Fair Value of Assets and Liabilities - Narrative (Details) - Corporate $ in Millions	3 Months Ended
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

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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The charge against earnings resulting from the aggregate write down of tangible assets from their carrying value to their fair value.

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