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Stock-Based Compensation - Schedule of PSU Activity (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Related tax benefit realized | $ 5 | $ 3 | $ 12 | $ 16
PSUs |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
PSUs vested (in shares) |  |  | 78,727 | 235,935
Common Stock issued net of tax withholding (in shares) |  |  | 49,967 | 156,450
Related tax benefit realized |  |  | $ 1 | $ 7

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- Definition Amount of tax benefit from exercise of option under share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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