Revenue Recognition (Allowance for Doubtful Accounts Rollforward) (Details) - Allowance for credit losses - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 134	$ 112	$ 108
Charged to Costs and Expenses	14	11	5
Charged to Revenue	60	49	31
Deductions and other	(39)	(38)	(32)
Ending balance	$ 169	$ 134	$ 112