Future Policy Benefits - FBP - Additional Insurance Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 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	(2)	1
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change	1,379	1,596
Additional Liability, Long-Duration Insurance, Assessment Accrual	(1)	(1)
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	5	6
Additional Liability, Long-Duration Insurance, Benefit Payment	(10)	(12)
Additional Liability, Long-Duration Insurance, Effect of Foreign Currency Translation	(11)	(82)
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	1,362	1,507
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	$ 1,362	$ 1,507
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	(3)	(13)
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change	485	586
Additional Liability, Long-Duration Insurance, Assessment Accrual	(1)	0
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	2	2
Additional Liability, Long-Duration Insurance, Benefit Payment	0	0
Additional Liability, Long-Duration Insurance, Effect of Foreign Currency Translation	(5)	(30)
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	481	558
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	(23)	10
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	$ 458	$ 568
Additional Liability, Long-Duration Insurance, Weighted-Average Duration	42 years	41 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	11	14
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change	2,230	2,064
Additional Liability, Long-Duration Insurance, Assessment Accrual	28	27
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	30	28
Additional Liability, Long-Duration Insurance, Benefit Payment	(40)	(39)
Additional Liability, Long-Duration Insurance, Balance, before AOCI adjustment	2,248	2,080
Additional Liability, Long-Duration Insurance, Original Discount Rate, AOCI Adjustment before Cash Flow and Reinsurance	(50)	14
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	2,198	2,094
Additional Liability, Long-Duration Insurance, Reinsurance Recoverable, after Allowance	748	745
Additional Liability, Long-Duration Insurance, after Reinsurance	$ 1,450	$ 1,349
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%