Income Taxes: (Schedule of Earnings Before Income Taxes and Provision For Income Taxes, Current Year) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Earnings before income taxes
United States	$ 870
Foreign	13,010
Earnings before income taxes	13,880	$ 12,199	$ 10,450
Current tax expense (benefit)
U.S. Federal	371	465	201
U.S. State and Local	31
Foreign	3,182	2,668	2,468
Total current tax expense (benefit)	3,584
Deferred tax expense (benefit)
U.S. Federal	(817)	(81)	(368)
U.S. State and Local	(40)
Foreign	10	(35)	38
Total deferred tax expense (benefit)	(847)	(123)	(330)
Total provision for income taxes	$ 2,737	$ 3,017	$ 2,339