Policyholder Account Balances - Amounts on Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021	Jan. 01, 2021
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 214,413	$ 210,597			$ 211,737
Other Products
Policyholder Account Balance [Line Items]
Policyholder Account Balance	16,552	15,936			19,441
Group Insurance Policy | U.S.
Policyholder Account Balance [Line Items]
Policyholder Account Balance	7,875	8,028	$ 8,056	$ 7,893	7,586
CapitalMarketsInvestmentProductsandStableValueGICs | U.S.
Policyholder Account Balance [Line Items]
Policyholder Account Balance	64,103	63,723	64,595	62,521	62,908
Annuities and Risk Solutions | U.S.
Policyholder Account Balance [Line Items]
Policyholder Account Balance	16,693	15,549	14,439	14,431	13,643
Universal And Variable Life Contracts [Member] | Asia
Policyholder Account Balance [Line Items]
Policyholder Account Balance	46,851	46,417	45,359	46,590	43,868
Fixed Annuity | Asia
Policyholder Account Balance [Line Items]
Policyholder Account Balance	35,124	32,454	30,149	30,976	31,422
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder Account Balance	12,410	13,286	13,985	14,398	15,234
Variable Annuity [Member] | EMEA
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,761	2,802	3,134	4,215	4,779
Life and Other | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 12,044	$ 12,402	$ 12,607	$ 12,699	$ 12,856