Future Policy Benefits - FPB - Additional Insurance Liabilities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Jun. 30, 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	(6)	(14)
Adjusted balance	1,102	1,244
Assessments accrual	(2)	(2)
Interest accrual	9	9
Excess benefits paid	(19)	(23)
Effect of foreign currency translation and other, net	98	(154)
Balance, end of period, before AOCI adjustment	1,188	1,074
Add: AOCI adjustment	0	0
Balance, end of period	$ 1,188	$ 1,074
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	(4)	(32)
Adjusted balance	341	406
Assessments accrual	0	0
Interest accrual	3	3
Excess benefits paid	0	0
Effect of foreign currency translation and other, net	31	(53)
Balance, end of period, before AOCI adjustment	375	356
Add: AOCI adjustment	11	(2)
Balance, end of period	$ 386	$ 354
Weighted-average duration of the liability	42 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	$ 2,496	$ 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	18	28
Adjusted balance	2,531	2,404
Assessments accrual	54	51
Interest accrual	68	65
Excess benefits paid	(71)	(70)
Balance, end of period, before AOCI adjustment	2,582	2,450
Add: AOCI adjustment	(15)	(16)
Balance, end of period	2,567	2,434
Less: Reinsurance recoverables	2,230	2,117
Balance, end of period, net of reinsurance	$ 337	$ 317
Weighted-average duration of the liability	15 years	15 years
Weighted-average interest accretion rate	5.50%	5.50%