tax legislation commonly known as the U.S. Tax Cuts and Jobs Act of 2017 on December 22, 2017 (the "Tax Act"). The Tax Act made broad and complex changes to the U.S. tax code, including but not limited to, a reduction to the U.S. federal corporate income tax rate from 35% to 21%; a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries (the "Transition Tax”); eliminating the corporate alternative minimum tax (AMT) and changing realization of AMT credits; changing rules related to uses and limitations of net operating loss (NOL) carryforwards created in tax years after December 31, 2017; changes to the limitations on available interest expense deductions; and changes to other existing deductions and business-related exclusions The SEC issued Staff Accounting Bulletin No. 118, "Income Tax Accounting Implications of the Tax Cuts and Jobs Act" ("SAB 118"), which provides guidance on the accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date to complete the accounting under ASC 740, "Income Taxes." In accordance with SAB 118, a provisional non-cash charge of $82 million was recorded to tax expense in December 2017 based on reasonable estimates of certain effects of the Tax Act. During the measurement period, the Company completed the accounting for income tax effects of the Tax Act, which resulted in an increase to the provisional charge of $9 million . Effective January 1, 2018, the Tax Act creates a new requirement to include in U.S. income global intangible low-taxed income (GILTI) earned by controlled foreign corporations (CFCs). 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. 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, 2018, the Company has not provided for withholding or income taxes on approximately $1.4 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, 2018 December 31, 2017 Deferred Tax Assets Deferred Tax Liabilities Deferred Tax Assets Deferred Tax Liabilities Other employee benefits $ 87 $ — $ 92 $ — Pension plans 66 — 48 — Operating loss and tax credit carryforwards 255 — 377 — Depreciation — 259 — 234 Amortization — 395 — 314 Foreign tax credits 161 — 160 — State and local taxes 3 — 3 — Other 61 — 69 — Subtotal 633 654 749 548 Valuation allowances (78 ) — (94 ) — Total deferred taxes $ 555 $ 654 $ 655 $ 548 The following table summarizes the amount and expiration dates of our deferred tax assets related to operating loss and credit carryforwards at December 31, 2018 (in millions): Expiration Dates Amounts U.S. federal loss carryforwards 2027 – 2032 $ 65 U.S. state loss carryforwards (a) 2019 – 2034 58 Foreign loss and tax credit carryforwards Indefinite 37 Foreign loss and tax credit carryforwards (a) 2019 – 2034 65 Other U.S. federal and state tax credits 2028 – 2034 30 Total operating loss and tax credit carryforwards $ 255 U.S foreign tax credits 2027 $ 161 (a) As of December 31, 2018 , $8 million of U.S. state and $6 million of foreign deferred tax assets related to loss carryforwards are set to expire over the next three years . At December 31, 2018 , the Company had federal, state and foreign net operating loss (NOL) carryforwards of $0.4 billion , $1.6 billion and $0.4 billion , respectively. In order to utilize our NOLs and U.S. foreign tax credits ("FTCs"), the Company will need to generate federal, state, and foreign earnings before taxes of approximately $1.3 billion , $1.9 billion , and $0.4 billion , respectively. Certain of these loss carryforwards are subject to limitation as a result of the changes of control that resulted from the Company’s emergence from bankruptcy in 2006 and 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. On June 27, 2017, the Company acquired all the outstanding equity of Pittsburgh Corning. On the date of acquisition, Pittsburgh Corning's tax attributes included a $296 million NOL carryover generated during the tax year 2016 and short tax year ending June 27, 2017. Section 382 of the Internal Revenue Code (IRC) limits the use of net operating loss tax attributes when a corporation experiences an "ownership change." The acquisition of Pittsburgh Corning on June 27, 2017 qualifies as an "ownership change" under IRC Section 382 which limits the ability to use pre-ownership change losses to offset post-ownership change taxable income. The limits imposed under IRC Section 382 allows utilization of $192 million of Pittsburgh Corning’s NOLs and is included in the Company’s total federal NOLs recorded as of December 31, 2017. 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, 2018 , the Company had federal and state net deferred tax assets before valuation allowances of $11 million and $18 million , and foreign net deferred tax liabilities of $50 million . The valuation allowance of $78 million as of December 31, 2018 is related to tax assets of $34 million , $6 million and $38 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 $1 million . The valuation allowance of $94 million as of December 31, 2017 is related to tax assets of $24 million , $1 million , and $69 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 2013 or state and foreign examinations for years before 2008. 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 $3 million . A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in millions): Twelve Months Ended December 31, 2018 2017 2016 Balance at beginning of period $ 90 $ 98 $ 84 Tax positions related to the current year Gross additions 6 1 1 Tax positions related to prior years Gross additions 36 13 19 Gross reductions (37 ) (11 ) (5 ) Settlements (5 ) (12 ) (1 ) Expiration of statute of limitations (4 ) — — Impact of currency changes (2 ) 1 — Balance at end of period $ 84 $ 90 $ 98 If these uncertain tax benefits (UTBs) were to be recognized as of December 31, 2018 , the Company’s income tax expense would decrease by about $65 million . The Company classifies all interest and penalties as income tax expense. As of December 31, 2018 , 2017 and 2016 , and for the periods then ended, the Company recognized $10 million , $11 million and $11 million respectively, in liabilities for tax related interest and penalties on its Consolidated Balance Sheets and $1 million , $1 million and $(1) million , respectively, of interest and penalty expense (income) on its Consolidated Statements of Earnings. 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 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.

QUARTERLY FINANCIAL INFORMATION

QUARTERLY FINANCIAL INFORMATION (unaudited)	12 Months Ended
	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
QUARTERLY FINANCIAL INFORMATION (unaudited)	QUARTERLY FINANCIAL INFORMATION (unaudited) Select quarterly financial information is presented in the tables below for the quarterly periods (in millions, except per share amounts): Quarter First Second Third Fourth 2018 Net sales $ 1,691 $ 1,824 $ 1,818 $ 1,724 Gross margin $ 355 $ 418 $ 448 $ 411 Income tax expense $ 11 $ 49 $ 67 $ 29 Net earnings attributable to Owens Corning $ 92 $ 121 $ 161 $ 171 BASIC EARNINGS PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.83 $ 1.09 $ 1.46 $ 1.56 DILUTED EARNINGS PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.82 $ 1.08 $ 1.45 $ 1.55 Quarter First Second Third Fourth 2017 Net sales $ 1,478 $ 1,597 $ 1,703 $ 1,606 Gross margin (a) $ 342 $ 408 $ 423 $ 396 Income tax expense (b) $ 43 $ 67 $ 32 $ 127 Net earnings (loss) attributable to Owens Corning $ 101 $ 96 $ 96 $ (4 ) BASIC EARNINGS (LOSS) PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.90 $ 0.86 $ 0.86 $ (0.04 ) DILUTED EARNINGS (LOSS) PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.89 $ 0.85 $ 0.85 $ (0.04 ) (a) Gross margin was impacted by the retrospective adoption of ASU 2017-07, which resulted in a gross margin decrease of $1 million for the first, second and third quarters of 2017. See Note 14 for more information on this adoption. (b) Income tax expense for the fourth quarter of 2017 includes a provisional charge of $82 million related to the Tax Act. Please refer to Note 20 for additional details on this charge.

SCHEDULE II - VALUATION AND QUA

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (NOTE)	12 Months Ended
	Dec. 31, 2018
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, 2018, 2017 AND 2016 (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, 2018 Allowance for doubtful accounts $ 19 $ — $ — $ (4 ) (a) $ 1 $ 16 Tax valuation allowance $ 94 $ 13 $ (4 ) $ (31 ) $ 6 $ 78 FOR THE YEAR ENDED DECEMBER 31, 2017 Allowance for doubtful accounts $ 9 $ 12 $ — $ (2 ) (a) $ — $ 19 Tax valuation allowance $ 103 $ 9 $ 7 $ (25 ) $ — $ 94 FOR THE YEAR ENDED DECEMBER 31, 2016 Allowance for doubtful accounts $ 8 $ 2 $ — $ (1 ) (a) $ — $ 9 Tax valuation allowance $ 135 $ (27 ) $ (5 ) $ — $ — $ 103 (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, 2018
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	Reclassifications Certain reclassifications have been made to the 2017 and 2016 Consolidated Financial Statements and Notes to the Consolidated Financial Statements to conform to the classifications used in 2018 .
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 Accounts payable and accrued 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 11. 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 $2 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 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 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.
Marketing and Administrative Expenses	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.
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 per share are computed using the weighted-average number of common shares outstanding during the period. Diluted earnings 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 Cash The Company defines cash and cash equivalents as cash and time deposits with maturities of three months or less when purchased.
Accounts Receivable	Accounts Receivable Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts is an estimate of the amount of probable credit losses in our existing accounts receivable. 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 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.
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 estimates in the discounted cash flow approach are cash flow forecasts of our reporting units, the discount rate, the terminal business value and the projected income tax rate. 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 projected income tax rates utilized are the statutory tax rates for the countries where each reporting unit operates. The terminal business value is determined by applying a business growth factor 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 projected cash flows, royalty rates, discount rate, projected income tax rate and terminal business 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. Identifiable intangible assets with a determinable useful life are amortized over that determinable life.
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. For the years ended December 31, 2018 , 2017 and 2016 , depreciation expense was $384 million , $340 million and $318 million , respectively. In 2018 , 2017 and 2016 , depreciation expense included $10 million , $17 million and $19 million , respectively, of accelerated depreciation related to restructuring actions further explained in Note 12 to the Consolidated Financial Statements. 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 would be material to the Company’s Consolidated Financial Statements in any given period.
Income Taxes	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 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 5 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 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. 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, and are substantially offset by net revaluation impacts on foreign currency denominated balance sheet exposures (which are also recorded in Other expenses, net).
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 5 and 13 for additional fair value disclosure of derivative financial instruments and long-term debt, respectively.
Foreign Currency	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 recored in Other expenses, net in the Consolidated Statements of Earnings 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 2014-09 "Revenue from Contracts with Customers (Topic 606)," as amended by ASU's 2015-14, 2016-08, 2016-10, 2016-11, 2016-12, 2016-20, 2017-05 and 2017-13 and 2017-14 This standard outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. Entities can adopt this standard either through a retrospective or modified-retrospective approach. January 1, 2018 The adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to Note 3 for transition disclosures, as well as other ongoing disclosure requirements. ASU 2016-16 "Income Taxes (Topic 740)" This standard requires that an entity recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. January 1, 2018 The adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to Note 20 of the Consolidated Financial Statements for a detailed explanation of the cumulative effect of adoption recognized on January 1, 2018. ASU 2017-07 "Compensation - Retirement Benefits (Topic 715)" This standard requires that the other components of net benefit cost be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. Retrospective application is required upon adoption of the presentation elements of this standard. January 1, 2018 The adoption of this standard did not have a material effect on our Consolidated Financial Statements for the year ended December 31, 2018. The standard's retrospective adoption, though, resulted in a full-year $60 million reclassification of non-service costs from various financial statement lines to non-operating expense, primarily related to pension settlement losses that were recorded in 2017. Please refer to Note 14 for additional detail on this adoption. ASU 2017-12 "Derivatives and Hedging (Topic 815)" This standard changes how an entity assesses effectiveness of derivative instruments, potentially resulting in less ineffectiveness and more derivatives qualifying for hedge accounting. Entities may early adopt the standard in any interim period, with the effect of adoption being applied to existing hedging relationships as of the beginning of the fiscal year of adoption. January 1, 2018 The early adoption of this standard did not have a material impact on our Consolidated Financial Statements. Please refer to Note 5 of the Consolidated Financial Statements for additional detail on this adoption. Recently issued standards: ASU 2016-02 "Leases (Topic 842)," as amended by ASU 2017-13, 2018-01, 2018-10, and 2018-11 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 The Company will adopt the accounting standard using the optional transition method, allowing us to record the cumulative effect adjustment of adopting the standard in the period of adoption, without restating prior periods presented. We are finalizing our assessment of our lease portfolio, implementation of systems, development of processes and internal controls and our accounting policy elections to comply with the standard's adoption requirements. We anticipate adoption of the standard will add approximately $200 to $250 million in right-of-use assets and lease obligations to our consolidated balance sheet and will not significantly impact results. (Our operating lease obligations are described in Note 9 of the Consolidated Financial Statements.) ASU 2016-13 "Financial Instruments - Credit Losses (Topic 326)" 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 are currently assessing the impact this standard will have on our Consolidated Financial Statements. Our current accounts receivable policy (as described in Note 1 of the Consolidated Financial Statements) uses historical and current information to estimate the amount of probable credit losses in our existing accounts receivable. We have not yet analyzed our current systems and methods to determine the impact of using forward-looking information to estimate expected credit losses. 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 do not believe the adoption of this guidance will 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, 2018
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, 2018 December 31, 2017 Land $ 224 $ 251 Buildings and leasehold improvements 1,091 944 Machinery and equipment 4,628 4,211 Construction in progress 443 350 6,386 5,756 Accumulated depreciation (2,575 ) (2,331 ) Property, plant and equipment, net $ 3,811 $ 3,425

SEGMENT INFORMATION (TABLE)

SEGMENT INFORMATION (TABLE)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated	The following table summarizes our net sales by segment and geographic region (in millions). Corporate eliminations (shown below) largely reflect the 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, 2018 2017 2016 Reportable Segments Composites $ 2,041 $ 2,068 $ 1,952 Insulation 2,720 2,001 1,748 Roofing 2,492 2,553 2,194 Total reportable segments 7,253 6,622 5,894 Corporate eliminations (196 ) (238 ) (217 ) NET SALES $ 7,057 $ 6,384 $ 5,677
Schedule of Revenues by Geographical Areas	External Customer Sales by Geographic Region United States $ 4,647 $ 4,495 $ 3,963 Europe 1,209 661 550 Asia Pacific 656 675 666 Canada and other 545 553 498 NET SALES $ 7,057 $ 6,384 $ 5,677
Schedule of Earnings before Interest and Taxes	The following table summarizes EBIT by segment (in millions): Twelve Months Ended December 31, 2018 2017 2016 Reportable Segments Composites $ 251 $ 291 $ 264 Insulation 290 177 126 Roofing 434 535 486 Total reportable segments 975 1,003 876 Restructuring costs (22 ) (48 ) (28 ) Acquisition-related costs (16 ) (15 ) (9 ) Recognition of acquisition inventory fair value step-up (2 ) (5 ) (10 ) Litigation settlement gain, net of legal fees — 29 — Pension settlement losses — (64 ) — Environmental liability charges — (15 ) — General corporate expense and other (114 ) (148 ) (130 ) Total Corporate, other and eliminations $ (154 ) $ (266 ) $ (177 ) EBIT $ 821 $ 737 $ 699
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 2018 2017 Reportable Segments Composites $ 2,480 $ 2,486 Insulation 4,907 3,618 Roofing 1,750 1,621 Total reportable segments 9,137 7,725 Cash and cash equivalents 78 246 Noncurrent deferred income taxes 43 144 Investments in affiliates 51 52 Assets held for sale 3 12 Corporate property, plant and equipment, other assets and eliminations 459 453 CONSOLIDATED TOTAL ASSETS $ 9,771 $ 8,632
Schedule of Property, Plant and Equipment by Geographical Areas	December 31, PROPERTY, PLANT AND EQUIPMENT BY GEOGRAPHIC REGION 2018 2017 United States $ 2,166 $ 2,164 Europe 779 479 Asia Pacific 567 459 Canada and other 299 323 TOTAL PROPERTY, PLANT AND EQUIPMENT $ 3,811 $ 3,425
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, 2018 2017 2016 Reportable Segments Composites $ 147 $ 144 $ 138 Insulation 186 124 106 Roofing 51 50 46 Total reportable segments 384 318 290 General corporate depreciation and amortization (a) 49 53 53 CONSOLIDATED PROVISION FOR DEPRECIATION AND AMORTIZATION $ 433 $ 371 $ 343 (a) In 2018 , 2017 and 2016, General corporate depreciation and amortization expense included $10 million , $17 million and $19 million , respectively, of accelerated depreciation related to restructuring actions further explained in Note 12 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, 2018 2017 2016 Reportable Segments Composites (a) $ 154 $ 148 $ 152 Insulation 240 151 154 Roofing 91 66 66 Total reportable segments 485 365 372 General corporate additions 57 37 42 CONSOLIDATED ADDITIONS TO PROPERTY, PLANT AND EQUIPMENT $ 542 $ 402 $ 414 (a) The 2018 figure for Composites includes $12 million of capital expenditures related to an acquired non-wovens plant, which was accounted for as an asset acquisition.

REVENUE (TABLE)

REVENUE (TABLE)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table shows a disaggregation of Net sales (in millions): For the 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 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

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (TABLE)	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Derivative assets designated as hedging instruments: Net investment hedges: Cross currency swaps Other current assets $ 9 $ 7 Cash flow hedges: Natural gas forward swaps Other current assets $ — $ 1 Derivative liabilities designated as hedging instruments: Net investment hedges: Cross-currency swaps Other liabilities $ 17 $ 38 Cash flow hedges: Natural gas forward swaps Accounts payable and accrued liabilities $ 1 $ 1 Derivative assets not designated as hedging instruments: Foreign exchange forward contracts Other current assets $ 1 $ 1 Derivative liabilities not designated as hedging instruments: Foreign exchange forward contracts Accounts payable and accrued liabilities $ 8 $ 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 (in millions): Twelve Months Ended Location 2018 2017 2016 Derivative activity designated as hedging instruments: Natural gas cash flow hedges: Amount of (gain)/loss reclassified from AOCI into earnings Cost of sales $ (2 ) $ (1 ) $ 6 Amount of loss recognized in earnings (ineffective portion) Other expenses, net $ — $ 2 $ — Cross-currency swap net investment hedges: Amount of gain recognized in earnings on derivative amounts excluded from effectiveness testing Interest expense, net $ (12 ) $ — $ — Derivative activity not designated as hedging instruments: Natural gas: Amount of gain recognized in earnings Other expenses, net $ — $ — $ (2 ) Foreign currency: Amount of (gain)/loss recognized in earnings (a) Other expenses, net $ (55 ) $ 5 $ 3 (a) (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. The following table presents the impact of derivative activities on the Consolidated Statements of Comprehensive Earnings (in millions): Amount of (Gain) Loss Recognized in Comprehensive Earnings Twelve Months Ended December 31, Hedging Type Derivative Financial Instrument 2018 2017 Net investment hedge Cross-currency swaps $ (18 ) $ 38 Cash flow hedge Natural gas forward swaps $ — $ 4

INVENTORIES (TABLE)

INVENTORIES (TABLE)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	Inventories consist of the following (in millions): December 31, 2018 2017 Finished goods $ 730 $ 562 Materials and supplies 342 279 Total inventories $ 1,072 $ 841

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLE ASSETS (TABLE)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	Intangible assets and goodwill consist of the following (in millions): December 31, 2018 Weighted Average Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable intangible assets: Customer relationships 20 years $ 554 $ (138 ) $ 416 Technology 17 years 321 (134 ) 187 Other 14 years 60 (28 ) 32 Indefinite-lived intangible assets: Trademarks 1,144 — 1,144 Total intangible assets $ 2,079 $ (300 ) $ 1,779 Goodwill $ 1,949 December 31, 2017 Weighted Average Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable intangible assets: Customer relationships 20 years $ 363 $ (109 ) $ 254 Technology 18 years 255 (116 ) 139 Other 8 years 47 (26 ) 21 Indefinite-lived intangible assets: Trademarks 946 — 946 Total intangible assets $ 1,611 $ (251 ) $ 1,360 Goodwill $ 1,507
Schedule of Finite-Lived Intangible Assets	The changes in the gross carrying amount of intangible assets by asset group are as follows (in millions): Customer Relationships Technology Trademarks Other Total Balance at December 31, 2017 $ 363 $ 255 $ 946 $ 47 $ 1,611 Acquisitions (see Note 8) 215 73 213 7 508 Other additions, net — — — 8 8 Foreign currency translation (24 ) (7 ) (15 ) (2 ) (48 ) Balance at December 31, 2018 $ 554 $ 321 $ 1,144 $ 60 $ 2,079
Schedule of Goodwill	he changes in the net carrying amount of goodwill by segment are as follows (in millions): Composites Insulation Roofing Total Balance at December 31, 2017 $ 58 1,049 $ 400 $ 1,507 Acquisitions (see Note 8) — 494 — 494 Foreign currency translation (1 ) (48 ) (3 ) (52 ) Balance at December 31, 2018 $ 57 $ 1,495 $ 397 $ 1,949
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 (a) 2019 $ 51 2020 $ 51 2021 $ 50 2022 $ 46 2023 $ 42 (a) The yearly amortization amounts in the table above include approximately $16 million of amortization expense related to the amortizable intangible assets acquired as part of the Paroc acquisition; see Note 8 for more details of this acquisition.

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (TABLE)	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Land $ 224 $ 251 Buildings and leasehold improvements 1,091 944 Machinery and equipment 4,628 4,211 Construction in progress 443 350 6,386 5,756 Accumulated depreciation (2,575 ) (2,331 ) Property, plant and equipment, net $ 3,811 $ 3,425

ACQUISITIONS (TABLE)

ACQUISITIONS (TABLE)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Finite-lived Intangible Assets Amortization Expense [Table Text Block]	The following table details the identifiable indefinite and definite-lived intangible assets acquired, their fair values (in millions) and estimated weighted average useful lives: Type of Intangible Asset Fair Value Weighted Average Useful Life Customer relationships $ 107 19 Technology 37 15 Trademarks 101 indefinite Total $ 245 The following table details the identifiable indefinite and definite-lived intangible assets acquired, their fair values (in millions) and estimated weighted average useful lives: Type of Intangible Asset Fair Value Weighted Average Useful Life Customer relationships $ 215 20 Technology - Know-how 61 15 Technology - Patented 12 5 Quarry Rights 7 45 Trademarks 213 Indefinite Total $ 508

OPERATING LEASES (TABLE)

OPERATING LEASES (TABLE)	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	At December 31, 2018 , the minimum future rental commitments under non-cancelable operating leases with initial maturities greater than one year, payable over the remaining lives of the leases are (in millions): Period Minimum Future Rental Commitments 2019 $ 83 2020 $ 64 2021 $ 47 2022 $ 31 2023 $ 18 2024 and beyond $ 27

TOTAL CURRENT LIABILITIES (TABL

TOTAL CURRENT LIABILITIES (TABLE)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	liabilities consist of the following current portions of these liabilities (in millions): December 31, 2018 2017 Accounts payable $ 851 $ 834 Payroll, vacation pay and incentive compensation 157 198 Payroll, property and other taxes 43 71 Other 227 179 Total $ 1,278 $ 1,282

WARRANTIES (TABLE)

WARRANTIES (TABLE)	12 Months Ended
	Dec. 31, 2018
Product Warranties Disclosures [Abstract]
Schedule of Product Warranty Liability	A reconciliation of the warranty liability is as follows (in millions): December 31, 2018 2017 Beginning balance $ 55 $ 52 Amounts accrued for current year 20 18 Settlements of warranty claims (15 ) (15 ) Ending balance $ 60 $ 55

RESTRUCTURING AND ACQUISITION_2

RESTRUCTURING AND ACQUISITION-RELATED COSTS (TABLE)	12 Months Ended
	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Schedule of Business Acquisitions by Acquisition, Contingent Consideration	The following table presents the impact and respective location of acquisition-related costs for 2018 in the Consolidated Statements of Earnings (in millions): Location Paroc Acquistion Pittsburgh Corning Acquisition Total Marketing and administrative expenses $ 5 $ 2 $ 7 Other expenses, net 9 — 9 Total acquisition-related costs $ 14 $ 2 $ 16
Restructuring and Related Costs	The following table presents the impact and respective location of total restructuring costs on the Consolidated Statements of Earnings, which are included in our Corporate, Other and Eliminations category (in millions): Twelve Months Ended December 31, Type of Cost Location 2018 2017 2016 Accelerated depreciation Cost of sales $ 10 $ 17 $ 19 Other exit costs Cost of sales 7 3 6 Severance Other expenses, net 4 27 1 Other exit costs Other expenses, net 1 1 2 Total restructuring costs $ 22 $ 48 $ 28
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): 2017 Cost Reduction Actions Pittsburgh Corning Acquisition-Related Restructuring Total Balance at December 31, 2017 $ 11 $ 9 $ 20 Restructuring costs 19 3 22 Payments (14 ) (4 ) (18 ) Non-cash items and reclassifications to other accounts (6 ) (1 ) (7 ) Balance at December 31, 2018 $ 10 $ 7 $ 17 Cumulative charges incurred $ 48 $ 20 $ 68

DEBT (TABLE)

DEBT (TABLE)	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value 4.20% senior notes, net of discount and financing fees, due 2022 $ 598 99 % $ 597 105 % 4.20% senior notes, net of discount and financing fees, due 2024 393 99 % 392 105 % 3.40% senior notes, net of discount and financing fees, due 2026 396 90 % 395 98 % 7.00% senior notes, net of discount and financing fees, due 2036 400 112 % 400 132 % 4.30% senior notes, net of discount and financing fees, due 2047 588 76 % 588 99 % 4.40% senior notes, net of discount and financing fees, due 2048 389 77 % — n/a Accounts receivable securitization facility, maturing in 2020 (a) 75 100 % — n/a Various capital leases, due through and beyond 2050 (a) 27 100 % 31 100 % Term loan borrowing, maturing in 2021 (a) 500 100 % — n/a Unamortized interest rate swap basis adjustment 5 n/a 6 n/a Total long-term debt 3,371 n/a 2,409 n/a Less – current portion (a) 9 100 % 4 100 % Long-term debt, net of current portion $ 3,362 n/a $ 2,405 n/a (a) The Company determined that the book value of the above noted 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.
Schedule of Line of Credit Facilities	The following table shows how the Company utilized its primary sources of liquidity (in millions): As of December 31, 2018 Senior Revolving Credit Facility Receivables Securitization Facility Facility size $ 800 $ 280 Collateral capacity limitation on availability n/a — Outstanding borrowings — 75 Outstanding letters of credit 9 3 Availability on facility $ 791 $ 202
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, 2018 and thereafter are presented in the table below (in millions). The maturities below are the aggregate par amounts of the outstanding senior notes and borrowings from the Term Loan, Receivables Securitization Facility, and capital lease liabilities: Period Maturities 2019 $ 11 2020 142 2021 441 2022 605 2023 4 2024 and beyond 2,217 Total $ 3,420

PENSION PLANS (TABLE)

PENSION PLANS (TABLE)	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Prospective Adoption of New Accounting Pronouncements	The following tables show the location and impact of the adoption on certain periods in the Consolidated Statements of Earnings: Twelve Months Ended December 31, 2017 Location Before Adoption Adoption Impact After Adoption Cost of sales $ 4,812 $ 3 $ 4,815 Other expenses, net $ 130 $ (63 ) $ 67 Non-operating (income) expense $ — $ 60 $ 60 Twelve Months Ended December 31, 2016 Location Before Adoption Adoption Impact After Adoption Cost of sales $ 4,296 $ 4 $ 4,300 Other expenses, net $ 16 $ (2 ) $ 14 Non-operating (income) expense $ — $ (2 ) $ (2 )
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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 993 $ 457 $ 1,450 $ 1,066 $ 512 $ 1,578 Service cost 6 6 12 7 5 12 Interest cost 34 13 47 40 15 55 Actuarial loss (gain) (67 ) (18 ) (85 ) 30 (16 ) 14 Currency loss (gain) — (26 ) (26 ) — 42 42 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — 11 11 — 21 21 Other — 7 7 — 12 12 Benefit obligation at end of period $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450
Schedule of Changes in Fair Value of Plan Assets	December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Plan Assets Fair value of assets at beginning of period $ 836 $ 364 $ 1,200 $ 822 $ 393 $ 1,215 Actual return on plan assets (59 ) (8 ) (67 ) 114 26 140 Currency gain (loss) — (20 ) (20 ) — 31 31 Company contributions 25 15 40 50 22 72 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — — — — 14 14 Other — — — — 12 12 Fair value of assets at end of period $ 727 $ 328 $ 1,055 $ 836 $ 364 $ 1,200 Funded status $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 )
Schedule of Amounts Recognized in Balance Sheet	December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 7 $ 7 $ — $ 7 $ 7 Accrued pension cost – current — (2 ) (2 ) — (1 ) (1 ) Accrued pension cost – non-current (164 ) (104 ) (268 ) (157 ) (99 ) (256 ) Net amount recognized $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Amounts Recorded in AOCI Net actuarial loss $ (392 ) $ (92 ) $ (484 ) $ (357 ) $ (86 ) $ (443 )
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, 2018 2017 United States Plans Discount rate 4.25 % 3.55 % Expected return on plan assets 6.75 % 6.75 % Non-United States Plans Discount rate 3.04 % 2.88 % Expected return on plan assets 4.91 % 5.22 % Rate of compensation increase 4.14 % 4.29 %
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, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 50 $ — $ — $ 50 International 52 — — 52 Fixed income and cash equivalents Corporate bonds — 236 — 236 Government debt — 91 — 91 Real estate investment trusts 24 — — 24 Total United States plan assets subject to leveling $ 126 $ 327 $ — 453 Plan assets measured at NAV Equities 123 Real assets 54 Fixed income and cash equivalents 53 Absolute return strategies 44 Total United States plan assets $ 727 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 67 $ — $ — $ 67 International 78 — — 78 Fixed income and cash equivalents Corporate bonds — 231 — 231 Government debt — 88 — 88 Real estate investment trusts 26 — — 26 Total United States plan assets subject to leveling $ 171 $ 319 $ — 490 Plan assets measured at NAV Equities 173 Real assets 51 Fixed income and cash equivalents 69 Absolute return strategies 53 Total United States plan assets $ 836 The following table summarizes the fair values and applicable fair value hierarchy levels of non-United States pension plan assets (in millions): December 31, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents Cash and cash equivalents — 62 — 62 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 78 $ — 78 Plan assets measured at NAV Equities 41 Fixed income and cash equivalents 109 Absolute return strategies 100 Total non-United States plan assets $ 328 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 3 $ — $ 3 Fixed income and cash equivalents Cash and cash equivalents — 64 — 64 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 79 $ — 79 Plan assets measured at NAV Equities 52 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 364
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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Plans with ABO in excess of fair value of plan assets: Projected benefit obligation $ 891 $ 269 $ 1,160 $ 993 $ 288 $ 1,281 Accumulated benefit obligation $ 891 $ 265 $ 1,156 $ 993 $ 284 $ 1,277 Fair value of plan assets $ 727 $ 169 $ 896 $ 836 $ 193 $ 1,029 Plans with fair value of assets in excess of ABO: Projected benefit obligation $ — $ 158 $ 158 $ — $ 169 $ 169 Accumulated benefit obligation $ — $ 140 $ 140 $ — $ 145 $ 145 Fair value of plan assets $ — $ 159 $ 159 $ — $ 171 $ 171 Summary of all plans: Total projected benefit obligation $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450 Total accumulated benefit obligation $ 891 $ 405 $ 1,296 $ 993 $ 429 $ 1,422 Total fair value of plan assets $ 727 $ 328 $ 1,055 $ 836 $ 364 $ 1,200
Schedule of Net Benefit Costs	The following table presents the components of net periodic pension cost (in millions): Twelve Months Ended December 31, 2018 2017 2016 Service cost $ 12 $ 12 $ 10 Interest cost 47 55 62 Expected return on plan assets (73 ) (79 ) (81 ) Amortization of actuarial loss 15 18 16 Settlement/curtailment — 64 (6 ) Other — — 2 Net periodic benefit cost $ 1 $ 70 $ 3
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, 2018 2017 2016 United States Plans Discount rate 3.55 % 3.95 % 4.20 % Expected return on plan assets 6.75 % 6.75 % 7.00 % Rate of compensation increase N/A (a) N/A (a) N/A (a) Non-United States Plans Discount rate 2.88 % 3.14 % 3.88 % Expected return on plan assets 5.22 % 5.92 % 6.23 % Rate of compensation increase 4.29 % 4.25 % 3.97 % (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 2019 $ 87 2020 $ 85 2021 $ 83 2022 $ 85 2023 $ 83 2024-2028 $ 398
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Allocation of Plan Assets	December 31, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities Domestic $ 50 $ — $ — $ 50 International 52 — — 52 Fixed income and cash equivalents Corporate bonds — 236 — 236 Government debt — 91 — 91 Real estate investment trusts 24 — — 24 Total United States plan assets subject to leveling $ 126 $ 327 $ — 453 Plan assets measured at NAV Equities 123 Real assets 54 Fixed income and cash equivalents 53 Absolute return strategies 44 Total United States plan assets $ 727
Foreign Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Allocation of Plan Assets	December 31, 2018 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 4 $ — $ 4 Fixed income and cash equivalents Cash and cash equivalents — 62 — 62 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 78 $ — 78 Plan assets measured at NAV Equities 41 Fixed income and cash equivalents 109 Absolute return strategies 100 Total non-United States plan assets $ 328 December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total Equities $ — $ 3 $ — $ 3 Fixed income and cash equivalents Cash and cash equivalents — 64 — 64 Corporate bonds — 12 — 12 Total non-United States plan assets subject to leveling $ — $ 79 $ — 79 Plan assets measured at NAV Equities 52 Fixed income and cash equivalents 123 Absolute return strategies 110 Total non-United States plan assets $ 364

POSTEMPLOYMENT AND POSTRETIRE_2

POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS (TABLE)	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 993 $ 457 $ 1,450 $ 1,066 $ 512 $ 1,578 Service cost 6 6 12 7 5 12 Interest cost 34 13 47 40 15 55 Actuarial loss (gain) (67 ) (18 ) (85 ) 30 (16 ) 14 Currency loss (gain) — (26 ) (26 ) — 42 42 Benefits paid (75 ) (17 ) (92 ) (53 ) (18 ) (71 ) Settlements/curtailments — (6 ) (6 ) (97 ) (116 ) (213 ) Acquisition — 11 11 — 21 21 Other — 7 7 — 12 12 Benefit obligation at end of period $ 891 $ 427 $ 1,318 $ 993 $ 457 $ 1,450
Schedule of Amounts Recognized in Balance Sheet	December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Amounts Recognized in the Consolidated Balance Sheets Prepaid pension cost $ — $ 7 $ 7 $ — $ 7 $ 7 Accrued pension cost – current — (2 ) (2 ) — (1 ) (1 ) Accrued pension cost – non-current (164 ) (104 ) (268 ) (157 ) (99 ) (256 ) Net amount recognized $ (164 ) $ (99 ) $ (263 ) $ (157 ) $ (93 ) $ (250 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Amounts Recorded in AOCI Net actuarial loss $ (392 ) $ (92 ) $ (484 ) $ (357 ) $ (86 ) $ (443 )
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, 2018 2017 United States Plans Discount rate 4.25 % 3.55 % Expected return on plan assets 6.75 % 6.75 % Non-United States Plans Discount rate 3.04 % 2.88 % Expected return on plan assets 4.91 % 5.22 % Rate of compensation increase 4.14 % 4.29 %
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, 2018 and 2017 (in millions): December 31, 2018 December 31, 2017 U.S. Non-U.S. Total U.S. Non-U.S. Total Change in Projected Benefit Obligation Benefit obligation at beginning of period $ 216 $ 14 $ 230 $ 212 $ 13 $ 225 Service cost 1 — 1 2 — 2 Interest cost 8 — 8 8 1 9 Actuarial gain (25 ) — (25 ) (13 ) (2 ) (15 ) Currency loss — (1 ) (1 ) — 1 1 Plan amendments (2 ) — (2 ) (3 ) — (3 ) Benefits paid (15 ) (1 ) (16 ) (12 ) (1 ) (13 ) Acquisition — — — 22 — 22 Other — — — — 2 2 Benefit obligation at end of period $ 183 $ 12 $ 195 $ 216 $ 14 $ 230 Funded status $ (183 ) $ (12 ) $ (195 ) $ (216 ) $ (14 ) $ (230 )
Schedule of Amounts Recognized in Balance Sheet	Amounts Recognized in the Consolidated Balance Sheets Accrued benefit obligation – current $ (17 ) $ — $ (17 ) $ (18 ) $ (1 ) $ (19 ) Accrued benefit obligation – non-current (166 ) (12 ) (178 ) (198 ) (13 ) $ (211 ) Net amount recognized $ (183 ) $ (12 ) $ (195 ) $ (216 ) $ (14 ) $ (230 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Amounts Recorded in AOCI Net actuarial loss (gain) $ (49 ) $ (5 ) $ (54 ) $ (29 ) $ (6 ) $ (35 ) Net prior service cost (credit) (9 ) — (9 ) (12 ) 1 (11 ) Net amount recognized $ (58 ) $ (5 ) $ (63 ) $ (41 ) $ (5 ) $ (46 )
Schedule of Assumptions Used to Determine Benefit Obligations	The following table presents the discount rates used to determine the benefit obligations: December 31, 2018 2017 United States plans 4.15 % 3.45 % Non-United States plans 4.59 % 4.56 %
Schedule of Net Benefit Costs	The following table presents the components of net periodic postretirement benefit cost (in millions): Twelve Months Ended December 31, 2018 2017 2016 Service cost $ 1 $ 2 $ 2 Interest cost 8 9 9 Amortization of prior service cost (4 ) (4 ) (4 ) Amortization of actuarial gain (6 ) (3 ) (1 ) Other — — 1 Net periodic postretirement benefit cost $ (1 ) $ 4 $ 7
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, 2018 2017 2016 United States plans 3.45 % 3.80 % 4.00 % Non-United States plans 4.56 % 6.78 % 3.80 %
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, 2018 2017 2016 United States plans Initial rate at end of year 6.75 % 6.56 % 6.78 % Ultimate rate 5.00 % 5.00 % 5.00 % Year in which ultimate rate is reached 2026 2025 2025 Non-United States plans Initial rate at end of year 5.40 % 5.73 % 5.07 % Ultimate rate 5.40 % 5.49 % 4.70 % Year in which ultimate rate is reached 2019 2019 2019
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]	To illustrate, a one-percentage point change in the December 31, 2018 assumed health care cost trend rate would have the following effects (in millions): 1-Percentage Point Increase Decrease Increase (decrease) in total service cost and interest cost components of net periodic postretirement benefit cost $ — $ — Increase (decrease) of accumulated postretirement benefit obligation $ 4 $ (3 )
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 2019 $ 18 2020 $ 18 2021 $ 17 2022 $ 17 2023 $ 16 2024-2028 $ 70

STOCK COMPENSATION (TABLE)

STOCK COMPENSATION (TABLE)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	The following table summarizes the Company’s stock option activity: Twelve Months Ended December 31, 2018 2017 2016 Number of Options Weighted- Average Exercise Price Number of Options Weighted- Average Exercise Price Number of Options Weighted- Average Exercise Price Beginning Balance 518,725 $ 37.17 975,400 $ 35.14 1,953,320 $ 31.09 Granted — — — — — — Exercised (39,100 ) 37.05 (453,425 ) 32.79 (960,570 ) 26.90 Forfeited (750 ) 37.65 (3,250 ) 37.65 (11,350 ) 38.50 Expired — — — — (6,000 ) 30.00 Ending Balance 478,875 $ 37.18 518,725 $ 37.17 975,400 $ 35.14
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable	The following table summarizes information about the Company’s options outstanding and exercisable: Options Outstanding Options Exercisable Weighted-Average Number Exercisable at Dec. 31, 2018 Weighted-Average Range of Exercise Prices Options Outstanding Remaining Contractual Life Exercise Price Remaining Contractual Life Exercise Price $13.89 - $42.16 478,875 4.00 $ 37.18 478,875 4.00 $ 37.18
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The following table shows a summary of the Company’s Restricted Stock plans: Twelve Months Ended December 31, 2018 2017 2016 Number of Shares Weighted- Average Grant Date Fair Value Number of Shares Weighted- Average Grant Date Fair Value Number of Shares Weighted- Average Grant Date Fair Value Beginning Balance 1,752,136 $ 42.40 1,800,557 $ 37.78 1,707,490 $ 35.37 Granted 365,363 84.34 496,021 56.60 544,627 45.61 Vested (558,288 ) 41.34 (477,857 ) 38.94 (398,751 ) 37.55 Forfeited (79,837 ) 54.20 (66,585 ) 44.90 (52,809 ) 39.80 Ending Balance 1,479,374 $ 52.30 1,752,136 $ 42.40 1,800,557 $ 37.78
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: Twelve Months Ended December 31, 2018 2017 2016 Number of PSUs Weighted- Average Grant Date Fair Value Number of PSUs Weighted- Average Grant Date Fair Value Number of PSUs Weighted- Average Grant Date Fair Value Beginning Balance 451,148 $ 53.96 472,300 $ 47.19 431,400 $ 44.52 Granted 171,725 94.14 221,050 59.71 244,250 48.74 Vested (212,852 ) 48.73 (219,050 ) 43.83 (186,750 ) 44.43 Forfeited/canceled (49,044 ) 60.31 (23,152 ) 49.50 (16,600 ) 44.48 Ending Balance 360,977 $ 75.23 451,148 $ 53.96 472,300 $ 47.19

CHANGES IN ACCUMULATED OTHER _2

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE DEFICIT (TABLE)	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 Currency Translation Adjustment Beginning balance $ (183 ) $ (284 ) Net investment hedge amounts classified into AOCI, net of tax 14 (24 ) (Loss) Gain on foreign currency translation (137 ) 125 Other comprehensive (loss)/income, net of tax (123 ) 101 Ending balance $ (306 ) $ (183 ) Pension and Other Postretirement Adjustment Beginning balance $ (331 ) $ (429 ) Amounts reclassified from AOCI to net earnings, net of tax (a) 4 53 Amounts classified into AOCI, net of tax (23 ) 45 Other comprehensive (loss)/income, net of tax (19 ) 98 Ending balance $ (350 ) $ (331 ) Hedging Adjustment Beginning balance $ — $ 3 Amounts reclassified from AOCI to net earnings, net of tax (b) (1 ) (1 ) Amounts classified into AOCI, net of tax 1 (2 ) Other comprehensive (loss), net of tax — (3 ) Ending balance $ — $ — Total AOCI ending balance $ (656 ) $ (514 ) (a) These AOCI components are included in the computation of total Pension and OPEB expense and are recorded in Cost of sales, marketing and administrative expenses and Other expenses, net. See Notes 14 and 15 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. See Note 5 for additional information.

EARNINGS PER SHARE (TABLE)

EARNINGS PER SHARE (TABLE)	12 Months Ended
	Dec. 31, 2018
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 per-share (in millions, except per share amounts): Twelve Months Ended December 31, 2018 2017 2016 Net earnings attributable to Owens Corning $ 545 $ 289 $ 393 Weighted-average number of shares outstanding used for basic earnings per share 110.4 111.5 114.4 Non-vested restricted and performance shares 0.8 1.5 0.8 Options to purchase common stock 0.2 0.2 0.2 Weighted-average number of shares outstanding and common equivalent shares used for diluted earnings per share 111.4 113.2 115.4 Earnings per common share attributable to Owens Corning common stockholders: Basic $ 4.94 $ 2.59 $ 3.44 Diluted $ 4.89 $ 2.55 $ 3.41

INCOME TAXES (TABLE)

INCOME TAXES (TABLE)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The following table summarizes our Earnings before taxes and Income tax expense (in millions): Twelve Months Ended December 31, 2018 2017 2016 Earnings before taxes: United States $ 411 $ 342 $ 281 Foreign 293 217 309 Total $ 704 $ 559 $ 590
Schedule of Components of Income Tax Expense (Benefit), By Jurisdiction	Income tax expense: Current United States $ (10 ) $ (2 ) $ (7 ) State and local 6 5 4 Foreign 19 83 55 Total current 15 86 52 Deferred United States 114 196 117 State and local 12 3 8 Foreign 15 (16 ) 11 Total deferred 141 183 136 Total income tax expense $ 156 $ 269 $ 188
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, 2018 2017 2016 United States federal statutory rate 21 % 35 % 35 % State and local income taxes, net of federal tax benefit 2 2 2 Foreign tax rate differential — (5 ) (4 ) U.S. tax expense on foreign earnings 2 49 2 Legislative tax rate changes — (9 ) 1 Foreign tax credits — (29 ) — Valuation allowance 2 3 (3 ) Uncertain tax positions and settlements (5 ) 1 1 Excess tax benefits related to stock compensation (2 ) (1 ) (1 ) Other, net 2 2 (1 ) Effective tax rate 22 % 48 % 32 %
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, 2018 December 31, 2017 Deferred Tax Assets Deferred Tax Liabilities Deferred Tax Assets Deferred Tax Liabilities Other employee benefits $ 87 $ — $ 92 $ — Pension plans 66 — 48 — Operating loss and tax credit carryforwards 255 — 377 — Depreciation — 259 — 234 Amortization — 395 — 314 Foreign tax credits 161 — 160 — State and local taxes 3 — 3 — Other 61 — 69 — Subtotal 633 654 749 548 Valuation allowances (78 ) — (94 ) — Total deferred taxes $ 555 $ 654 $ 655 $ 548
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, 2018 (in millions): Expiration Dates Amounts U.S. federal loss carryforwards 2027 – 2032 $ 65 U.S. state loss carryforwards (a) 2019 – 2034 58 Foreign loss and tax credit carryforwards Indefinite 37 Foreign loss and tax credit carryforwards (a) 2019 – 2034 65 Other U.S. federal and state tax credits 2028 – 2034 30 Total operating loss and tax credit carryforwards $ 255 U.S foreign tax credits 2027 $ 161 (a) As of December 31, 2018 , $8 million of U.S. state and $6 million of foreign deferred tax assets related to loss carryforwards 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, 2018 2017 2016 Balance at beginning of period $ 90 $ 98 $ 84 Tax positions related to the current year Gross additions 6 1 1 Tax positions related to prior years Gross additions 36 13 19 Gross reductions (37 ) (11 ) (5 ) Settlements (5 ) (12 ) (1 ) Expiration of statute of limitations (4 ) — — Impact of currency changes (2 ) 1 — Balance at end of period $ 84 $ 90 $ 98

QUARTERLY FINANCIAL INFORMATI_2

QUARTERLY FINANCIAL INFORMATION (unaudited) (TABLE)	12 Months Ended
	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information	Quarter First Second Third Fourth 2017 Net sales $ 1,478 $ 1,597 $ 1,703 $ 1,606 Gross margin (a) $ 342 $ 408 $ 423 $ 396 Income tax expense (b) $ 43 $ 67 $ 32 $ 127 Net earnings (loss) attributable to Owens Corning $ 101 $ 96 $ 96 $ (4 ) BASIC EARNINGS (LOSS) PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.90 $ 0.86 $ 0.86 $ (0.04 ) DILUTED EARNINGS (LOSS) PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.89 $ 0.85 $ 0.85 $ (0.04 ) Select quarterly financial information is presented in the tables below for the quarterly periods (in millions, except per share amounts): Quarter First Second Third Fourth 2018 Net sales $ 1,691 $ 1,824 $ 1,818 $ 1,724 Gross margin $ 355 $ 418 $ 448 $ 411 Income tax expense $ 11 $ 49 $ 67 $ 29 Net earnings attributable to Owens Corning $ 92 $ 121 $ 161 $ 171 BASIC EARNINGS PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.83 $ 1.09 $ 1.46 $ 1.56 DILUTED EARNINGS PER COMMON SHARE ATTRIBUTABLE TO OWENS CORNING COMMON STOCKHOLDERS $ 0.82 $ 1.08 $ 1.45 $ 1.55

BUSINESS AND SUMMARY OF SIGNI_4

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (DETAIL) $ / shares in Units, $ in Millions	Feb. 01, 2019$ / shares	Dec. 31, 2018USD ($)segment$ / shares	Dec. 31, 2017USD ($)$ / shares	Dec. 31, 2016USD ($)$ / shares
Property Plant And Equipment [Line Items]
Number of reportable segments | segment		3
Dividend (dollars per share) | $ / shares		$ 0.85	$ 0.81	$ 0.74
Revenue, remaining performance obligation		$ 2
Marketing and advertising expense		120	$ 108	$ 105
Amortization of intangible assets		$ 49	31	25
Precious metals depletion, percentage		3.00%
Depreciation		$ 384	340	318
Foreign currency transaction gain (loss)		7	4	2
Other Current Assets
Property Plant And Equipment [Line Items]
Restricted cash and cash equivalents		7	7	6
Other Noncurrent Assets
Property Plant And Equipment [Line Items]
Investments in affiliates		51	52
Subsequent Event
Property Plant And Equipment [Line Items]
Dividend (dollars per share) | $ / shares	$ 0.22
Other Restructuring
Property Plant And Equipment [Line Items]
Accelerated depreciation related to cost reduction actions		$ 10	$ 17	$ 19
Minimum
Property Plant And Equipment [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period		16 years
Minimum | Accounting Standards Update 2017-07
Property Plant And Equipment [Line Items]
Service cost		$ 60
Minimum | Accounting Standards Update 2016-02
Property Plant And Equipment [Line Items]
Finance lease, right-of-use asset		$ 250
Maximum
Property Plant And Equipment [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period		20 years
Maximum | Accounting Standards Update 2016-02
Property Plant And Equipment [Line Items]
Finance lease, right-of-use asset		$ 300

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, 2018
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) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3
Other Restructuring
Segment Reporting Information [Line Items]
Accelerated depreciation related to cost reduction actions | $	$ 10	$ 17	$ 19

SEGMENT INFORMATION - Net Sales

SEGMENT INFORMATION - Net Sales by Reportable Segments and Geographic Region (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 7,057	$ 6,384	$ 5,677
Composites
Segment Reporting Information [Line Items]
Revenues	2,041	2,068	1,952
Insulation
Segment Reporting Information [Line Items]
Revenues	2,720	2,001	1,748
Roofing
Segment Reporting Information [Line Items]
Revenues	2,492	2,553	2,194
Total Segments
Segment Reporting Information [Line Items]
Revenues	7,253	6,622	5,894
Corporate Eliminations
Segment Reporting Information [Line Items]
Revenues	(196)	(238)	(217)
United States
Segment Reporting Information [Line Items]
Revenues	4,647	4,495	3,963
Europe
Segment Reporting Information [Line Items]
Revenues	1,209	661	550
Asia Pacific
Segment Reporting Information [Line Items]
Revenues	656	675	666
Other Geographical
Segment Reporting Information [Line Items]
Revenues	$ 545	$ 553	$ 498

SEGMENT INFORMATION - EBIT by S

SEGMENT INFORMATION - EBIT by Segment (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Restructuring costs	$ (22)	$ (48)	$ (28)
Acquisition-related costs	(16)	(15)	(9)
Recognition of InterWrap inventory fair value step-up	(2)	(5)	(10)
Litigation settlement gain, net of legal fees	(36)	(67)	(14)
Environmental liability charges	0	(15)	0
General corporate expense and other	(114)	(148)	(130)
Total Corporate, other and eliminations	821	737	699
Composites
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations	251	291	264
Insulation
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations	290	177	126
Roofing
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations	434	535	486
Total Segments
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations	975	1,003	876
Corporate Eliminations
Segment Reporting Information [Line Items]
Total Corporate, other and eliminations	(154)	(266)	(177)
Other Expense
Segment Reporting Information [Line Items]
Acquisition-related costs	(9)
Litigation settlement gain, net of legal fees	0	(29)	0
Pension Plan
Segment Reporting Information [Line Items]
Pension settlement losses	0	(64)	6
Foreign Plan | Pension Plan
Segment Reporting Information [Line Items]
Pension settlement losses	$ 0	$ (64)	$ 0

SEGMENT INFORMATION - Total Ass

SEGMENT INFORMATION - Total Assets and Property, Plant and Equipment by Geographic Region (DETAIL) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total Assets	$ 9,771	$ 8,632
Cash and cash equivalents	78	246
Noncurrent deferred income taxes	43	144
Investments in affiliates	51	52
Assets held for sale	3	12
Corporate property, plant and equipment, net	459	453
Property, plant and equipment, net	3,811	3,425
Composites
Segment Reporting Information [Line Items]
Total Assets	2,480	2,486
Insulation
Segment Reporting Information [Line Items]
Total Assets	4,907	3,618
Roofing
Segment Reporting Information [Line Items]
Total Assets	1,750	1,621
Total Segments
Segment Reporting Information [Line Items]
Total Assets	9,137	7,725
United States
Segment Reporting Information [Line Items]
Property, plant and equipment, net	2,166	2,164
Europe
Segment Reporting Information [Line Items]
Property, plant and equipment, net	779	479
Asia Pacific
Segment Reporting Information [Line Items]
Property, plant and equipment, net	567	459
Other Geographical
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 299	$ 323

SEGMENT INFORMATION - Provision

SEGMENT INFORMATION - Provision For Depreciation and Amortization (DETAIL) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Depreciation and amortization		$ 433	$ 371	$ 343
Composites
Segment Reporting Information [Line Items]
Depreciation and amortization		147	144	138
Insulation
Segment Reporting Information [Line Items]
Depreciation and amortization		186	124	106
Roofing
Segment Reporting Information [Line Items]
Depreciation and amortization		51	50	46
Total Segments
Segment Reporting Information [Line Items]
Depreciation and amortization		384	318	290
General Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization	[1]	$ 49	$ 53	$ 53
[1]	In 2018, 2017 and 2016, General corporate depreciation and amortization expense included $10 million, $17 million and $19 million, respectively, of accelerated depreciation related to restructuring actions further explained in Note 12 to the Consolidated Financial Statements.ADDITIONS TO PROPERTY, PLANT AND

SEGMENT INFORMATION - Additions

SEGMENT INFORMATION - Additions to Property, Plant and Equipment (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	$ 542	$ 402	$ 414
Composites
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	154	148	152
Insulation
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	240	151	154
Roofing
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	91	66	66
Total Segments
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	485	365	372
General Corporate
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	$ 57	$ 37	$ 42

REVENUE - Narrative (DETAIL)

REVENUE - Narrative (DETAIL) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Accumulated earnings		$ 2,013		$ 1,575
Inventories		1,072		$ 841
Contract with customer, liability	$ 53		$ 46
Contract with customer, liability, revenue recognized	$ 14
Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Accumulated earnings			$ 2
Calculated under Revenue Guidance in Effect before Topic 606
Disaggregation of Revenue [Line Items]
Inventories		$ 2

REVENUE - Disaggregated Revenue

REVENUE - Disaggregated Revenue (DETAIL) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Net sales	$ 1,724	$ 1,818	$ 1,824	$ 1,691	$ 1,606	$ 1,703	$ 1,597	$ 1,478	$ 7,057	$ 6,384	$ 5,677
Europe
Disaggregation of Revenue [Line Items]
Net sales									1,209
Asia-Pacific
Disaggregation of Revenue [Line Items]
Net sales									656
Rest of world
Disaggregation of Revenue [Line Items]
Net sales									545
Composites
Disaggregation of Revenue [Line Items]
Net sales									2,041
Composites | Europe
Disaggregation of Revenue [Line Items]
Net sales									590
Composites | Asia-Pacific
Disaggregation of Revenue [Line Items]
Net sales									464
Composites | Rest of world
Disaggregation of Revenue [Line Items]
Net sales									126
Insulation
Disaggregation of Revenue [Line Items]
Net sales									2,720
Insulation | Europe
Disaggregation of Revenue [Line Items]
Net sales									605
Insulation | Asia-Pacific
Disaggregation of Revenue [Line Items]
Net sales									178
Insulation | Rest of world
Disaggregation of Revenue [Line Items]
Net sales									322
Roofing
Disaggregation of Revenue [Line Items]
Net sales									2,492
Roofing | Europe
Disaggregation of Revenue [Line Items]
Net sales									14
Roofing | Asia-Pacific
Disaggregation of Revenue [Line Items]
Net sales									15
Roofing | Rest of world
Disaggregation of Revenue [Line Items]
Net sales									103
Eliminations
Disaggregation of Revenue [Line Items]
Net sales									(196)
Eliminations | Europe
Disaggregation of Revenue [Line Items]
Net sales									0
Eliminations | Asia-Pacific
Disaggregation of Revenue [Line Items]
Net sales									(1)
Eliminations | Rest of world
Disaggregation of Revenue [Line Items]
Net sales									(6)
Residential | United States
Disaggregation of Revenue [Line Items]
Net sales									3,275
Residential | Composites | United States
Disaggregation of Revenue [Line Items]
Net sales									263
Residential | Insulation | United States
Disaggregation of Revenue [Line Items]
Net sales									990
Residential | Roofing | United States
Disaggregation of Revenue [Line Items]
Net sales									2,199
Residential | Eliminations | United States
Disaggregation of Revenue [Line Items]
Net sales									(177)
Commercial and Industrial Sector | United States
Disaggregation of Revenue [Line Items]
Net sales									1,372
Commercial and Industrial Sector | Composites | United States
Disaggregation of Revenue [Line Items]
Net sales									598
Commercial and Industrial Sector | Insulation | United States
Disaggregation of Revenue [Line Items]
Net sales									625
Commercial and Industrial Sector | Roofing | United States
Disaggregation of Revenue [Line Items]
Net sales									161
Commercial and Industrial Sector | Eliminations | United States
Disaggregation of Revenue [Line Items]
Net sales									$ (12)

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (BALANCE SHEET) (DETAIL) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
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	$ 9	$ 7
Other Current Assets | Designated as Hedging Instrument | Cash Flow Hedging | Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net	0	1
Other Current Assets | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net	1	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	17	38
Accounts Payable and Accrued Liabilities | Designated as Hedging Instrument | Cash Flow Hedging | Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Net	1	1
Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Net	$ 8	$ 1

INVENTORIES (DETAIL)

INVENTORIES (DETAIL) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Finished goods	$ 730	$ 562
Materials and supplies	342	279
Total inventories	$ 1,072	$ 841

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS (NOTIONAL AMOUNTS) (DETAIL) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Foreign Exchange Forward | United States
Derivative [Line Items]
Notional amount (in US$)	$ 731	$ 109

DERIVATIVE FINANCIAL INSTRUME_5

DERIVATIVE FINANCIAL INSTRUMENTS (INCOME STMT) (DETAIL) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cost of Sales | Designated as Hedging Instrument | Energy Related Derivative
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ 2	$ 1	$ (6)
Other Expense | Designated as Hedging Instrument | Energy Related Derivative
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Loss Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing		0	(2)	0
Other Expense | Not Designated as Hedging Instrument | Energy Related Derivative
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Loss Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing		0	0	2
Other Expense | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Loss Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing		55	(5)	(3)
Interest Expense | Designated as Hedging Instrument | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Derivative, Gain on Derivative		(12)	$ 0	$ 0
Net Investment Hedging | Cross Currency Interest Rate Contract
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Loss Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing	$ 18	(38)
Cash Flow Hedging | Energy Related Derivative
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Loss Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing	$ 0	$ (4)

DERIVATIVE FINANCIAL INSTRUME_6

DERIVATIVE FINANCIAL INSTRUMENTS NARRATIVE (DETAIL) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)MMBTU	Dec. 31, 2017USD ($)MMBTU
Derivative [Line Items]
Notional amount, energy measure | MMBTU	2	5
Net fair value liability	$ 14
Natural Gas Contract
Derivative [Line Items]
Derivative, remaining maturity	15 months
Twelve Months
Derivative [Line Items]
Percent of exposures hedged	0.75
Beyond Twelve Months
Derivative [Line Items]
Percent of exposures hedged	0.65
Three Months
Derivative [Line Items]
Percent of exposures hedged	0.75
Exposure time	3 months
Three Months
Derivative [Line Items]
Percent of exposures hedged	0.60
Exposure time	3 months
Dollars | Cross Currency Interest Rate Contract
Derivative [Line Items]
Notional amount (in US$)	$ 516
Euros | Foreign Exchange Forward
Derivative [Line Items]
Notional amount (in US$)	121
United States | Foreign Exchange Forward
Derivative [Line Items]
Notional amount (in US$)	$ 731	$ 109

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLE ASSETS (DETAIL) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets [Line Items]
Gross Carrying Amount		$ 2,079	$ 1,611
Accumulated Amortization		(300)	(251)
Net Carrying Amount		1,779	1,360
Goodwill		1,949	1,507
2,019	[1],[2]	51
2,020	[1],[2]	51
2,021	[1],[2]	50
2,022	[1],[2]	46
2,023	[1],[2]	42
Acquisitions		494
Amortization of intangible assets		$ 49	$ 31	$ 25
Other
Intangible Assets [Line Items]
Weighted Average Useful Life		45 years
Customer Relationships
Intangible Assets [Line Items]
Weighted Average Useful Life		20 years	20 years
Gross Carrying Amount		$ 554	$ 363
Accumulated Amortization		(138)	(109)
Net Carrying Amount		$ 416	$ 254
Technology
Intangible Assets [Line Items]
Weighted Average Useful Life		17 years	18 years
Gross Carrying Amount		$ 321	$ 255
Accumulated Amortization		(134)	(116)
Net Carrying Amount		$ 187	$ 139
Franchise Rights and Other Agreements
Intangible Assets [Line Items]
Weighted Average Useful Life		14 years	8 years
Gross Carrying Amount		$ 60	$ 47
Accumulated Amortization		(28)	(26)
Net Carrying Amount		32	21
Trademarks
Intangible Assets [Line Items]
Gross Carrying Amount		1,144	946
Accumulated Amortization		0	0
Net Carrying Amount		1,144	$ 946
Pittsburgh Corning Corporation
Intangible Assets [Line Items]
Amortization of intangible assets		$ 16
[1]	The yearly amortization amounts in the table above include approximately $16 million of amortization expense related to the amortizable intangible assets acquired as part of the Paroc acquisition; see Note 8 for more details of this acquisition.
[2]	a) The yearly amortization amounts in the table above include approximately $16 million of amortization expense related to the amortizable intangible assets acquired as part of the Paroc acquisition; see Note 8 for more details of this acquisition.

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLE ASSETS (ROLLFORWARD) (DETAIL)	12 Months Ended
	Dec. 31, 2018USD ($)
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	$ 1,611,000,000
Acquisitions	508,000,000
Other additions, net	8,000,000
Foreign currency translation	48,000,000
Ending Balance	2,079,000,000
Goodwill [Roll Forward]
Beginning Balance	1,507,000,000
Acquisitions	494,000,000
Foreign currency translation	(52,000,000)
Ending Balance	1,949,000,000
Composites
Goodwill [Roll Forward]
Beginning Balance	58,000,000
Acquisitions	0
Foreign currency translation	(1,000,000)
Ending Balance	57,000,000
Insulation
Goodwill [Roll Forward]
Beginning Balance	1,049,000,000
Acquisitions	494,000,000
Foreign currency translation	(48,000,000)
Ending Balance	1,495,000,000
Roofing
Goodwill [Roll Forward]
Beginning Balance	400,000,000
Acquisitions	0
Foreign currency translation	(3,000,000)
Ending Balance	397,000,000
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	363,000,000
Acquisitions	215,000,000
Other additions, net	0
Foreign currency translation	24,000,000
Ending Balance	554,000,000
Technology-Based Intangible Assets
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	255,000,000
Acquisitions	73,000,000
Other additions, net	0
Foreign currency translation	7,000,000
Ending Balance	321,000,000
Trademarks
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	946,000,000
Acquisitions	213,000,000
Other additions, net	0
Foreign currency translation	15,000,000
Ending Balance	1,144,000,000
Other
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	47,000,000
Acquisitions	7,000,000
Other additions, net	8,000,000
Foreign currency translation	2,000,000
Ending Balance	$ 60,000,000

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT (DETAIL) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	$ 6,386	$ 5,756
Accumulated depreciation	(2,575)	(2,331)
Property, plant and equipment, net	$ 3,811	$ 3,425
Precious metals percentage	11.00%	12.00%
Precious metals depletion, percentage	3.00%
Land
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	$ 224	$ 251
Buildings and Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	1,091	944
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	4,628	4,211
Construction in Progress
Property Plant And Equipment [Line Items]
Property, plant, and equipment, gross	$ 443	$ 350

ACQUISITIONS (DETAIL)

ACQUISITIONS (DETAIL) - USD ($)	Feb. 05, 2018	Jun. 27, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Payments			$ 1,147,000,000
Payments			1,143,000,000	$ 570,000,000	$ 452,000,000
Finite-lived intangible assets			508,000,000
Revenues			7,057,000,000	6,384,000,000	5,677,000,000
Cost of sales			5,425,000,000	$ 4,815,000,000	$ 4,300,000,000
Acquisitions			494,000,000
Paroc Group
Business Acquisition [Line Items]
Payments	$ 1,121,000,000
Finite-lived intangible assets			508,000,000
Revenues			462,000,000
Cost of sales			2,000,000
Property, plant, and equipment			305,000,000
Deferred tax liabilities			99,000,000
Acquisitions			476,000,000
Cash acquired from acquisition			17,000,000
Pittsburgh Corning
Business Acquisition [Line Items]
Payments		$ 563,000,000
Finite-lived intangible assets			245,000,000
Acquisitions			154,000,000
Cash acquired from acquisition			52,000,000
Revenue			128,000,000
Goodwill, expected tax deductible amount			$ 0
Customer Relationships
Business Acquisition [Line Items]
Weighted Average Useful Life			20 years	20 years
Customer Relationships | Paroc Group
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 215,000,000
Weighted Average Useful Life			20 years
Customer Relationships | Pittsburgh Corning
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 107,000,000
Weighted Average Useful Life			19 years
Technology - Know-how | Paroc Group
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 61,000,000
Weighted Average Useful Life			15 years
Technology - Patented | Paroc Group
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 12,000,000
Weighted Average Useful Life			5 years
Quarry Rights | Paroc Group
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 7,000,000
Weighted Average Useful Life			45 years
Trademarks | Paroc Group
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 213,000,000
Trademarks | Pittsburgh Corning
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 101,000,000
Technology
Business Acquisition [Line Items]
Weighted Average Useful Life			17 years	18 years
Technology | Pittsburgh Corning
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 37,000,000
Weighted Average Useful Life			15 years

OPERATING LEASES (DETAIL)

OPERATING LEASES (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OperatingLeasesFutureMinimumPaymentsDueAbstract
Operating lease rent expense	$ 106	$ 87	$ 79
2,019	83
2,020	64
2,021	47
2,022	31
2,023	18
2024 and beyond	$ 27

TOTAL CURRENT LIABILITIES (DETA

TOTAL CURRENT LIABILITIES (DETAIL) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable	$ 851	$ 834
Payroll, vacation pay and incentive compensation	157	198
Payroll, property and other taxes	43	71
Other	227	179
Accounts payable and accrued liabilities	$ 1,278	$ 1,282

WARRANTIES (DETAIL)

WARRANTIES (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Movement In Standard And Extended Product Warranty Increase Decrease [Roll Forward]
Product warranty accrual, beginning balance	$ 55	$ 52
Amounts accrued for current year	20	18
Settlements of warranty claims	(15)	(15)
Product warranty accrual, ending balance	$ 60	$ 55

RESTRUCTURING AND ACQUISITION_3

RESTRUCTURING AND ACQUISITION-RELATED COSTS (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	$ 16	$ 15	$ 9
Charges related to cost reduction actions	22	48	28
Restructuring Reserve Roll Forward
Beginning Balance	20
Restructuring costs	22
Payments	(18)
Non-cash items and reclassifications to other accounts	(7)
Ending Balance	17	20
Cumulative Charges Incurred	68
Employee Severance
Restructuring Reserve Roll Forward
Ending Balance	14
Restructuring reserve, noncurrent	1
Restructuring reserve, current	13
Paroc Group
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	14
Pittsburgh Corning Corporation
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	2
Selling, General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	7
Selling, General and Administrative Expenses | Paroc Group
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	5
Selling, General and Administrative Expenses | Pittsburgh Corning Corporation
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	2
Other Expense
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	9
Other Expense | Employee Severance
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions	4	27	1
Other Expense | Additional Exit Costs
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions	1	1	2
Other Expense | Paroc Group
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	9
Other Expense | Pittsburgh Corning Corporation
Restructuring Cost and Reserve [Line Items]
Acquisition related costs	0
Cost of Sales | Additional Exit Costs
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions	7	3	6
Cost of Sales | Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Charges related to cost reduction actions	10	17	$ 19
Pittsburgh Corning Related Restructuring
Restructuring Reserve Roll Forward
Beginning Balance	9
Restructuring costs	3
Payments	(4)
Non-cash items and reclassifications to other accounts	(1)
Ending Balance	7	9
Cumulative Charges Incurred	20
Pittsburgh Corning Related Restructuring | Employee Severance
Restructuring Reserve Roll Forward
Restructuring costs	2
Pittsburgh Corning Related Restructuring | Accelerated Depreciation
Restructuring Reserve Roll Forward
Accelerated depreciation related to cost reduction actions	1
Cost Reductions Actions 2017
Restructuring Reserve Roll Forward
Beginning Balance	11
Restructuring costs	19
Accelerated depreciation related to cost reduction actions	9
Payments	(14)
Non-cash items and reclassifications to other accounts	(6)
Ending Balance	10	$ 11
Cumulative Charges Incurred	48
Cost Reductions Actions 2017 | Employee Severance
Restructuring Reserve Roll Forward
Restructuring costs	2
Cost Reductions Actions 2017 | Additional Exit Costs
Restructuring Reserve Roll Forward
Restructuring costs	8
Expected cost remaining	$ 8

DEBT (SCHEDULE OF DEBT) (DETAIL

DEBT (SCHEDULE OF DEBT) (DETAIL) - USD ($)		Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt		$ 3,371,000,000	$ 2,409,000,000
Notes Payable, Fair Value Disclosure, Par Value	[1]	100.00%	100.00%
Unamortized interest rate swap basis adjustment		$ 5,000,000	$ 6,000,000
Less – current portion	[1]	9,000,000	4,000,000
Long-term debt, net of current portion		3,362,000,000	2,405,000,000
4.20% senior notes, net of discount and financing fees, due 2022
Debt Instrument [Line Items]
Long-term debt		$ 598,000,000	$ 597,000,000
Notes Payable, Fair Value Disclosure, Par Value		99.00%	105.00%
4.20% senior notes, net of discount and financing fees, due 2024
Debt Instrument [Line Items]
Long-term debt		$ 393,000,000	$ 392,000,000
Notes Payable, Fair Value Disclosure, Par Value		99.00%	105.00%
3.40% senior notes, net of discount and financing fees, due 2026
Debt Instrument [Line Items]
Long-term debt		$ 396,000,000	$ 395,000,000
Notes Payable, Fair Value Disclosure, Par Value		90.00%	98.00%
7.00% senior notes, net of discount and financing fees, due 2036
Debt Instrument [Line Items]
Long-term debt		$ 400,000,000	$ 400,000,000
Notes Payable, Fair Value Disclosure, Par Value		112.00%	132.00%
4.30% 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 Disclosure, Par Value		76.00%	99.00%
4.40% senior notes, net of discount and financing fees, due 2048
Debt Instrument [Line Items]
Long-term debt		$ 389,000,000
Notes Payable, Fair Value Disclosure, Par Value		77.00%
Accounts receivable securitization facility, maturing in 2020 (a)
Debt Instrument [Line Items]
Long-term debt		$ 75,000,000
Notes Payable, Fair Value Disclosure, Par Value		100.00%	0.00%
Various capital leases, due through and beyond 2050
Debt Instrument [Line Items]
Long-term debt	[1]	$ 27,000,000	$ 31,000,000
Notes Payable, Fair Value Disclosure, Par Value	[1]	100.00%	100.00%
Term loan borrowing, maturing in 2021
Debt Instrument [Line Items]
Long-term debt		$ 500,000,000	$ 0
Notes Payable, Fair Value Disclosure, Par Value		100.00%
[1]	The Company determined that the book value of the above noted debt instruments approximates fair value.

DEBT (DETAIL)

DEBT (DETAIL)

Aug. 08, 2016USD ($)

Nov. 12, 2014USD ($)

Oct. 17, 2012USD ($)

Mar. 31, 2018USD ($)

Sep. 30, 2016

Dec. 31, 2018USD ($)

May 04, 2018USD ($)

Apr. 01, 2018USD ($)

Jan. 25, 2018USD ($)

Dec. 31, 2017USD ($)

Oct. 27, 2017USD ($)term_loan

Jun. 26, 2017USD ($)

Mar. 31, 2016

Oct. 31, 2006USD ($)

Long-Term Debt [Line Items]

Borrowing capacity under credit facility

$ 800,000,000

Current maturities

[1]

$ 9,000,000

$ 4,000,000

Short-term Debt [Abstract]

Short-term debt

$ 1,000,000

Term (in years)

1 year

Short term debt, weighted average interest rate

3.00%

6.70%

Senior Note 2048

Long-Term Debt [Line Items]

Face amount

$ 400,000,000

4.30% 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

3.40% 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

Senior Notes Due 2016

Long-Term Debt [Line Items]

Repayments

$ 158,000,000

$ 242,000,000

$ 250,000,000

4.20% 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

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

4.20% 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

Stated rate

0.00%

Term Loan Commitment

Long-Term Debt [Line Items]

Availability on facility

$ 500,000,000

Number of term loan commitments | term_loan

2

Term Loan Commitment One

Long-Term Debt [Line Items]

Borrowing capacity under credit facility

$ 300,000,000

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

$ 600,000,000

$ 600,000,000

Availability on facility

$ 791,000,000

7.00% 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

$ 140,000,000

Letter of Credit Under Receivables Purchase Agreement

Long-Term Debt [Line Items]

Borrowing capacity under credit facility

280,000,000

Availability on facility

202,000,000

Current maturities

$ 250,000,000

280,000,000

$ 280,000,000

Maximum

Short-term Debt [Abstract]

Short-term debt

$ 16,000,000

[1]

The Company determined that the book value of the above noted debt instruments approximates fair value.

DEBT (CREDIT FACILITY UTILIZATI

DEBT (CREDIT FACILITY UTILIZATION) (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	May 04, 2018	Oct. 27, 2017
Debt Instrument [Line Items]
Facility size	$ 800
Senior Revolving Credit Facility B
Debt Instrument [Line Items]
Facility size	800	$ 600	$ 600
Outstanding borrowings	0
Outstanding letters of credit	9
Availability on facility	791
Letter of Credit Under Receivables Purchase Agreement
Debt Instrument [Line Items]
Facility size	280
Collateral capacity limitation on availability	0
Outstanding borrowings	75
Outstanding letters of credit	3
Availability on facility	202
Term Loan Commitment
Debt Instrument [Line Items]
Availability on facility	$ 500

DEBT (SCHEDULE OF DEBT MATURITI

DEBT (SCHEDULE OF DEBT MATURITIES) (DETAIL) $ in Millions	Dec. 31, 2018USD ($)
Maturities of Long-term Debt [Abstract]
2,019	$ 11
2,020	142
2,021	441
2,022	605
2,023	4
2024 and beyond	2,217
Total	$ 3,420

PENSION PLANS (DETAIL)

PENSION PLANS (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Cost of sales	$ 5,425	$ 4,815	$ 4,300
Other expenses, net	36	67	14
Non-operating (income) expense	$ (14)	60	(2)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Pension settlement losses		64
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations, Period	20 years
Defined Benefit Plans, Accumulated Other Comprehensive Income (Loss), After Tax [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations Range Amount	25.00%
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,023				$ 83
Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	$ 1,450	1,578
Service cost	12	12	10
Interest cost	47	55	62
Actuarial gain	(85)	14
Currency loss	(26)	42
Benefits paid	(92)	(71)
Defined Benefit Plan, Settlements / Curtailments	(6)	(213)
Acquisition	11	21
Other	7	12
Benefit Obligation at End of Period	1,318	1,450	1,578
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	1,200	1,215
Actual return on plan assets	(67)	140
Currency gain (loss)	(20)	31
Company contributions	40	72
Benefits paid	(92)	(71)
Settlements/curtailments	(6)	(213)
Acquisition	0	14
Other	0	12
Fair Value of Assets at End of Period	1,055	1,200	1,215
Funded status				(263)	$ (250)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Defined Benefit Plan, Prepaid Pension Cost				7	7
Defined Benefit Plan, Accrued Pension Cost - Current				(2)	(1)
Defined Benefit Plan, Accrued Pension Cost - Noncurrent				(268)	(256)
Defined Benefit Plan, Net Amount Recognized				(263)	(250)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Defined Benefit, Net Actuarial Loss				(484)	(443)
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				1,160	1,281
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Accumulated Benefit Obligation				1,156	1,277
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Fair Value of Plan Assets				896	1,029
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, Projected Benefit Obligation				158	169
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Accumulated Benefit Obligation				140	145
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Fair Value of Plan Assets				159	171
Defined Benefit Plan, Accumulated Benefit Obligation				1,296	1,422
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	12	12	10
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(73)	(79)	(81)
Amortization of actuarial gain	15	18	16
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	0	64	(6)
Other	0	0	2
Net periodic postretirement benefit cost	1	70	3
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	1,200	1,215	1,215	1,055	$ 1,200
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,019				87
2,020				85
2,021				83
2,022				85
2024-2028				398
Pension Plans, Defined Benefit | Other Comprehensive Income
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Interest cost	14
Defined Benefit Plans, Accumulated Other Comprehensive Income (Loss), After Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax				$ (484)
United States
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	490
Fair Value of Assets at End of Period	453	490
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate				4.25%	3.55%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Return on Assets				6.75%	6.75%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	490	490		$ 453	$ 490
Plan assets measured at NAV				727	836
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	171
Fair Value of Assets at End of Period	126	171
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	171	171		126	171
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	319
Fair Value of Assets at End of Period	327	319
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	319	319		327	319
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 | Domestic
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	67
Fair Value of Assets at End of Period	50	67
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	67	67		50	67
United States | Domestic | 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	67
Fair Value of Assets at End of Period	50	67
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	67	67		50	67
United States | Domestic | 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	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 | Domestic | 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 | International
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	78
Fair Value of Assets at End of Period	52	78
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	78	78		52	78
United States | International | 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	78
Fair Value of Assets at End of Period	52	78
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	78	78		52	78
United States | International | 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	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 | International | 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 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	231
Fair Value of Assets at End of Period	236	231
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	231	231		236	231
United States | Corporate bonds | 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	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 | Corporate bonds | 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	231
Fair Value of Assets at End of Period	236	231
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	231	231		236	231
United States | Corporate bonds | 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 | Government Debt
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	88
Fair Value of Assets at End of Period	91	88
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	88	88		91	88
United States | Government Debt | 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	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 | Government Debt | 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	88
Fair Value of Assets at End of Period	91	88
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	88	88		91	88
United States | Government Debt | 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 | Real Estate Investment Trusts
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	26
Fair Value of Assets at End of Period	24	26
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	26	26		24	26
United States | Real Estate Investment Trusts | 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	26
Fair Value of Assets at End of Period	24	26
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	26	26		24	26
United States | Real Estate Investment Trusts | 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	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 | Real Estate Investment Trusts | 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 | Equities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				123	173
United States | Real assets
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				54	51
United States | Fixed income and cash equivalents
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				53	69
United States | Absolute return strategies
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				44	53
United States | Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	993	1,066
Service cost	6	7
Interest cost	34	40
Actuarial gain	(67)	30
Currency loss	0	0
Benefits paid	(75)	(53)
Defined Benefit Plan, Settlements / Curtailments	0	(97)
Acquisition	0	0
Other	0	0
Benefit Obligation at End of Period	891	993	1,066
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	836	822
Actual return on plan assets	(59)	114
Currency gain (loss)	0	0
Company contributions	25	50
Benefits paid	(75)	(53)
Settlements/curtailments	0	(97)
Acquisition	0	0
Other	0	0
Fair Value of Assets at End of Period	727	836	$ 822
Funded status				(164)	(157)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Defined Benefit Plan, Prepaid Pension Cost				0	0
Defined Benefit Plan, Accrued Pension Cost - Current				0	0
Defined Benefit Plan, Accrued Pension Cost - Noncurrent				(164)	(157)
Defined Benefit Plan, Net Amount Recognized				(164)	(157)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Defined Benefit, Net Actuarial Loss				(392)	(357)
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				891	993
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Accumulated Benefit Obligation				891	993
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Fair Value of Plan Assets				727	836
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, Projected Benefit Obligation				0	0
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Accumulated Benefit Obligation				0	0
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Fair Value of Plan Assets				0	0
Defined Benefit Plan, Accumulated Benefit Obligation				891	993
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 6	$ 7
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.55%	3.95%	4.20%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Return on Assets	6.75%	6.75%	7.00%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	$ 836	$ 822	$ 822	727	$ 836
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Percentage of Assets Invested in Equity	33.00%
Percentage of Assets Invested in Real Estate	3.00%
Percentage of Assets Invested in Real Assets	8.00%
Percentage of Assets Invested in Intermediate and Long-term Fixed income Securities	50.00%
Percentage of Assets Invested in Absolute Return Securities	6.00%
Defined Contribution Plan [Abstract]
Estimated Future Employer Contributions in Next Fiscal Year				$ 25
Company Match Regardless of Employee Contribution				2.00%
Cost Recognized Related to Defined Benefit Plans	$ 48	42	38
Foreign Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	79
Fair Value of Assets at End of Period	78	79
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate				3.04%	2.88%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Return on Assets				4.91%	5.22%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase				4.14%	4.29%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	79	79		$ 78	$ 79
Plan assets measured at NAV				328	364
Foreign Plan | 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	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	79
Fair Value of Assets at End of Period	78	79
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	79	79		78	79
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 | Domestic
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	3
Fair Value of Assets at End of Period	4	3
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	3	3		4	3
Foreign Plan | Domestic | 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	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 | Domestic | 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	3
Fair Value of Assets at End of Period	4	3
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	3	3		4	3
Foreign Plan | Domestic | 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 | Cash
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	64
Fair Value of Assets at End of Period	62	64
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	64	64		62	64
Foreign Plan | Cash | 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	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 | Cash | 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	64
Fair Value of Assets at End of Period	62	64
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	64	64		62	64
Foreign Plan | Cash | 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 | Corporate bonds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	12
Fair Value of Assets at End of Period	12	12
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	12	12		12	12
Foreign Plan | Corporate bonds | 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	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 | Corporate bonds | 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	12
Fair Value of Assets at End of Period	12	12
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	12	12		12	12
Foreign Plan | Corporate bonds | 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 | Equities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				41	52
Foreign Plan | Fixed income and cash equivalents
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				109	123
Foreign Plan | Absolute return strategies
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan assets measured at NAV				100	110
Foreign Plan | Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	457	512
Service cost	6	5
Interest cost	13	15
Actuarial gain	(18)	(16)
Currency loss	(26)	42
Benefits paid	(17)	(18)
Defined Benefit Plan, Settlements / Curtailments	(6)	(116)
Acquisition	11	21
Other	7	12
Benefit Obligation at End of Period	427	457	512
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Assets at Beginning of Period	364	393
Actual return on plan assets	(8)	26
Currency gain (loss)	(20)	31
Company contributions	15	22
Benefits paid	(17)	(18)
Settlements/curtailments	(6)	(116)
Acquisition	0	14
Other	0	12
Fair Value of Assets at End of Period	328	364	393
Funded status				(99)	(93)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Defined Benefit Plan, Prepaid Pension Cost				7	7
Defined Benefit Plan, Accrued Pension Cost - Current				(2)	(1)
Defined Benefit Plan, Accrued Pension Cost - Noncurrent				(104)	(99)
Defined Benefit Plan, Net Amount Recognized				(99)	(93)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Defined Benefit, Net Actuarial Loss				(92)	(86)
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				269	288
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Accumulated Benefit Obligation				265	284
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Fair Value of Plan Assets				169	193
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, Projected Benefit Obligation				158	169
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Accumulated Benefit Obligation				140	145
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations, Fair Value of Plan Assets				159	171
Defined Benefit Plan, Accumulated Benefit Obligation				405	429
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	6	5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	$ 0	$ 64	$ 0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.88%	3.14%	3.88%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Return on Assets	5.22%	5.92%	6.23%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	4.29%	4.25%	3.97%
Defined Benefit Plan, Information about Plan Assets [Abstract]
Assets	$ 364	$ 393	$ 393	328	$ 364
Defined Contribution Plan [Abstract]
Estimated Future Employer Contributions in Next Fiscal Year				$ 14
Accounting Standards Update 2017-07
Defined Benefit Plan Disclosure [Line Items]
Cost of sales		4,815	4,300
Other expenses, net		67	14
Non-operating (income) expense		60	(2)
Accounting Standards Update 2017-07 | Previously Reported
Defined Benefit Plan Disclosure [Line Items]
Cost of sales		4,812	4,296
Other expenses, net		130	16
Non-operating (income) expense		0	0
Accounting Standards Update 2017-07 | Restatement Adjustment
Defined Benefit Plan Disclosure [Line Items]
Cost of sales		3	4
Other expenses, net		(63)	(2)
Non-operating (income) expense		$ 60	$ (2)

POSTEMPLOYMENT AND POSTRETIRE_3

POSTEMPLOYMENT AND POSTRETIREMENT BENEFITS OTHER THAN PENSIONS (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,023	$ 83
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	230	$ 225
Service cost	1	2	$ 2
Interest cost	8	9	9
Actuarial gain	(25)	(15)
Currency loss	(1)	1
Plan amendments	(2)	(3)
Benefits paid	(16)	(13)
Acquisition	0	22
Other	0	2
Benefit Obligation at End of Period	195	230	225
Funded status	(195)	(230)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued benefit obligation – current	(17)	(19)
Accrued benefit obligation – non-current	(178)	(211)
Defined Benefit Plan, Net Amount Recognized	(195)	(230)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial loss (gain)	(54)	(35)
Net prior service cost (credit)	(9)	(11)
Net amount recognized	(63)	(46)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	2	2
Amortization of prior service cost	(4)	(4)	(4)
Amortization of actuarial gain	(6)	(3)	(1)
Other	0	0	1
Net periodic postretirement benefit cost	(1)	4	7
Defined Benefit Plan, Effect of One Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	0
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	0
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	4
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	(3)
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,019	18
2,020	18
2,021	17
2,022	17
2,023	16
2024-2028	70
Postemployment Benefits [Abstract]
Postemployment Benefits Liability	12	13
Postemployment Benefits, Period Expense	4	$ 3	2
Other Postretirement Benefit Plans, Defined Benefit | Other Comprehensive Income
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Interest cost	12
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax	$ 63
United States
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.25%	3.55%
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	$ 216	$ 212
Service cost	1	2
Interest cost	8	8
Actuarial gain	(25)	(13)
Currency loss	0	0
Plan amendments	(2)	(3)
Benefits paid	(15)	(12)
Acquisition	0	22
Other	0	0
Benefit Obligation at End of Period	183	216	$ 212
Funded status	(183)	(216)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued benefit obligation – current	(17)	(18)
Accrued benefit obligation – non-current	(166)	(198)
Defined Benefit Plan, Net Amount Recognized	(183)	(216)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial loss (gain)	(49)	(29)
Net prior service cost (credit)	(9)	(12)
Net amount recognized	$ (58)	$ (41)
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.15%	3.45%
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 1	$ 2
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.45%	3.80%	4.00%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Initial rate at end of year	6.75%	6.56%	6.78%
Ultimate rate	5.00%	5.00%	5.00%
Year in which ultimate rate is reached	2,026	2,025	2,025
Foreign Plan
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.04%	2.88%
Foreign Plan | Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Period	$ 14	$ 13
Service cost	0	0
Interest cost	0	1
Actuarial gain	0	(2)
Currency loss	(1)	1
Plan amendments	0	0
Benefits paid	(1)	(1)
Acquisition	0	0
Other	0	2
Benefit Obligation at End of Period	12	14	$ 13
Funded status	(12)	(14)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued benefit obligation – current	0	(1)
Accrued benefit obligation – non-current	(12)	(13)
Defined Benefit Plan, Net Amount Recognized	(12)	(14)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax [Abstract]
Net actuarial loss (gain)	(5)	(6)
Net prior service cost (credit)	0	1
Net amount recognized	$ (5)	$ (5)
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.59%	4.56%
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]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.56%	6.78%	3.80%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Initial rate at end of year	5.40%	5.73%	5.07%
Ultimate rate	5.40%	5.49%	4.70%
Year in which ultimate rate is reached	2,019	2,019	2,019

CONTINGENT LIABILITIES AND OT_2

CONTINGENT LIABILITIES AND OTHER MATTERS (DETAIL) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2018USD ($)site
Unusual or Infrequent Item, or Both [Line Items]
Environmental liability sites | site			22
Environmental liabilities reserve			$ 16
Superfund Sites
Unusual or Infrequent Item, or Both [Line Items]
Environmental liability sites | site			8
Owned or Formerly Owned Sites
Unusual or Infrequent Item, or Both [Line Items]
Environmental liability sites | site			14
Positive Outcome of Litigation
Unusual or Infrequent Item, or Both [Line Items]
Gain related to litigation settlement		$ 30
Other Current Liabilities
Unusual or Infrequent Item, or Both [Line Items]
Environmental liabilities reserve			$ 8
Other Expense | Positive Outcome of Litigation
Unusual or Infrequent Item, or Both [Line Items]
Gain related to litigation settlement	$ 29

STOCK COMPENSATION (DETAIL)

STOCK COMPENSATION (DETAIL) - USD ($) $ / shares in Units, $ in Millions	Feb. 15, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 18, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Outstanding Options		478,875
Outstanding Options, Weighted Average Remaining Contractual Term		4 years
Outstanding Options, Weighted Average Exercise Price		$ 37.18
Number of Exercisable Options		478,875
Exercisable Options, Weighted Average Remaining Contractual Term		4 years
Exercisable Options, Weighted Average Exercise Price		$ 37.18
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Options, Outstanding, Number, Beginning Balance		518,725	975,400	1,953,320
Options, Outstanding, Number, Grants In Period		0	0	0
Options, Outstanding, Number, Options Exercised		(39,100)	(453,425)	(960,570)
Options, Outstanding, Number, Forfeitures In Period		(750)	(3,250)	(11,350)
Options, Outstanding, Number, Expirations In Period		0	0	(6,000)
Options, Outstanding, Number, Ending Balance		478,875	518,725	975,400
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		$ 37.17	$ 35.14	$ 31.09
Options, Outstanding, Grants In Period Weighted Average Exercise Price		0	0	0
Options, Outstanding, Exercises In Period Weighted Average Exercise Price		37.05	32.79	26.90
Options, Outstanding, Forfeitures In Period Weighted Average Exercise Price		37.65	37.65	38.50
Options, Outstanding, Expirations In Period Weighted Average Exercise Price		0	0	30
Options, Outstanding, Weighted Average Exercise Price, End of Period		$ 37.18	$ 37.17	$ 35.14
Stock Plan 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant		3,000,000
Performance Stock Units (PSUs) 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility rate		24.56%
Risk free interest rate		2.22%
Expected term		2 years 11 months
Requisite service period (in years)		3 years
Performance Stock Units (PSUs) 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility rate		26.06%
Risk free interest rate		1.44%
Expected term		2 years 11 months
Requisite service period (in years)		3 years
Performance Stock Units (PSUs) 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility rate		26.55%
Risk free interest rate		0.84%
Expected term		2 years 10 months 28 days
Requisite service period (in years)		3 years
Performance Stock Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense		$ 20	$ 19	$ 16
Weighted average period for recognition of compensation cost		1 year 6 months 24 days
Total unrecognized compensation cost related to restricted stock		$ 14
Grants in period fair value		$ 23	$ 9	$ 3
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonoptions, Number, Beginning Balance		451,148	472,300	431,400
Nonoptions, Number, Grants In Period		171,725	221,050	244,250
Nonoptions, Number, Vested In Period		(212,852)	(219,050)	(186,750)
Nonoptions, Number, Forfeited In Period		(49,044)	(23,152)	(16,600)
Nonoptions, Number, Ending Balance		360,977	451,148	472,300
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		$ 53.96	$ 47.19	$ 44.52
Nonoptions, Weighted Average Fair Value, Grants in Period		94.14	59.71	48.74
Nonoptions, Weighted Average Fair Value, Vested		48.73	43.83	44.43
Nonoptions, Weighted Average Fair Value, Forfeited		60.31	49.50	44.48
Nonoptions, Weighted Average Fair Value, Ending Balance		$ 75.23	$ 53.96	$ 47.19
Internal Based Performance Metric
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)		3 years
Return on invested capital		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]
Award vesting period (in years)		4 years
Options maximum term		10 years
Share-based compensation expense		$ 1	$ 1	$ 2
Intrinsic value of options outstanding		3	28	16
Intrinsic value of options exercisable		3	25	13
Cash received from exercise of stock options		$ 1	15	26
Tax benefit from exercise of stock options			7	9
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period (in years)		4 years
Share-based compensation expense		$ 23	21	19
Weighted average period for recognition of compensation cost		2 years 4 months 25 days
Total unrecognized compensation cost related to restricted stock		$ 36
Grants in period fair value		$ 23	$ 19	$ 15
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonoptions, Number, Beginning Balance		1,752,136	1,800,557	1,707,490
Nonoptions, Number, Grants In Period		365,363	496,021	544,627
Nonoptions, Number, Vested In Period		(558,288)	(477,857)	(398,751)
Nonoptions, Number, Forfeited In Period		(79,837)	(66,585)	(52,809)
Nonoptions, Number, Ending Balance		1,479,374	1,752,136	1,800,557
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		$ 42.40	$ 37.78	$ 35.37
Nonoptions, Weighted Average Fair Value, Grants in Period		84.34	56.60	45.61
Nonoptions, Weighted Average Fair Value, Vested		41.34	38.94	37.55
Nonoptions, Weighted Average Fair Value, Forfeited		54.20	44.90	39.80
Nonoptions, Weighted Average Fair Value, Ending Balance		$ 52.30	$ 42.40	$ 37.78
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant					2,000,000
Total unrecognized compensation cost related to restricted stock		$ 2
Purchase price, percentage of market value					85.00%
Employee emergence equity program expense		$ 4	$ 3	$ 3
Shares purchased by employees		300,000	300,000	200,000
Average price of shares purchased		$ 48.93	$ 48.48	$ 41.99
Employee Stock | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Value of shares purchased by employees	$ 4
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable Options, Weighted Average Exercise Price		13.89
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, 2018	Dec. 31, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ (514)
Ending balance		(656)	$ (514)
Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(183)	(284)
Net investment hedge amounts classified into AOCI, net of tax		14	(24)
(Loss) Gain on foreign currency translation		(137)	125
Other comprehensive (loss), net of tax		(123)	101
Ending balance		(306)	(183)
Pension and Other Postretirement Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(331)	(429)
Net gain reclassified from AOCI to net income	[1]	4	53
Amounts classified into AOCI, net of tax		(23)	45
Other comprehensive (loss), net of tax		(19)	98
Ending balance		(350)	(331)
Hedging Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		0	3
Net gain reclassified from AOCI to net income	[2]	(1)	(1)
Amounts classified into AOCI, net of tax		1	(2)
Other comprehensive (loss), net of tax		0	(3)
Ending balance		$ 0	$ 0
[1]	These AOCI components are included in the computation of total Pension and OPEB expense and are recorded in Cost of sales, marketing and administrative expenses and Other expenses, net. See Notes 14 and 15 for additional information.
[2]	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. See Note 5 for additional information.

EARNINGS PER SHARE (DETAIL)

EARNINGS PER SHARE (DETAIL) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
NET EARNINGS ATTRIBUTABLE TO OWENS CORNING	$ 171	$ 161	$ 121	$ 92	$ (4)	$ 96	$ 96	$ 101	$ 545	$ 289	$ 393
Weighted-average number of shares outstanding used for basic earnings per share									110.4	111.5	114.4
Non-vested restricted and performance shares									0.8	1.5	0.8
Options to purchase common stock									0.2	0.2	0.2
Weighted-average number of shares outstanding and common equivalent shares used for diluted earnings per share										113.2	115.4
Basic (dollars per share)	$ 1.56	$ 1.46	$ 1.09	$ 0.83	$ (0.04)	$ 0.86	$ 0.86	$ 0.90	$ 4.94	$ 2.59	$ 3.44
Diluted (dollars per share)	$ 1.55	$ 1.45	$ 1.08	$ 0.82	$ (0.04)	$ 0.85	$ 0.85	$ 0.89	$ 4.89	$ 2.55	$ 3.41

EARNINGS PER SHARE - Narrative

EARNINGS PER SHARE - Narrative (DETAIL) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 24, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Payments for repurchase of equity	$ 203
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	100,000	100,000
Stock Options
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
Remaining number of shares authorized to be repurchased	4,600,000
Combined Repurchase Programs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Purchase of treasury stock (in shares)	2,900,000

INCOME TAXES (DETAIL)

INCOME TAXES (DETAIL) - USD ($)		Dec. 18, 2018	Dec. 31, 2017	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jun. 27, 2017
Operating Loss Carryforwards [Line Items]
Earnings Before Taxes, Domestic																$ 411,000,000	$ 342,000,000	$ 281,000,000
Earnings Before Taxes, Foreign																293,000,000	217,000,000	309,000,000
EARNINGS BEFORE TAXES																704,000,000	559,000,000	590,000,000
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)																(10,000,000)	(2,000,000)	(7,000,000)
Current State and Local Tax Expense (Benefit)																6,000,000	5,000,000	4,000,000
Current Foreign Tax Expense (Benefit)																19,000,000	83,000,000	55,000,000
Current Income Tax Expense (Benefit)																15,000,000	86,000,000	52,000,000
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred Federal Income Tax Expense (Benefit)																114,000,000	196,000,000	117,000,000
Deferred State and Local Income Tax Expense (Benefit)																12,000,000	3,000,000	8,000,000
Deferred Foreign Income Tax Expense (Benefit)																15,000,000	(16,000,000)	11,000,000
Deferred Income Tax Expense (Benefit)																141,000,000	183,000,000	136,000,000
Total income tax expense				$ 29,000,000	[1]	$ 67,000,000		$ 49,000,000		$ 11,000,000	[1]	$ 127,000,000	$ 32,000,000	$ 67,000,000	$ 43,000,000	$ 156,000,000	$ 269,000,000	$ 188,000,000
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
United States federal statutory rate																21.00%	35.00%	35.00%
State and local income taxes, net of federal tax benefit																2.00%	2.00%	2.00%
Foreign tax rate differential																0.00%	(5.00%)	(4.00%)
U.S. tax expense on foreign earnings																2.00%	49.00%	2.00%
Legislative tax rate changes																0.00%	(9.00%)	1.00%
Foreign tax credits																0.00%	29.00%	0.00%
Valuation allowance																2.00%	3.00%	(3.00%)
Uncertain tax positions and settlements																(5.00%)	1.00%	1.00%
Excess tax benefits related to stock compensation																(2.00%)	(1.00%)	(1.00%)
Other, net																2.00%	2.00%	(1.00%)
Effective tax rate																22.00%	48.00%	32.00%
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Other Employee Benefits			$ 92,000,000	87,000,000								92,000,000				$ 87,000,000	$ 92,000,000
Deferred Tax Assets, Pension Plans			48,000,000	66,000,000								48,000,000				66,000,000	48,000,000
Deferred Tax Assets, Operating Loss Carryforwards			377,000,000	255,000,000								377,000,000				255,000,000	377,000,000
Deferred Tax Assets, Operating Loss Carryforwards, Foreign				161,000,000												161,000,000
Deferred Tax Assets, State and Local			3,000,000	3,000,000								3,000,000				3,000,000	3,000,000
Deferred Tax Assets, Other			69,000,000	61,000,000								69,000,000				61,000,000	69,000,000
Deferred Tax Assets, Gross			749,000,000	633,000,000								749,000,000				633,000,000	749,000,000
Valuation Allowance, Amount			94,000,000	78,000,000								94,000,000				78,000,000	94,000,000
Deferred Tax Assets Total			655,000,000	555,000,000								655,000,000				555,000,000	655,000,000
Components of Deferred Tax Liabilities [Abstract]
Deferred Tax Liabilities, Depreciation			234,000,000	259,000,000								234,000,000				259,000,000	234,000,000
Deferred Tax Liabilities, Amortization			314,000,000	395,000,000								314,000,000				395,000,000	314,000,000
Deferred Tax Liabilities Total			548,000,000	654,000,000								548,000,000				654,000,000	548,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Provisional charge			82,000,000													9,000,000
Undistributed earnings of foreign subsidiaries				1,400,000,000												1,400,000,000
U.S. federal loss carryforwards				65,000,000												65,000,000
U.S. state loss carryforwards	[2]			58,000,000												58,000,000
Foreign loss and tax credit carryforwards				37,000,000												37,000,000
Foreign loss and tax credit carryforwards	[2]			65,000,000												65,000,000
U.S foreign tax credits				161,000,000												161,000,000
Other U.S. federal and state tax credits				30,000,000												30,000,000
US State Deferred Tax Asset Related to Loss Carryforwards Set to Expire				8,000,000												8,000,000
Foreign Deferred Tax Asset Related to Loss Carryforwards Set to Expire				6,000,000												$ 6,000,000
Operating Loss Carryforwards Expiration Period																3 years
Federal Earnings Before Tax Needed																$ 1,300,000,000
State Earnings Before Tax Needed																1,900,000,000
Foreign Earnings Before Tax Needed																400,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits, Beginning Balance										$ 90,000,000					$ 98,000,000	90,000,000	98,000,000	$ 84,000,000
Tax Positions Related to Current Year, Gross Additions																6,000,000	1,000,000	1,000,000
Tax Positions Related to Prior Years, Gross Additions																36,000,000	13,000,000	19,000,000
Tax Positions Related to Prior Years, Gross Reductions																(37,000,000)	(11,000,000)	(5,000,000)
Settlements		$ (32,000,000)														(5,000,000)	(12,000,000)	(1,000,000)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations																(4,000,000)	0	0
Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation																(2,000,000)
Unrecognized Tax Benefits, Increase Resulting from Foreign Currency Translation																	1,000,000	0
Unrecognized Tax Benefits, Ending Balance			90,000,000	84,000,000								90,000,000				84,000,000	90,000,000	98,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate				65,000,000												65,000,000
Income Tax Penalties and Interest [Abstract]
Income Tax Examination, Penalties and Interest Accrued			$ 11,000,000	10,000,000								$ 11,000,000				10,000,000	11,000,000	11,000,000
Income Tax Examination, Penalties and Interest Expense																1,000,000	1,000,000	$ (1,000,000)
Minimum
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Unrecognized Tax Benefits Estimated Range of Change Lower Bound				0												0
Maximum
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Unrecognized Tax Benefits Estimated Range of Change Lower Bound				3,000,000												3,000,000
Domestic Tax Authority
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Gross				11,000,000												11,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				400,000,000												400,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Tax Positions Related to Current Year, Gross Additions																34,000,000	24,000,000
Domestic Tax Authority | Minimum
Components of Deferred Tax Assets [Abstract]
Valuation Allowance, Amount				0												0
Domestic Tax Authority | Maximum
Components of Deferred Tax Assets [Abstract]
Valuation Allowance, Amount				1,000,000												1,000,000
State and Local Jurisdiction
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Gross				18,000,000												18,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				1,600,000,000												1,600,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Tax Positions Related to Current Year, Gross Additions																6,000,000	1,000,000
Foreign Tax Authority
Components of Deferred Tax Assets [Abstract]
Deferred Tax Assets, Gross				50,000,000												50,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				400,000,000												400,000,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Tax Positions Related to Current Year, Gross Additions																38,000,000	$ 69,000,000
Pittsburgh Corning Corporation
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards [Abstract]
Operating Loss Carryforwards				$ 192,000,000												$ 192,000,000				$ 296,000,000
Other Assets | Accounting Standards Update 2016-16
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Cumulative effect adjustment																			$ 17,000,000
Deferred Income Tax Assets | Accounting Standards Update 2016-16
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Cumulative effect adjustment																			7,000,000
Accumulated Earnings | Accounting Standards Update 2016-16
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Cumulative effect adjustment																			$ 10,000,000
[1]	Income tax expense for the fourth quarter of 2017 includes a provisional charge of $82 million related to the Tax Act. Please refer to Note 20 for additional details on this charge.
[2]	As of December 31, 2018, $8 million of U.S. state and $6 million of foreign deferred tax assets related to loss carryforwards are set to expire over the next three years.

QUARTERLY FINANCIAL INFORMATI_3

QUARTERLY FINANCIAL INFORMATION (unaudited) (DETAIL) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effect of Fourth Quarter Events [Line Items]
NET SALES	$ 1,724		$ 1,818		$ 1,824		$ 1,691		$ 1,606	$ 1,703	$ 1,597	$ 1,478	$ 7,057	$ 6,384	$ 5,677
Gross margin	411		448		418		355		396	423	408	342	1,632	1,569	1,377
Income tax expense	29	[1]	67	[1]	49	[1]	11	[1]	127	32	67	43	156	269	188
Net earnings attributable to Owens Corning	$ 171		$ 161		$ 121		$ 92		$ (4)	$ 96	$ 96	$ 101	$ 545	$ 289	$ 393
Basic (dollars per share)	$ 1.56		$ 1.46		$ 1.09		$ 0.83		$ (0.04)	$ 0.86	$ 0.86	$ 0.90	$ 4.94	$ 2.59	$ 3.44
Diluted (dollars per share)	$ 1.55		$ 1.45		$ 1.08		$ 0.82		$ (0.04)	$ 0.85	$ 0.85	$ 0.89	$ 4.89	$ 2.55	$ 3.41
Accounting Standards Update 2017-07
Effect of Fourth Quarter Events [Line Items]
Gross margin												$ 1
Accounting Standards Update 2018-02
Effect of Fourth Quarter Events [Line Items]
Income tax expense									$ 82
[1]	Income tax expense for the fourth quarter of 2017 includes a provisional charge of $82 million related to the Tax Act. Please refer to Note 20 for additional details on this charge.

SCHEDULE II - VALUATION AND Q_2

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (DETAIL) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 19	$ 9	$ 8
Charged to Costs and Expenses		0	12	2
Charged to Other Accounts		0	0	0
Deductions	[1]	(4)	(2)	(1)
Acquisitions and Divestitures		1	0	0
Balance at End of Period		16	19	9
Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		94	103	135
Charged to Costs and Expenses		13	9	(27)
Charged to Other Accounts		(4)	7	(5)
Deductions		(31)	(25)	0
Acquisitions and Divestitures		6	0	0
Balance at End of Period		$ 78	$ 94	$ 103
[1]	Uncollectible accounts written off, net of recoveries.