Credit Losses on Financial Instruments (Details) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 67
Provision for expected losses	54
Write-offs charged against the allowance	(69)
Recoveries collected	8
Ending balance	60
Business
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	36
Provision for expected losses	19
Write-offs charged against the allowance	(26)
Recoveries collected	5
Ending balance	34
Mass Markets
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	31
Provision for expected losses	35
Write-offs charged against the allowance	(43)
Recoveries collected	3
Ending balance	$ 26