Credit Losses on Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2024

Credit Loss [Abstract]

Financing Receivable, Allowance for Credit Loss

The following table presents the activity of our allowance for credit losses by accounts receivable portfolio for the three months ended March 31, 2024:

	Business		Mass Markets	Total
	(Dollars in millions)
As of December 31, 2023	$	14	20	34
Provision for expected losses	8		12	20
Write-offs charged against the allowance	(5)		(12)	(17)
Recoveries collected	—		1	1
Ending balance at March 31, 2024	$	17	21	38