10-K Property And Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 7,119	$ 8,259
Accumulated depreciation and amortization		(2,803)	(4,340)
Property and equipment, net	$ 4,248	4,316	3,919
Computer Software, Purchased and Internally Developed [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		5,604	6,115
Data Processing Equipment And Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		828	1,314
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		648	641
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		38	172
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 1	$ 17