Supplementary Financial Information - Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Supplemental Financial Information [Line Items]
Total Restricted Cash	$ 69	$ 66
Other Current Assets
Supplemental Financial Information [Line Items]
Restricted cash	33	23
Other Long-term Assets
Supplemental Financial Information [Line Items]
Restricted cash	$ 36	$ 43

Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Name:	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant