Policyholder Account Balances - LDTI Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	$ 210,597
Interest credited	7,970	$ 3,771	$ 5,628
Balance, end of period	$ 219,269	$ 210,597
Net amount at risk percentage after taking reinsurance into consideration	99.00%	65.00%	66.00%
Group Life - Term | Group Benefits
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	$ 8,028	$ 7,893	$ 7,586
Deposits	3,311	3,361	3,450
Policy charges	(635)	(612)	(589)
Surrenders and withdrawals	(3,192)	(2,744)	(2,670)
Benefit payments	(12)	(10)	(9)
Net transfers from (to) separate accounts	0	(2)	(1)
Interest credited	192	142	126
Balance, end of period	$ 7,692	$ 8,028	$ 7,893
Weighted-average annual crediting rate	2.50%	1.80%	1.60%
Cash surrender value at period end	$ 7,630	$ 7,974	$ 7,840
Group Life - Term | In the event of death | Group Benefits
Policyholder Account Balance [Roll Forward]
Net amount at risk	250,033	244,638	238,062
Capital Markets Investment Products and Stable Value GICs | Retirement and Income Solutions
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	63,723	62,521	62,908
Deposits	69,229	81,050	76,672
Surrenders and withdrawals	(71,938)	(80,382)	(77,524)
Interest credited	2,091	1,276	914
Effect of foreign currency translation and other, net	1,035	(742)	(449)
Balance, end of period	$ 64,140	$ 63,723	$ 62,521
Weighted-average annual crediting rate	3.30%	2.00%	1.50%
Cash surrender value at period end	$ 2,126	$ 2,071	$ 1,882
Annuities and Risk Solutions | Retirement and Income Solutions
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	15,549	14,431	13,643
Deposits	2,734	1,843	1,615
Policy charges	(178)	(153)	(126)
Surrenders and withdrawals	(210)	(120)	(442)
Benefit payments	(812)	(739)	(704)
Net transfers from (to) separate accounts	53	(26)	11
Interest credited	637	543	517
Other	(62)	(230)	(83)
Balance, end of period	$ 17,711	$ 15,549	$ 14,431
Weighted-average annual crediting rate	3.90%	3.70%	3.80%
Cash surrender value at period end	$ 7,912	$ 7,331	$ 6,559
Annuities and Risk Solutions | In the event of death | Retirement and Income Solutions
Policyholder Account Balance [Roll Forward]
Net amount at risk	40,397	40,607	38,066
Universal and Variable Universal Life | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	46,417	46,590	43,868
Deposits	7,595	5,673	6,487
Policy charges	(1,210)	(1,103)	(1,178)
Surrenders and withdrawals	(2,959)	(2,993)	(1,265)
Benefit payments	(508)	(502)	(514)
Interest credited	1,408	1,066	1,199
Effect of foreign currency translation and other, net	(1,004)	(2,314)	(2,007)
Balance, end of period	$ 49,739	$ 46,417	$ 46,590
Weighted-average annual crediting rate	3.00%	2.30%	2.70%
Cash surrender value at period end	$ 42,577	$ 39,737	$ 43,329
Universal and Variable Universal Life | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	93,172	95,412	104,551
Fixed Annuity | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	32,454	30,976	31,422
Deposits	8,115	7,813	3,681
Policy charges	(2)	(2)	(3)
Surrenders and withdrawals	(2,344)	(4,024)	(1,260)
Benefit payments	(2,156)	(2,014)	(2,500)
Interest credited	866	623	617
Effect of foreign currency translation and other, net	(70)	(918)	(981)
Balance, end of period	$ 36,863	$ 32,454	$ 30,976
Weighted-average annual crediting rate	2.50%	2.00%	2.00%
Cash surrender value at period end	$ 31,936	$ 27,902	$ 29,835
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	13,286	14,398	15,234
Deposits	176	233	284
Policy charges	(15)	(16)	(16)
Surrenders and withdrawals	(1,981)	(1,494)	(1,380)
Benefit payments	(420)	(415)	(413)
Net transfers from (to) separate accounts	72	198	237
Interest credited	396	406	425
Other	23	(24)	27
Balance, end of period	$ 11,537	$ 13,286	$ 14,398
Weighted-average annual crediting rate	3.30%	3.00%	3.00%
Cash surrender value at period end	$ 10,904	$ 12,373	$ 13,256
Fixed Annuity | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	73	1	64
Fixed Annuity | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	2,821	4,354	1,119
Fixed Annuity | At annuitization or exercise of other living benefits | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	688	960	581
Variable Annuity | EMEA
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	2,802	4,215	4,779
Deposits	4	5	8
Policy charges	(63)	(73)	(95)
Surrenders and withdrawals	(285)	(313)	(483)
Benefit payments	(125)	(137)	(157)
Interest credited	228	(465)	208
Effect of foreign currency translation and other, net	159	(430)	(45)
Balance, end of period	$ 2,720	$ 2,802	$ 4,215
Weighted-average annual crediting rate	8.60%	(12.40%)	4.70%
Cash surrender value at period end	$ 2,720	$ 2,802	$ 4,215
Variable Annuity | In the event of death | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	456	557	182
Variable Annuity | At annuitization or exercise of other living benefits | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	585	699	257
Life and Other | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	12,402	12,699	12,856
Deposits	783	895	1,172
Policy charges	(702)	(718)	(731)
Surrenders and withdrawals	(1,171)	(785)	(887)
Benefit payments	(152)	(183)	(213)
Net transfers from (to) separate accounts	35	29	32
Interest credited	445	460	470
Other	1	5	0
Balance, end of period	$ 11,641	$ 12,402	$ 12,699
Weighted-average annual crediting rate	3.80%	3.70%	3.80%
Cash surrender value at period end	$ 11,177	$ 11,882	$ 12,170
Life and Other | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	$ 67,786	$ 71,548	$ 73,840