Credit Losses on Financial Instruments (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 38
Provision for expected losses	7
Write-offs charged against the allowance	(9)
Ending balance	36
Mass Market Portfolio
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	19
Provision for expected losses	4
Write-offs charged against the allowance	(6)
Ending balance	17
Business Portfolio
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	19
Provision for expected losses	3
Write-offs charged against the allowance	(3)
Ending balance	$ 19