Policyholder Account Balances - Amounts on Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Jan. 01, 2021
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 212,569	$ 210,597			$ 211,737
Other Products
Policyholder Account Balance [Line Items]
Policyholder Account Balance	16,253	15,936			19,441
Group Insurance Policy | U.S.
Policyholder Account Balance [Line Items]
Policyholder Account Balance	7,965	8,028	$ 8,034	$ 7,893	7,586
CapitalMarketsInvestmentProductsandStableValueGICs | U.S.
Policyholder Account Balance [Line Items]
Policyholder Account Balance	63,284	63,723	66,165	62,521	62,908
Annuities and Risk Solutions | U.S.
Policyholder Account Balance [Line Items]
Policyholder Account Balance	16,128	15,549	14,385	14,431	13,643
Universal And Variable Life Contracts [Member] | Asia
Policyholder Account Balance [Line Items]
Policyholder Account Balance	46,770	46,417	46,955	46,590	43,868
Fixed Annuity | Asia
Policyholder Account Balance [Line Items]
Policyholder Account Balance	34,272	32,454	31,477	30,976	31,422
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder Account Balance	12,818	13,286	14,182	14,398	15,234
Variable Annuity [Member] | EMEA
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,845	2,802	3,769	4,215	4,779
Life and Other | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 12,234	$ 12,402	$ 12,676	$ 12,699	$ 12,856