Future Policy Benefits - Disaggregate Rollforwards (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Net liability for FPBs	$ 191,013		$ 196,406
Fixed & Immediate Annuities | RIS
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period, at current discount rate at balance sheet date	0	$ 0
Balance, beginning of period, at original discount rate	0	0
Effect of actual variances from expected experience (1)	(26)	(16)
Adjusted balance	(26)	(16)
Issuances	342	236
Net premiums collected	(316)	(220)
Ending balance at original discount rate	0	0
Balance, end of period, at current discount rate at balance sheet date	0	0
Balance, beginning of period, at current discount rate at balance sheet date	64,515	58,695
Balance, beginning of period, at original discount rate	64,737	61,426
Effect of actual variances from expected experience (1)	(36)	(116)
Adjusted balance	64,701	61,310
Issuances	341	234
Interest accrual	759	703
Benefit payments	(1,492)	(1,372)
Ending balance at original discount rate	64,309	60,875
Effect of changes in discount rate assumptions	(1,649)	(1,202)
Balance, end of period, at current discount rate at balance sheet date	62,660	59,673
Cumulative amount of fair value hedging adjustments	(298)	(78)
Net liability for FPBs	62,362	59,595	64,324
Less: Reinsurance recoverables	256	0
Net liability for FPBs, net of reinsurance	62,106	59,595
Undiscounted - Expected future benefit payments	118,190	113,912
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 62,660	$ 59,673
Weighted-average duration of the liability	9 years	9 years
Weighted-average interest accretion (original locked-in) rate	4.80%	4.70%
Weighted-average current discount rate at balance sheet date	5.40%	5.10%
Deferred Profit Liability Offset to Actual Versus Expected	$ 10	$ 71
Whole and Term Life & Endowments | Asia
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period, at current discount rate at balance sheet date	4,561	4,682
Balance, beginning of period, at original discount rate	4,793	4,943
Effect of actual variances from expected experience (1)	(15)	(22)
Adjusted balance	4,778	4,921
Issuances	153	141
Interest accrual	17	13
Net premiums collected	(157)	(153)
Effect of foreign currency translation	(290)	(44)
Ending balance at original discount rate	4,501	4,878
Effect of changes in discount rate assumptions	(260)	(201)
Effect of foreign currency translation on the effect of changes in discount rate assumptions	16	3
Balance, end of period, at current discount rate at balance sheet date	4,257	4,680
Balance, beginning of period, at current discount rate at balance sheet date	17,435	17,463
Balance, beginning of period, at original discount rate	17,198	18,209
Effect of actual variances from expected experience (1)	(7)	(4)
Adjusted balance	17,191	18,205
Issuances	153	141
Interest accrual	93	93
Benefit payments	(263)	(340)
Effect of foreign currency translation	(1,042)	(220)
Ending balance at original discount rate	16,132	17,879
Effect of changes in discount rate assumptions	(36)	329
Effect of foreign currency translation on the effect of changes in discount rate assumptions	22	(32)
Balance, end of period, at current discount rate at balance sheet date	16,118	18,176
Cumulative amount of fair value hedging adjustments	0	2
Net liability for FPBs	11,861	13,498	12,874
Less: Reinsurance recoverables	(1)	(1)
Net liability for FPBs, net of reinsurance	11,862	13,499
Undiscounted - Expected future gross premiums	8,799	9,309
Undiscounted - Expected future benefit payments	26,638	28,009
Discounted - Expected future gross premiums	7,549	8,146
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 16,118	$ 18,176
Weighted-average duration of the liability	17 years	17 years
Weighted-average interest accretion (original locked-in) rate	2.60%	2.50%
Weighted-average current discount rate at balance sheet date	2.70%	2.40%
Accident & health insurance | Asia
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period, at current discount rate at balance sheet date	$ 19,835	$ 21,181
Balance, beginning of period, at original discount rate	21,232	22,594
Effect of actual variances from expected experience (1)	(123)	(55)
Adjusted balance	21,109	22,539
Issuances	252	257
Interest accrual	56	61
Net premiums collected	(483)	(546)
Effect of foreign currency translation	(1,399)	(225)
Ending balance at original discount rate	19,535	22,086
Effect of changes in discount rate assumptions	(1,549)	(1,051)
Effect of foreign currency translation on the effect of changes in discount rate assumptions	99	16
Balance, end of period, at current discount rate at balance sheet date	18,085	21,051
Balance, beginning of period, at current discount rate at balance sheet date	30,480	30,879
Balance, beginning of period, at original discount rate	36,010	37,189
Effect of actual variances from expected experience (1)	(130)	(60)
Adjusted balance	35,880	37,129
Issuances	252	256
Interest accrual	118	125
Benefit payments	(303)	(323)
Effect of foreign currency translation	(2,334)	(400)
Ending balance at original discount rate	33,613	36,787
Effect of changes in discount rate assumptions	(6,132)	(4,726)
Effect of foreign currency translation on the effect of changes in discount rate assumptions	395	54
Balance, end of period, at current discount rate at balance sheet date	27,876	32,115
Cumulative amount of fair value hedging adjustments	68	113
Net liability for FPBs	9,859	11,177	10,712
Less: Reinsurance recoverables	166	155
Net liability for FPBs, net of reinsurance	9,693	11,022
Undiscounted - Expected future gross premiums	38,523	42,544
Undiscounted - Expected future benefit payments	43,983	47,574
Discounted - Expected future gross premiums	31,377	36,047
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 27,876	$ 32,115
Weighted-average duration of the liability	24 years	26 years
Weighted-average interest accretion (original locked-in) rate	1.70%	1.80%
Weighted-average current discount rate at balance sheet date	2.70%	2.30%
Fixed Annuity | Latin America
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period, at current discount rate at balance sheet date	$ 0	$ 0
Balance, beginning of period, at original discount rate	0	0
Effect of actual variances from expected experience (1)	0	0
Adjusted balance	0	0
Issuances	260	294
Interest accrual	1	2
Net premiums collected	(261)	(296)
Ending balance at original discount rate	0	0
Balance, end of period, at current discount rate at balance sheet date	0	0
Balance, beginning of period, at current discount rate at balance sheet date	9,637	9,265
Balance, beginning of period, at original discount rate	9,249	8,240
Effect of actual variances from expected experience (1)	(5)	(8)
Adjusted balance	9,244	8,232
Issuances	265	325
Interest accrual	82	85
Benefit payments	(165)	(162)
Inflation adjustment	73	116
Effect of foreign currency translation	(976)	649
Ending balance at original discount rate	8,523	9,245
Effect of changes in discount rate assumptions	285	976
Effect of foreign currency translation on the effect of changes in discount rate assumptions	(37)	77
Balance, end of period, at current discount rate at balance sheet date	8,771	10,298
Net liability for FPBs	8,771	10,298	9,637
Undiscounted - Expected future benefit payments	12,863	14,095
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 8,771	$ 10,298
Weighted-average duration of the liability	10 years	11 years
Weighted-average interest accretion (original locked-in) rate	3.70%	3.90%
Weighted-average current discount rate at balance sheet date	3.40%	2.70%
Deferred Profit Liability Offset to Actual Versus Expected		$ 3
Long-term Care | MetLife Holdings
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period, at current discount rate at balance sheet date	$ 5,687	5,775
Balance, beginning of period, at original discount rate	5,566	5,807
Effect of actual variances from expected experience (1)	(4)	26
Adjusted balance	5,562	5,833
Interest accrual	71	75
Net premiums collected	(143)	(146)
Ending balance at original discount rate	5,490	5,762
Effect of changes in discount rate assumptions	0	104
Balance, end of period, at current discount rate at balance sheet date	5,490	5,866
Balance, beginning of period, at current discount rate at balance sheet date	20,927	19,619
Balance, beginning of period, at original discount rate	20,494	20,165
Effect of actual variances from expected experience (1)	(1)	28
Adjusted balance	20,493	20,193
Interest accrual	269	266
Benefit payments	(212)	(191)
Ending balance at original discount rate	20,550	20,268
Effect of changes in discount rate assumptions	(215)	215
Balance, end of period, at current discount rate at balance sheet date	20,335	20,483
Net liability for FPBs	14,845	14,617	$ 15,240
Undiscounted - Expected future gross premiums	10,430	11,053
Undiscounted - Expected future benefit payments	44,808	45,741
Discounted - Expected future gross premiums	6,895	7,295
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 20,335	$ 20,483
Weighted-average duration of the liability	14 years	15 years
Weighted-average interest accretion (original locked-in) rate	5.40%	5.40%
Weighted-average current discount rate at balance sheet date	5.50%	5.30%