Sales Of Receivables (Summary of Receivables Sold) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net cash received from equipment installment receivables	$ 396	$ 757	$ 1,080	$ 2,179
Equipment Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net cash received from equipment installment receivables	293	450	233	1,543
Cash proceeds received	2,937	2,664	8,122	8,598
Other Sales of Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net cash received from equipment installment receivables	103	$ 307	847	$ 636
Asset Pledged as Collateral without Right
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Fair Value Disclosure	$ 823		$ 823