Credit Losses on Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 61	$ 35
Provision for expected losses	27	66
Write-offs charged against the allowance	(54)	(48)
Recoveries collected	4	8
Ending balance	38	61
Previously Reported
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	61
Ending balance		61
Mass Market Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	19
Consumer | Previously Reported
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	32
Ending balance		32
Consumer | Revision of Prior Period, Reclassification, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(32)
Ending balance		(32)
Business Segment | Previously Reported
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	29
Ending balance		29
Business Segment | Revision of Prior Period, Reclassification, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(4)
Ending balance		(4)
Business
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		17
Provision for expected losses		30
Write-offs charged against the allowance		(22)
Recoveries collected		4
Mass Markets
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		18
Provision for expected losses		36
Write-offs charged against the allowance		(26)
Recoveries collected		4
Business
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	25
Provision for expected losses	10
Write-offs charged against the allowance	(19)
Recoveries collected	3
Ending balance	19	25
Mass Market Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	36
Provision for expected losses	17
Write-offs charged against the allowance	(35)
Recoveries collected	$ 1
Ending balance		$ 36