Long-term Financing and Sales of Receivables - Credit Quality of Long-Term Receivables and Allowance for Credit Losses (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total Long-term Receivable	$ 49	$ 76
Financing receivables	20	19
Financial Asset, Not Past Due
Debt Instrument [Line Items]
Financing receivables	1	2
Past Due Under 90 Days
Debt Instrument [Line Items]
Financing receivables	0	1
Past Due Over 90 Days
Debt Instrument [Line Items]
Financing receivables	2	4
Municipal leases secured tax exempt
Debt Instrument [Line Items]
Total Long-term Receivable	28	50
Municipal leases secured tax exempt | Financial Asset, Not Past Due
Debt Instrument [Line Items]
Financing receivables	0	0
Municipal leases secured tax exempt | Past Due Under 90 Days
Debt Instrument [Line Items]
Financing receivables	0	0
Municipal leases secured tax exempt | Past Due Over 90 Days
Debt Instrument [Line Items]
Financing receivables	0	0
Commercial loans and leases secured
Debt Instrument [Line Items]
Total Long-term Receivable	21	26
Commercial loans and leases secured | Financial Asset, Not Past Due
Debt Instrument [Line Items]
Financing receivables	1	2
Commercial loans and leases secured | Past Due Under 90 Days
Debt Instrument [Line Items]
Financing receivables	0	1
Commercial loans and leases secured | Past Due Over 90 Days
Debt Instrument [Line Items]
Financing receivables	$ 2	$ 4