BUSINESS SEGMENT INFORMATION Operating Profit by Industry Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Sales	$ 6,222	$ 3,979	$ 17,628	$ 11,913
Cost of products sold	4,287	2,880	12,514	8,632
Selling and administrative expenses	493	473	1,505	1,222
Depreciation and amortization	1,099	208	2,050	630
Distribution expenses	524	288	1,457	901
Interest Expense, net	85	52	277	156
Adjustment for less than wholly owned subsidiaries	(1)	(1)	(2)	(4)
Corporate expenses, net	17	40	74	144
Net special items	354	113	611	186
Non-operating pension expense (income)	(4)	(12)	(6)	(34)
Earnings (Loss) From Continuing Operations Before Income Taxes and Equity Earnings (Loss)	(675)	5	(714)	256
Asset impairment	31		31
Other nonrecurring (income) expense	55		69
Restructuring charges, net	342	55	464	58
Gain on disposition of business	(16)	0	35	0
Gain on sale of fixed assets	(15)	0	52	0
EMEA Plants
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gain on disposition of business			51
Savannah Containerboard Mill
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Business exit costs	135		135
Riceboro Containerboard Mill
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Business exit costs	95		95
Red River Containerboard Mill
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Restructuring charges, net			85
Orange, Texas Containerboard Mill
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gain on sale of fixed assets			67
DS Smith Plc
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Business combination, transactions costs	38		314
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Sales	6,208	3,962	17,611	11,752
Business Segment Operating Profit (Loss)	(224)	197	240	704
Corporate and Intrasegment Sales
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Sales	14	17	17	161
Packaging Solutions North America | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Sales	3,898	3,640	11,460	10,754
Cost of products sold	2,582	2,605	7,846	7,631
Selling and administrative expenses	335	360	957	960
Depreciation and amortization	831	192	1,480	581
Distribution expenses	287	265	834	834
Other segment items	29	28	90	85
Business Segment Operating Profit (Loss)	(166)	190	253	663
Packaging Solutions EMEA | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Sales	2,310	322	6,151	998
Cost of products sold	1,721	246	4,567	758
Selling and administrative expenses	134	29	381	79
Depreciation and amortization	267	16	569	48
Distribution expenses	235	23	621	68
Other segment items	11	1	26	4
Business Segment Operating Profit (Loss)	$ (58)	$ 7	$ (13)	$ 41