Future Policy Benefits - FBP - Additional Insurance Liabilities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Variable Life | Asia
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	$ 1,381	$ 1,595
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	0	0
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	1,381	1,595
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) of Actual Variance from Expected Experience	(8)	1
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change	1,373	1,596
Additional Liability, Long-Duration Insurance, Assessment Accrual	(2)	(2)
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	10	11
Additional Liability, Long-Duration Insurance, Benefit Payment	(19)	(20)
Additional Liability, Long-Duration Insurance, Effect of Foreign Currency Translation	(119)	(241)
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	1,243	1,344
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	0	0
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	$ 1,243	$ 1,344
Additional Liability, Long-Duration Insurance, Weighted-Average Duration	17 years	18 years
Additional Liability, Long-Duration Insurance, Weighted-Average Interest Accretion Rate	1.50%	1.50%
Universal And Variable Life Contracts [Member] | Asia
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	$ 455	$ 655
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	(33)	56
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	488	599
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) of Actual Variance from Expected Experience	(22)	(41)
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change	466	558
Additional Liability, Long-Duration Insurance, Assessment Accrual	0	0
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	3	4
Additional Liability, Long-Duration Insurance, Benefit Payment	0	0
Additional Liability, Long-Duration Insurance, Effect of Foreign Currency Translation	(41)	(89)
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	428	473
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	(18)	(19)
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	$ 410	$ 454
Additional Liability, Long-Duration Insurance, Weighted-Average Duration	43 years	42 years
Additional Liability, Long-Duration Insurance, Weighted-Average Interest Accretion Rate	1.50%	1.50%
Universal And Variable Life Contracts [Member] | MetLife Holdings
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	$ 2,156	$ 2,117
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	(63)	67
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	2,219	2,050
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) of Actual Variance from Expected Experience	(6)	19
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change	2,213	2,069
Additional Liability, Long-Duration Insurance, Assessment Accrual	55	53
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	61	56
Additional Liability, Long-Duration Insurance, Benefit Payment	(63)	(62)
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	2,266	2,116
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	2	(35)
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	2,268	2,081
Additional Liability, Long-Duration Insurance, Reinsurance Recoverable, after Allowance	744	753
Additional Liability, Long-Duration Insurance, after Reinsurance	$ 1,524	$ 1,328
Additional Liability, Long-Duration Insurance, Weighted-Average Duration	16 years	16 years
Additional Liability, Long-Duration Insurance, Weighted-Average Interest Accretion Rate	5.60%	5.50%