Income Taxes: (Schedule of Temporary Differences of Tax Effects to Deferred Income Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deferred income tax assets:
Accrued postretirement and postemployment benefits	$ 227	$ 208
Accrued pension costs	189	384
Inventory	47	40
Accrued liabilities	212	213
Net operating loss, tax credit, and other carryforwards	1,542	912
Investments in equity interests	810	507
Foreign exchange	451	0
Other	325	62
Total deferred income tax assets	3,803	2,326
Less: valuation allowance	(1,709)	(1,130)
Deferred income tax assets, net of valuation allowance	2,094	1,196
Deferred income tax liabilities:
Intangible assets	(1,936)	(1,862)
Property, plant and equipment	(165)	(152)
Unremitted earnings	(811)	(495)
Foreign exchange	0	(264)
Other	0	0
Total deferred income tax liabilities	(2,912)	(2,773)
Net deferred income tax assets (liabilities)	$ (818)	$ (1,577)