Policyholder Account Balances - Transition Table (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	$ 219,269	$ 210,597		$ 211,737
Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				(958)
Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				7,519
Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance		203,082			$ 205,176
Other Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	17,226	15,936		19,441
Other Products \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				(170)
Other Products \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				102
Other Products \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					19,509
Group Life - Term \| Group Benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	7,692	8,028	$ 7,893	7,586	7,586
Group Life - Term \| Group Benefits \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Group Life - Term \| Group Benefits \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Group Life - Term \| Group Benefits \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					7,586
Capital Markets Investment Products and Stable Value GICs \| Retirement and Income Solutions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	64,140	63,723	62,521	62,908	62,908
Capital Markets Investment Products and Stable Value GICs \| Retirement and Income Solutions \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Capital Markets Investment Products and Stable Value GICs \| Retirement and Income Solutions \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Capital Markets Investment Products and Stable Value GICs \| Retirement and Income Solutions \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					62,908
Annuities and Risk Solutions \| Retirement and Income Solutions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	17,711	15,549	14,431	13,643	13,643
Annuities and Risk Solutions \| Retirement and Income Solutions \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				(24)
Annuities and Risk Solutions \| Retirement and Income Solutions \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				7,417	7,400
Annuities and Risk Solutions \| Retirement and Income Solutions \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					6,250
Universal and Variable Universal Life \| Asia
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	49,739	46,417	46,590	43,868	43,868
Universal and Variable Universal Life \| Asia \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Universal and Variable Universal Life \| Asia \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Universal and Variable Universal Life \| Asia \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					43,868
Fixed Annuity \| Asia
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	36,863	32,454	30,976	31,422	31,422
Fixed Annuity \| Asia \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Fixed Annuity \| Asia \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Fixed Annuity \| Asia \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					31,422
Fixed Annuity \| MetLife Holdings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	11,537	13,286	14,398	15,234	15,234
Fixed Annuity \| MetLife Holdings \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				(493)
Fixed Annuity \| MetLife Holdings \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Fixed Annuity \| MetLife Holdings \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					15,727
Variable Annuity \| EMEA
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	2,720	2,802	4,215	4,779	4,779
Variable Annuity \| EMEA \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				2
Variable Annuity \| EMEA \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				0
Variable Annuity \| EMEA \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					4,777
Life and Other \| MetLife Holdings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance	$ 11,641	$ 12,402	$ 12,699	12,856	12,856
Life and Other \| MetLife Holdings \| Reclassification of carrying amount of contracts and contract features that are market risk benefits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				(273)
Life and Other \| MetLife Holdings \| Other balance sheet reclassifications upon adoption of the LDTI standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance				$ 0
Life and Other \| MetLife Holdings \| Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Policyholder account balance					$ 13,129