Financial Instruments: (Qualifying Hedging Activity Reported in Accumulated Other Comprehensive Earnings (Losses) Net of Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ (9,870)	$ (9,446)	$ (6,311)
Ending balance	(8,028)	(9,870)	(9,446)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	467	241	266
Derivative (gains)/losses transferred to earnings	(94)	(213)	(220)
Change in fair value	(89)	439	195
Ending balance	$ 284	$ 467	$ 241