Future Policy Benefits - FPB - Additional Insurance Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Variable Life | Asia
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	$ 1,108	$ 1,258
Less: AOCI adjustment	0	0
Balance, beginning of period, before AOCI adjustment	1,108	1,258
Effect of actual variances from expected experience	(2)	(13)
Adjusted balance	1,106	1,245
Assessments accrual	(1)	(1)
Interest accrual	4	4
Excess benefits paid	(9)	(9)
Effect of foreign currency translation and other, net	57	(86)
Balance, end of period, before AOCI adjustment	1,157	1,153
Add: AOCI adjustment	0	0
Balance, end of period	$ 1,157	$ 1,153
Weighted-average duration of the liability	16 years	16 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	$ 355	$ 424
Less: AOCI adjustment	10	(14)
Balance, beginning of period, before AOCI adjustment	345	438
Effect of actual variances from expected experience	(2)	(17)
Adjusted balance	343	421
Assessments accrual	0	0
Interest accrual	1	1
Excess benefits paid	0	0
Effect of foreign currency translation and other, net	18	(30)
Balance, end of period, before AOCI adjustment	362	392
Add: AOCI adjustment	10	(7)
Balance, end of period	$ 372	$ 385
Weighted-average duration of the liability	42 years	43 years
Weighted-average interest accretion rate	1.50%	1.40%
Universal and Variable Universal Life | MetLife Holdings
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	$ 2,496	$ 2,362
Less: AOCI adjustment	(17)	(14)
Balance, beginning of period, before AOCI adjustment	2,513	2,376
Effect of actual variances from expected experience	11	14
Adjusted balance	2,524	2,390
Assessments accrual	27	26
Interest accrual	34	32
Excess benefits paid	(42)	(37)
Balance, end of period, before AOCI adjustment	2,543	2,411
Add: AOCI adjustment	(15)	(15)
Balance, end of period	2,528	2,396
Less: Reinsurance recoverables	2,197	2,086
Balance, end of period, net of reinsurance	$ 331	$ 310
Weighted-average duration of the liability	15 years	15 years
Weighted-average interest accretion rate	5.50%	5.50%