Policyholder Account Balances - LDTI Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	$ 219,269
Balance, end of period	$ 219,168
Net amount at risk percentage after taking reinsurance into consideration	99.00%		99.00%
Group Life - Term | Group Benefits
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	$ 7,692	$ 8,028
Deposits	1,083	851
Policy charges	(163)	(160)
Surrenders and withdrawals	(906)	(799)
Benefit payments	(4)	(1)
Net transfers from (to) separate accounts	(3)	1
Interest credited	48	45
Balance, end of period	$ 7,747	$ 7,965
Weighted-average annual crediting rate	2.50%	2.30%
Cash surrender value	$ 7,687	$ 7,904
Group Life - Term | In the event of death | Group Benefits
Policyholder Account Balance [Roll Forward]
Net amount at risk	260,502	249,463
Capital Markets Investment Products and Stable Value GICs | RIS
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	64,140	63,723
Deposits	18,073	21,234
Surrenders and withdrawals	(18,070)	(22,590)
Interest credited	573	460
Effect of foreign currency translation and other, net	(447)	457
Balance, end of period	$ 64,269	$ 63,284
Weighted-average annual crediting rate	3.60%	2.90%
Cash surrender value	$ 1,992	$ 2,074
Annuities and Risk Solutions | RIS
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	17,711	15,549
Deposits	700	629
Policy charges	(15)	(47)
Surrenders and withdrawals	(58)	(39)
Benefit payments	(242)	(191)
Net transfers from (to) separate accounts	19	55
Interest credited	177	151
Other	(26)	21
Balance, end of period	$ 18,266	$ 16,128
Weighted-average annual crediting rate	3.90%	3.80%
Cash surrender value	$ 8,043	$ 7,592
Annuities and Risk Solutions | In the event of death | RIS
Policyholder Account Balance [Roll Forward]
Net amount at risk	42,677	41,924
Universal and Variable Universal Life | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	49,739	46,417
Deposits	1,682	1,070
Policy charges	(282)	(242)
Surrenders and withdrawals	(826)	(517)
Benefit payments	(124)	(149)
Interest credited	382	344
Effect of foreign currency translation and other, net	(1,087)	(153)
Balance, end of period	$ 49,484	$ 46,770
Weighted-average annual crediting rate	3.10%	3.00%
Cash surrender value	$ 42,842	$ 40,028
Universal and Variable Universal Life | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	90,786	94,001
Fixed Annuity | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	36,863	32,454
Deposits	1,665	2,733
Policy charges	0	(1)
Surrenders and withdrawals	(740)	(445)
Benefit payments	(649)	(545)
Interest credited	248	191
Effect of foreign currency translation and other, net	(418)	(115)
Balance, end of period	$ 36,969	$ 34,272
Weighted-average annual crediting rate	2.70%	2.30%
Cash surrender value	$ 32,072	$ 29,162
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	11,537	13,286
Deposits	38	41
Policy charges	(3)	(4)
Surrenders and withdrawals	(457)	(531)
Benefit payments	(108)	(119)
Net transfers from (to) separate accounts	27	35
Interest credited	91	100
Other	4	10
Balance, end of period	$ 11,129	$ 12,818
Weighted-average annual crediting rate	3.30%	3.10%
Cash surrender value	$ 10,507	$ 11,981
Fixed Annuity | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	3	0
Fixed Annuity | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	2,486	3,600
Fixed Annuity | At annuitization or exercise of other living benefits | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	614	831
Variable Annuity | EMEA
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	2,720	2,802
Deposits	1	1
Policy charges	(15)	(16)
Surrenders and withdrawals	(73)	(65)
Benefit payments	(31)	(31)
Interest credited	54	77
Effect of foreign currency translation and other, net	(25)	77
Balance, end of period	$ 2,631	$ 2,845
Weighted-average annual crediting rate	8.40%	11.60%
Cash surrender value	$ 2,631	$ 2,845
Variable Annuity | In the event of death | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	422	565
Variable Annuity | At annuitization or exercise of other living benefits | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	541	713
Life and Other | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	11,641	12,402
Deposits	206	226
Policy charges	(174)	(179)
Surrenders and withdrawals	(265)	(287)
Benefit payments	(39)	(47)
Net transfers from (to) separate accounts	11	6
Interest credited	106	113
Other	0	0
Balance, end of period	$ 11,486	$ 12,234
Weighted-average annual crediting rate	3.70%	3.70%
Cash surrender value	$ 11,038	$ 11,731
Life and Other | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	$ 66,684	$ 70,483