DISCONTINUED OPERATIONS - Net Earnings (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS ATTRIBUTABLE TO OWENS CORNING, NET OF TAX	$ (84)	$ 29	$ (227)	$ (319)
Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	114	306	426	576
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	92	230	340	434
Disposal Group, Including Discontinued Operation, General and Administrative Expense	7	18	27	35
Disposal Group, Including Discontinued Operation, Loss from classification as held for sale	(7)	19	175	381
Disposal Group, Including Discontinued Operation, Other Expense (Income), Net	0	3	6	5
Total operating expenses	0	40	208	421
Disposal Group, Including Discontinued Operation, Interest Expense	0	1	0	2
Disposal Group, Including Discontinued Operation, Income Tax Expense (Benefit)	106	6	105	38
NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS ATTRIBUTABLE TO OWENS CORNING, NET OF TAX	$ (84)	$ 29	$ (227)	$ (319)

Disposal Group, Including Discontinued Operation, Income Tax Expense (Benefit)

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Disposal Group, Including Discontinued Operation, Loss from classification as held for sale

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Disposal Group, Including Discontinued Operation, Other Expense (Income), Net

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Amount of costs of goods sold attributable to disposal group, including, but not limited to, discontinued operation.

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Amount of general and administrative expense attributable to disposal group, including, but not limited to, discontinued operation.

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Amount of interest expense attributable to disposal group, including, but not limited to, discontinued operation.

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Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

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Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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