Future Policy Benefits - FPB - Additional Insurance Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Variable Life | Asia
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Balance, beginning of period	$ 1,381	$ 1,595
Less: AOCI adjustment	0	0
Balance, beginning of period, before AOCI adjustment	1,381	1,595
Effect of changes in cash flow assumptions	(4)	8
Effect of actual variances from expected experience	(9)	2
Adjusted balance	1,368	1,605
Assessments accrual	(3)	(2)
Interest accrual	15	16
Excess benefits paid	(29)	(31)
Effect of foreign currency translation and other, net	(158)	(324)
Balance, end of period, before AOCI adjustment	1,193	1,264
Add: AOCI adjustment	0	0
Balance, end of period	$ 1,193	$ 1,264
Weighted-average duration of the liability	16 years	17 years
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]
Balance, beginning of period	$ 455	$ 655
Less: AOCI adjustment	(33)	56
Balance, beginning of period, before AOCI adjustment	488	599
Effect of changes in cash flow assumptions	(2)	(1)
Effect of actual variances from expected experience	(32)	(56)
Adjusted balance	454	542
Assessments accrual	0	(1)
Interest accrual	5	6
Excess benefits paid	0	0
Effect of foreign currency translation and other, net	(55)	(117)
Balance, end of period, before AOCI adjustment	404	430
Add: AOCI adjustment	(18)	(28)
Balance, end of period	$ 386	$ 402
Weighted-average duration of the liability	43 years	43 years
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]
Balance, beginning of period	$ 2,156	$ 2,117
Less: AOCI adjustment	(63)	67
Balance, beginning of period, before AOCI adjustment	2,219	2,050
Effect of changes in cash flow assumptions	38	35
Effect of actual variances from expected experience	(10)	27
Adjusted balance	2,247	2,112
Assessments accrual	80	77
Interest accrual	92	86
Excess benefits paid	(81)	(90)
Balance, end of period, before AOCI adjustment	2,338	2,185
Add: AOCI adjustment	(65)	(66)
Balance, end of period	2,273	2,119
Less: Reinsurance recoverables	766	741
Balance, end of period, net of reinsurance	$ 1,507	$ 1,378
Weighted-average duration of the liability	16 years	16 years
Weighted-average interest accretion rate	5.50%	5.60%