Credit Losses on Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2022

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, 2022:

	Business		Mass Markets	Total
	(Dollars in millions)
As of December 31, 2021	$	19	19	38
Provision for expected losses	3		4	7
Write-offs charged against the allowance	(3)		(6)	(9)
Ending balance at March 31, 2022	$	19	17	36