Fair Value Measurements Level 4 Fair Value Option (Details) $ in Millions	Dec. 31, 2019 USD ($)
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Fixed Maturity Securities	$ 6

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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