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Fair Value of Assets and Liabilities - Narrative (Details) - Corporate $ in Millions | 3 Months Ended
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Mar. 31, 2021 USD ($)
Segment Reporting Information [Line Items] |
Fixed asset impairments | $ 33
Asset impairment charges | 33
Disposition of Acquired Properties | 2019 Business Optimization |
Segment Reporting Information [Line Items] |
Asset impairment charges | $ 3

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