SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION - Inventories (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 69	$ 56
Finished paper and pulp products	217	178
Operating supplies	122	107
Other	10	20
Total	$ 418	361
Inventory, LIFO reserve percentage	47.00%
Last-in, first-out inventory reserve	$ 55	72
Effect of LIFO Inventory Liquidation on Income	$ 12	$ 12