Credit Losses on Financial Instruments (Details) $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 38
Provision for expected losses	16
Write-offs charged against the allowance	(24)
Financing Receivable, Allowance for Credit Loss, Recovery	1
Ending balance	31
Mass Market Portfolio
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	19
Provision for expected losses	9
Write-offs charged against the allowance	(16)
Financing Receivable, Allowance for Credit Loss, Recovery	0
Ending balance	12
Business Portfolio
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	19
Provision for expected losses	7
Write-offs charged against the allowance	(8)
Financing Receivable, Allowance for Credit Loss, Recovery	1
Ending balance	$ 19