Policyholder Account Balances - LDTI Rollforward (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	$ 219,269
Balance, end of period	224,609
Group Life - Term | Group Benefits
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	7,692	$ 8,028
Deposits	2,857	2,529
Policy charges	(493)	(475)
Surrenders and withdrawals	(2,512)	(2,432)
Benefit payments	(9)	(9)
Net transfers from (to) separate accounts	(3)	1
Interest credited	144	143
Balance, end of period	$ 7,676	$ 7,785
Weighted-average annual crediting rate	2.50%	2.40%
Cash surrender value	$ 7,614	$ 7,721
Group Life - Term | In the event of death | Group Benefits
Policyholder Account Balance [Roll Forward]
Net amount at risk	265,266	250,611
Capital Markets Investment Products and Stable Value GICs | RIS
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	64,140	63,723
Deposits	56,170	54,674
Surrenders and withdrawals	(57,068)	(56,873)
Interest credited	1,811	1,524
Effect of foreign currency translation and other, net	277	369
Balance, end of period	$ 65,330	$ 63,417
Weighted-average annual crediting rate	3.80%	3.20%
Cash surrender value	$ 1,953	$ 2,110
Annuities and Risk Solutions | RIS
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	17,711	15,549
Deposits	2,367	2,007
Policy charges	(122)	(133)
Surrenders and withdrawals	(239)	(134)
Benefit payments	(731)	(615)
Net transfers from (to) separate accounts	20	54
Interest credited	556	469
Other	10	(133)
Balance, end of period	$ 19,572	$ 17,064
Weighted-average annual crediting rate	4.00%	3.90%
Cash surrender value	$ 8,476	$ 7,693
Annuities and Risk Solutions | In the event of death | RIS
Policyholder Account Balance [Roll Forward]
Net amount at risk	44,437	42,043
Universal and Variable Universal Life | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	49,739	46,417
Deposits	4,694	5,439
Policy charges	(812)	(888)
Surrenders and withdrawals	(2,483)	(2,018)
Benefit payments	(345)	(393)
Interest credited	1,153	979
Effect of foreign currency translation and other, net	(190)	(1,906)
Balance, end of period	$ 51,756	$ 47,630
Weighted-average annual crediting rate	3.10%	2.80%
Cash surrender value	$ 46,366	$ 40,663
Universal and Variable Universal Life | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	89,793	91,861
Fixed Annuity | Asia
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	36,863	32,454
Deposits	5,002	6,230
Policy charges	(2)	(2)
Surrenders and withdrawals	(2,248)	(1,665)
Benefit payments	(1,718)	(1,614)
Interest credited	784	629
Effect of foreign currency translation and other, net	61	(552)
Balance, end of period	$ 38,742	$ 35,480
Weighted-average annual crediting rate	2.80%	2.50%
Cash surrender value	$ 35,005	$ 30,289
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	11,537	13,286
Deposits	121	115
Policy charges	(10)	(12)
Surrenders and withdrawals	(1,292)	(1,425)
Benefit payments	(298)	(320)
Net transfers from (to) separate accounts	105	48
Interest credited	265	299
Other	9	15
Balance, end of period	$ 10,437	$ 12,006
Weighted-average annual crediting rate	3.30%	3.20%
Cash surrender value	$ 9,866	$ 11,263
Fixed Annuity | In the event of death | Asia
Policyholder Account Balance [Roll Forward]
Net amount at risk	8	0
Fixed Annuity | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	2,238	3,970
Fixed Annuity | At annuitization or exercise of other living benefits | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	657	923
Variable Annuity | EMEA
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	2,720	2,802
Deposits	2	3
Policy charges	(44)	(48)
Surrenders and withdrawals	(214)	(206)
Benefit payments	(95)	(95)
Interest credited	117	69
Effect of foreign currency translation and other, net	131	46
Balance, end of period	$ 2,617	$ 2,571
Weighted-average annual crediting rate	6.00%	3.50%
Cash surrender value	$ 2,617	$ 2,571
Variable Annuity | In the event of death | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	426	577
Variable Annuity | At annuitization or exercise of other living benefits | EMEA
Policyholder Account Balance [Roll Forward]
Net amount at risk	550	725
Life and Other | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Balance, beginning of period	11,641	12,402
Deposits	549	617
Policy charges	(519)	(529)
Surrenders and withdrawals	(744)	(892)
Benefit payments	(114)	(120)
Net transfers from (to) separate accounts	26	29
Interest credited	318	336
Other	127	1
Balance, end of period	$ 11,284	$ 11,844
Weighted-average annual crediting rate	3.80%	3.80%
Cash surrender value	$ 10,722	$ 11,360
Net amount at risk percentage after taking reinsurance into consideration	99.00%		99.00%
Life and Other | In the event of death | MetLife Holdings
Policyholder Account Balance [Roll Forward]
Net amount at risk	$ 64,816	$ 68,972