Restructuring Charges (Summary of Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Restructuring Cost and Reserve [Line Items]
Severance (including payroll taxes)	$ 1
Workforce Reduction
Restructuring Cost and Reserve [Line Items]
Severance (including payroll taxes)	$ 0	$ 6

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Name:	us-gaap_SeveranceCosts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration