Future Policy Benefits - FPB - Additional Insurance Liabilities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Variable Life | Asia
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	$ 1,258	$ 1,381
Less: AOCI adjustment	0	0
Balance, beginning of period, before AOCI adjustment	1,258	1,381
Effect of actual variances from expected experience	(14)	(8)
Adjusted balance	1,244	1,373
Assessments accrual	(2)	(2)
Interest accrual	9	10
Excess benefits paid	(23)	(19)
Effect of foreign currency translation and other, net	(154)	(119)
Balance, end of period, before AOCI adjustment	1,074	1,243
Add: AOCI adjustment	0	0
Balance, end of period	$ 1,074	$ 1,243
Weighted-average duration of the liability	16 years	17 years
Weighted-average interest accretion rate	1.50%	1.50%
Universal and Variable Universal Life | Asia
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	$ 424	$ 455
Less: AOCI adjustment	(14)	(33)
Balance, beginning of period, before AOCI adjustment	438	488
Effect of actual variances from expected experience	(32)	(22)
Adjusted balance	406	466
Assessments accrual	0	0
Interest accrual	3	3
Excess benefits paid	0	0
Effect of foreign currency translation and other, net	(53)	(41)
Balance, end of period, before AOCI adjustment	356	428
Add: AOCI adjustment	(2)	(18)
Balance, end of period	$ 354	$ 410
Weighted-average duration of the liability	43 years	43 years
Weighted-average interest accretion rate	1.50%	1.50%
Universal and Variable Universal Life | MetLife Holdings
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	$ 2,362	$ 2,156
Less: AOCI adjustment	(14)	(63)
Balance, beginning of period, before AOCI adjustment	2,376	2,219
Effect of actual variances from expected experience	28	(6)
Adjusted balance	2,404	2,213
Assessments accrual	51	55
Interest accrual	65	61
Excess benefits paid	(70)	(63)
Balance, end of period, before AOCI adjustment	2,450	2,266
Add: AOCI adjustment	(16)	2
Balance, end of period	2,434	2,268
Less: Reinsurance recoverables	2,117	744
Balance, end of period, net of reinsurance	$ 317	$ 1,524
Weighted-average duration of the liability	15 years	16 years
Weighted-average interest accretion rate	5.50%	5.60%