Future Policy Benefits - Disaggregate Rollforwards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Net liability for future policy benefits	$ 196,406	$ 187,222		$ 224,358
Fixed & Immediate Annuities | Retirement and Income Solutions
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	$ 0
Balance, beginning of period, at original discount rate	0	0	0
Effect of changes in cash flow assumptions	0	0	0
Effect of actual variances from expected experience	(106)	(94)	(60)
Adjusted balance	(106)	(94)	(60)
Issuances	6,572	12,672	3,995
Net premiums collected	(6,466)	(12,578)	(3,935)
Ending balance at original discount rate	0	0	0
Balance, end of period, at current discount rate at balance sheet date	0	0	0
Balance, beginning of period, at current discount rate at balance sheet date	58,695	62,954	64,896
Balance, beginning of period, at original discount rate	61,426	50,890	49,061
Effect of changes in cash flow assumptions	(284)	(115)	(130)
Effect of actual variances from expected experience	(270)	(175)	(270)
Adjusted balance	60,872	50,600	48,661
Issuances	6,588	12,770	4,060
Interest accrual	2,897	2,519	2,336
Benefit payments	(5,620)	(4,463)	(4,167)
Ending balance at original discount rate	64,737	61,426	50,890
Effect of changes in discount rate assumptions	(222)	(2,731)	12,064
Balance, end of period, at current discount rate at balance sheet date	64,515	58,695	62,954
Cumulative amount of fair value hedging adjustments	(191)	(200)	727
Net liability for future policy benefits	64,324	58,495	63,681
Less: Reinsurance recoverables (Amount due to reinsurer)	269	0	312
Net liability for future policy benefits, net of reinsurance	64,055	58,495	63,369
Undiscounted - Expected future benefit payments	130,878	113,932	96,623
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 64,515	$ 58,695	$ 62,954
Weighted-average duration of the liability	9 years	9 years	12 years
Weighted -average interest accretion (original locked-in) rate	4.70%	4.60%	4.80%
Weighted-average current discount rate at balance sheet date	5.10%	5.50%	2.90%
Deferred Profit Liability Offset to Cash Flow Assumption Update	$ 211	$ 128	$ 112
Deferred Profit Liability Offset to Actual Versus Expected	118	46	197
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	4,682	5,986	7,396
Balance, beginning of period, at original discount rate	4,943	5,881	7,243
Effect of changes in cash flow assumptions	11	69	(60)
Effect of actual variances from expected experience	(62)	28	(80)
Adjusted balance	4,892	5,978	7,103
Issuances	730	231	208
Interest accrual	59	44	51
Net premiums collected	(611)	(615)	(777)
Effect of foreign currency translation	(277)	(695)	(704)
Ending balance at original discount rate	4,793	4,943	5,881
Effect of changes in discount rate assumptions	(242)	(247)	117
Effect of foreign currency translation on the effect of changes in discount rate assumptions	10	(14)	(12)
Balance, end of period, at current discount rate at balance sheet date	4,561	4,682	5,986
Balance, beginning of period, at current discount rate at balance sheet date	17,463	24,453	29,581
Balance, beginning of period, at original discount rate	18,209	21,276	25,063
Effect of changes in cash flow assumptions	58	96	(108)
Effect of actual variances from expected experience	(30)	54	(70)
Adjusted balance	18,237	21,426	24,885
Issuances	729	231	208
Interest accrual	370	364	422
Benefit payments	(1,174)	(1,406)	(1,794)
Effect of foreign currency translation	(964)	(2,406)	(2,445)
Ending balance at original discount rate	17,198	18,209	21,276
Effect of changes in discount rate assumptions	224	(475)	3,545
Effect of foreign currency translation on the effect of changes in discount rate assumptions	13	(271)	(368)
Balance, end of period, at current discount rate at balance sheet date	17,435	17,463	24,453
Cumulative amount of fair value hedging adjustments	0	11	5
Net liability for future policy benefits	12,874	12,792	18,472
Less: Reinsurance recoverables (Amount due to reinsurer)	(1)	(1)	(10)
Net liability for future policy benefits, net of reinsurance	12,875	12,793	18,482
Undiscounted - Expected future gross premiums	9,331	9,369	11,097
Undiscounted - Expected future benefit payments	28,130	28,507	32,372
Discounted - Expected future gross premiums	8,067	8,086	10,377
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 17,435	$ 17,463	$ 24,453
Weighted-average duration of the liability	17 years	15 years	18 years
Weighted -average interest accretion (original locked-in) rate	2.50%	2.30%	2.30%
Weighted-average current discount rate at balance sheet date	2.60%	2.70%	1.50%
Deferred Profit Liability Offset to Cash Flow Assumption Update		$ (13)	$ 1
Deferred Profit Liability Offset to Actual Versus Expected			(6)
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	$ 21,181	26,543	30,327
Balance, beginning of period, at original discount rate	22,594	25,937	29,456
Effect of changes in cash flow assumptions	867	24	64
Effect of actual variances from expected experience	(158)	297	101
Adjusted balance	23,303	26,258	29,621
Issuances	1,030	1,387	1,488
Interest accrual	236	250	311
Net premiums collected	(2,016)	(2,160)	(2,509)
Effect of foreign currency translation	(1,321)	(3,141)	(2,974)
Ending balance at original discount rate	21,232	22,594	25,937
Effect of changes in discount rate assumptions	(1,449)	(1,341)	674
Effect of foreign currency translation on the effect of changes in discount rate assumptions	52	(72)	(68)
Balance, end of period, at current discount rate at balance sheet date	19,835	21,181	26,543
Balance, beginning of period, at current discount rate at balance sheet date	30,879	41,874	46,282
Balance, beginning of period, at original discount rate	37,189	41,517	45,296
Effect of changes in cash flow assumptions	898	(7)	126
Effect of actual variances from expected experience	(180)	363	105
Adjusted balance	37,907	41,873	45,527
Issuances	1,028	1,387	1,487
Interest accrual	485	498	578
Benefit payments	(1,279)	(1,613)	(1,458)
Effect of foreign currency translation	(2,131)	(4,956)	(4,617)
Ending balance at original discount rate	36,010	37,189	41,517
Effect of changes in discount rate assumptions	(5,793)	(6,291)	394
Effect of foreign currency translation on the effect of changes in discount rate assumptions	263	(19)	(37)
Balance, end of period, at current discount rate at balance sheet date	30,480	30,879	41,874
Cumulative amount of fair value hedging adjustments	67	342	68
Net liability for future policy benefits	10,712	10,040	15,399
Less: Reinsurance recoverables (Amount due to reinsurer)	142	143	(11)
Net liability for future policy benefits, net of reinsurance	10,570	9,897	15,410
Undiscounted - Expected future gross premiums	41,734	43,440	49,959
Undiscounted - Expected future benefit payments	47,046	48,147	53,327
Discounted - Expected future gross premiums	34,356	36,179	45,872
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 30,480	$ 30,879	$ 41,874
Weighted-average duration of the liability	25 years	17 years	30 years
Weighted -average interest accretion (original locked-in) rate	1.70%	1.70%	1.70%
Weighted-average current discount rate at balance sheet date	2.50%	2.70%	1.40%
Deferred Profit Liability Offset to Cash Flow Assumption Update	$ (10)	$ 44	$ (69)
Deferred Profit Liability Offset to Actual Versus Expected	4	(20)	(58)
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	0
Balance, beginning of period, at original discount rate	0	0	0
Effect of changes in cash flow assumptions	0	0	0
Effect of actual variances from expected experience	0	1	1
Adjusted balance	0	1	1
Issuances	1,045	714	415
Interest accrual	29	(3)	(6)
Net premiums collected	(1,074)	(712)	(410)
Ending balance at original discount rate	0	0	0
Balance, end of period, at current discount rate at balance sheet date	0	0	0
Balance, beginning of period, at current discount rate at balance sheet date	9,265	7,343	10,517
Balance, beginning of period, at original discount rate	8,240	6,851	7,649
Effect of changes in cash flow assumptions	(5)	(8)	(37)
Effect of actual variances from expected experience	(31)	(32)	2
Adjusted balance	8,204	6,811	7,614
Issuances	1,153	757	491
Interest accrual	341	286	294
Benefit payments	(671)	(560)	(749)
Inflation adjustment	415	896	464
Effect of foreign currency translation	(193)	50	(1,263)
Ending balance at original discount rate	9,249	8,240	6,851
Effect of changes in discount rate assumptions	391	1,026	658
Effect of foreign currency translation on the effect of changes in discount rate assumptions	(3)	(1)	(166)
Balance, end of period, at current discount rate at balance sheet date	9,637	9,265	7,343
Net liability for future policy benefits	9,637	9,265	7,343
Undiscounted - Expected future benefit payments	13,994	12,675	10,712
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 9,637	$ 9,265	$ 7,343
Weighted-average duration of the liability	11 years	11 years	11 years
Weighted -average interest accretion (original locked-in) rate	3.60%	3.90%	4.20%
Weighted-average current discount rate at balance sheet date	3.30%	2.70%	3.20%
Deferred Profit Liability Offset to Cash Flow Assumption Update	$ 4	$ 7	$ 30
Deferred Profit Liability Offset to Actual Versus Expected		20	(28)
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	5,775	7,058	7,142
Balance, beginning of period, at original discount rate	5,807	5,699	5,516
Effect of changes in cash flow assumptions	(152)	272	270
Effect of actual variances from expected experience	199	120	183
Adjusted balance	5,854	6,091	5,969
Interest accrual	294	298	287
Net premiums collected	(582)	(582)	(557)
Ending balance at original discount rate	5,566	5,807	5,699
Effect of changes in discount rate assumptions	121	(32)	1,359
Balance, end of period, at current discount rate at balance sheet date	5,687	5,775	7,058
Balance, beginning of period, at current discount rate at balance sheet date	19,619	27,627	28,483
Balance, beginning of period, at original discount rate	20,165	19,406	18,586
Effect of changes in cash flow assumptions	(190)	301	276
Effect of actual variances from expected experience	223	115	188
Adjusted balance	20,198	19,822	19,050
Interest accrual	1,070	1,043	998
Benefit payments	(774)	(700)	(642)
Ending balance at original discount rate	20,494	20,165	19,406
Effect of changes in discount rate assumptions	433	(546)	8,221
Balance, end of period, at current discount rate at balance sheet date	20,927	19,619	27,627
Other adjustments	0	1	0
Net liability for future policy benefits	15,240	13,845	20,569
Undiscounted - Expected future gross premiums	10,603	11,201	11,404
Undiscounted - Expected future benefit payments	45,016	45,872	45,835
Discounted - Expected future gross premiums	7,139	7,200	9,049
Discounted - Expected future benefit payments (at current discount rate at balance sheet date)	$ 20,927	$ 19,619	$ 27,627
Weighted-average duration of the liability	15 years	15 years	18 years
Weighted -average interest accretion (original locked-in) rate	5.40%	5.50%	5.50%
Weighted-average current discount rate at balance sheet date	5.20%	5.60%	3.00%