Investment Holding Level 4 Investment Income (Details) - USD ($) $ in Millions	5 Months Ended	7 Months Ended	12 Months Ended
May 31, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Net Investment Income [Line Items]
Investment Income, Investment Expense	$ (19)	$ (18)	$ (26)	$ (24)
Net investment income	520	509	816	924
Fixed Maturities [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	395	343	518	586
Equity Securities [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	4	9	7	6
Mortgage loans [1]
Net Investment Income [Line Items]
Gross Investment Income, Operating	54	49	92	92
Policy loans
Net Investment Income [Line Items]
Gross Investment Income, Operating	32	48	82	84
Limited Partnerships and Other Alternative Investments [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	41	67	130	161
Other Investments [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	$ 13	$ 11	$ 13	$ 19

Amount, before investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 220
-Section S99
-Paragraph 1
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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