Stock Compensation (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Benefits and Share-based Compensation	$ 8	$ 4	$ 23	$ 13
APIC, Share-based Payment Arrangement, Increase for Cost Recognition		$ 4
Additional Paid-in Capital [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Benefits and Share-based Compensation	$ 8		$ 23	$ 13

Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 20
-Section 55
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration