Policyholder Account Balances - LDTI Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	$ 219,269
Interest credited	8,484	$ 7,970	$ 3,771
Balance, end of period	221,445	219,269
Group Life - Term | Group Benefits
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	7,692	8,028	7,893
Deposits	3,720	3,311	3,361
Policy charges	(658)	(635)	(612)
Surrenders and withdrawals	(3,296)	(3,192)	(2,744)
Benefit payments	(13)	(12)	(10)
Net transfers from (to) separate accounts	(3)	0	(2)
Interest credited	190	192	142
Balance, end of period	$ 7,632	$ 7,692	$ 8,028
Weighted-average annual crediting rate	2.50%	2.50%	1.80%
Cash surrender value at period end	$ 7,569	$ 7,630	$ 7,974
Group Life - Term | In the event of death | Group Benefits
Policyholder Account Balance [Roll Forward]
Net amount at risk	263,198	250,033	244,638
Capital Markets Investment Products and Stable Value GICs | RIS
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	64,140	63,723	62,521
Deposits	73,103	69,229	81,050
Surrenders and withdrawals	(74,974)	(71,938)	(80,382)
Interest credited	2,424	2,091	1,276
Effect of foreign currency translation and other, net	(978)	1,035	(742)
Balance, end of period	$ 63,715	$ 64,140	$ 63,723
Weighted-average annual crediting rate	3.90%	3.30%	2.00%
Cash surrender value at period end	$ 1,936	$ 2,126	$ 2,071
Annuities and Risk Solutions | RIS
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	17,711	15,549	14,431
Deposits	3,747	2,734	1,843
Policy charges	(138)	(178)	(153)
Surrenders and withdrawals	(527)	(210)	(120)
Benefit payments	(961)	(812)	(739)
Net transfers from (to) separate accounts	3	53	(26)
Interest credited	761	637	543
Other	103	(62)	(230)
Balance, end of period	$ 20,699	$ 17,711	$ 15,549
Weighted-average annual crediting rate	4.00%	3.90%	3.70%
Cash surrender value at period end	$ 9,396	$ 7,912	$ 7,331
Annuities and Risk Solutions | In the event of death | RIS
Policyholder Account Balance [Roll Forward]
Net amount at risk	43,786	40,397	40,607
Universal and Variable Universal Life | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	49,739	46,417	46,590
Deposits	5,885	7,595	5,673
Policy charges	(1,046)	(1,210)	(1,103)
Surrenders and withdrawals	(3,171)	(2,959)	(2,993)
Benefit payments	(451)	(508)	(502)
Interest credited	1,517	1,408	1,066
Effect of foreign currency translation and other, net	(1,672)	(1,004)	(2,314)
Balance, end of period	$ 50,801	$ 49,739	$ 46,417
Weighted-average annual crediting rate	3.10%	3.00%	2.30%
Cash surrender value at period end	$ 44,685	$ 42,577	$ 39,737
Universal and Variable Universal Life | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	86,683	93,172	95,412
Fixed Annuity | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	36,863	32,454	30,976
Deposits	6,221	8,115	7,813
Policy charges	(2)	(2)	(2)
Surrenders and withdrawals	(2,760)	(2,344)	(4,024)
Benefit payments	(2,208)	(2,156)	(2,014)
Interest credited	1,070	866	623
Effect of foreign currency translation and other, net	(763)	(70)	(918)
Balance, end of period	$ 38,421	$ 36,863	$ 32,454
Weighted-average annual crediting rate	2.90%	2.50%	2.00%
Cash surrender value at period end	$ 34,105	$ 31,936	$ 27,902
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	11,537	13,286	14,398
Deposits	167	176	233
Policy charges	(13)	(15)	(16)
Surrenders and withdrawals	(1,688)	(1,981)	(1,494)
Benefit payments	(390)	(420)	(415)
Net transfers from (to) separate accounts	146	72	198
Interest credited	349	396	406
Other	34	23	(24)
Balance, end of period	$ 10,142	$ 11,537	$ 13,286
Weighted-average annual crediting rate	3.30%	3.30%	3.00%
Cash surrender value at period end	$ 9,555	$ 10,904	$ 12,373
Fixed Annuity | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	1	73	1
Fixed Annuity | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	2,540	2,821	4,354
Fixed Annuity | At annuitization or exercise of other living benefits | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	750	688	960
Variable Annuity | EMEA
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	2,720	2,802	4,215
Deposits	3	4	5
Policy charges	(57)	(63)	(73)
Surrenders and withdrawals	(277)	(285)	(313)
Benefit payments	(126)	(125)	(137)
Interest credited	115	228	(465)
Effect of foreign currency translation and other, net	(41)	159	(430)
Balance, end of period	$ 2,337	$ 2,720	$ 2,802
Weighted-average annual crediting rate	4.70%	8.60%	(12.40%)
Cash surrender value at period end	$ 2,337	$ 2,720	$ 2,802
Variable Annuity | In the event of death | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	414	456	557
Variable Annuity | At annuitization or exercise of other living benefits | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	532	585	699
Life and Other | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	11,641	12,402	12,699
Deposits	784	783	895
Policy charges	(690)	(702)	(718)
Surrenders and withdrawals	(1,053)	(1,171)	(785)
Benefit payments	(151)	(152)	(183)
Net transfers from (to) separate accounts	51	35	29
Interest credited	421	445	460
Other	129	1	5
Balance, end of period	$ 11,132	$ 11,641	$ 12,402
Weighted-average annual crediting rate	3.80%	3.80%	3.70%
Cash surrender value at period end	$ 10,576	$ 11,177	$ 11,882
Net amount at risk percentage after taking reinsurance into consideration	99.00%	99.00%	65.00%
Life and Other | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	$ 64,031	$ 67,786	$ 71,548