Segment Information (Earnings) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Revenues
Premiums	$ 10,810	$ 11,628	$ 22,533	$ 21,681
Universal life and investment-type product policy fees	1,259	1,281	2,488	2,529
Net investment income	5,661	5,205	10,546	10,641
Other revenues	679	638	1,366	1,312
Expenses
Policyholder liability remeasurement (gains) losses	5	(10)	(26)	(32)
Interest credited to policyholder account balances	2,400	2,000	4,047	4,290
Amortization of DAC, VOBA and negative VOBA	528	493	1,047	995
Interest expense on debt	269	257	527	521
Provision for income tax expense (benefit)	245	249	649	419
Adjusted earnings	$ 1,393	$ 1,662	$ 2,808	$ 3,063
Group Benefits
Expenses
Net investment income from equity method investments	0.00%	0.00%	0.00%	1.00%
RIS
Expenses
Net investment income from equity method investments	4.00%	4.00%	5.00%	4.00%
Asia
Expenses
Net investment income from equity method investments	10.00%	12.00%	10.00%	10.00%
MetLife Holdings
Expenses
Net investment income from equity method investments	3.00%	5.00%	4.00%	5.00%
Operating Segments
Expenses
Adjusted earnings	$ 1,595	$ 1,848	$ 3,192	$ 3,423
Operating Segments | Group Benefits
Revenues
Premiums	5,801	5,599	11,564	11,310
Universal life and investment-type product policy fees	240	229	473	451
Net investment income	310	313	625	628
Other revenues	405	382	839	779
Expenses
Policyholder benefits and claims and policyholder dividends	5,161	4,780	10,344	10,016
Policyholder liability remeasurement (gains) losses	(4)	2	(22)	(1)
Interest credited to policyholder account balances	43	48	87	96
Amortization of DAC, VOBA and negative VOBA	7	7	13	13
Interest expense on debt	1	1	1	1
Direct and Allocated Expenses	503	490	1,027	995
Other segment expenses	538	521	1,080	1,015
Provision for income tax expense (benefit)	107	141	204	216
Adjusted earnings	400	533	767	817
Operating Segments | RIS
Revenues
Premiums	1,210	2,448	3,494	3,123
Universal life and investment-type product policy fees	85	73	170	148
Net investment income	2,145	2,117	4,312	4,206
Other revenues	60	61	121	124
Expenses
Policyholder benefits and claims and policyholder dividends	2,043	3,248	5,164	4,719
Policyholder liability remeasurement (gains) losses	1	(23)	(14)	(22)
Interest credited to policyholder account balances	878	838	1,737	1,634
Amortization of DAC, VOBA and negative VOBA	18	16	35	31
Interest expense on debt	3	3	6	7
Direct and Allocated Expenses	80	74	165	154
Other segment expenses	19	25	46	56
Provision for income tax expense (benefit)	90	108	189	213
Adjusted earnings	368	410	769	809
Operating Segments | Asia
Revenues
Premiums	1,278	1,216	2,538	2,513
Universal life and investment-type product policy fees	399	434	805	860
Net investment income	1,210	1,167	2,416	2,275
Other revenues	22	18	37	39
Expenses
Policyholder benefits and claims and policyholder dividends	1,051	988	2,088	2,055
Policyholder liability remeasurement (gains) losses	(12)	(4)	(23)	(36)
Interest credited to policyholder account balances	757	657	1,468	1,304
Amortization of DAC, VOBA and negative VOBA	223	202	439	407
Interest expense on debt	0	0	0	0
Direct and Allocated Expenses	304	272	610	554
Other segment expenses	91	95	183	196
Provision for income tax expense (benefit)	145	176	307	335
Adjusted earnings	350	449	724	872
Operating Segments | Latin America
Revenues
Premiums	1,260	1,122	2,424	2,237
Universal life and investment-type product policy fees	371	373	711	743
Net investment income	445	398	852	784
Other revenues	3	11	12	22
Expenses
Policyholder benefits and claims and policyholder dividends	1,216	1,018	2,307	2,001
Policyholder liability remeasurement (gains) losses	0	(3)	(3)	(11)
Interest credited to policyholder account balances	96	115	194	229
Amortization of DAC, VOBA and negative VOBA	137	129	266	254
Interest expense on debt	4	4	8	7
Direct and Allocated Expenses	143	145	278	285
Other segment expenses	166	185	342	379
Provision for income tax expense (benefit)	84	85	156	183
Adjusted earnings	233	226	451	459
Operating Segments | EMEA
Revenues
Premiums	626	536	1,208	1,072
Universal life and investment-type product policy fees	84	77	162	154
Net investment income	61	54	119	108
Other revenues	9	8	17	15
Expenses
Policyholder benefits and claims and policyholder dividends	309	265	586	523
Policyholder liability remeasurement (gains) losses	4	1	4	1
Interest credited to policyholder account balances	20	17	37	36
Amortization of DAC, VOBA and negative VOBA	88	81	182	171
Interest expense on debt	0	0	0	0
Direct and Allocated Expenses	111	104	220	205
Other segment expenses	120	109	240	212
Provision for income tax expense (benefit)	28	21	54	47
Adjusted earnings	100	77	183	154
Operating Segments | MetLife Holdings
Revenues
Premiums	624	692	1,281	1,405
Universal life and investment-type product policy fees	80	94	166	172
Net investment income	964	1,016	1,953	2,026
Other revenues	36	37	73	87
Expenses
Policyholder benefits and claims and policyholder dividends	1,164	1,252	2,364	2,503
Policyholder liability remeasurement (gains) losses	16	17	32	37
Interest credited to policyholder account balances	90	106	178	209
Amortization of DAC, VOBA and negative VOBA	53	57	108	116
Interest expense on debt	3	3	6	7
Direct and Allocated Expenses	158	156	326	321
Other segment expenses	43	60	92	113
Provision for income tax expense (benefit)	33	35	69	72
Adjusted earnings	$ 144	$ 153	$ 298	$ 312