Policyholder Account Balances - Amounts on Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Policyholder Account Balance [Line Items]
Policyholder account balance	$ 219,168	$ 219,269
Other Products
Policyholder Account Balance [Line Items]
Policyholder account balance	17,187	17,226
Group Life - Term | Group Benefits
Policyholder Account Balance [Line Items]
Policyholder account balance	7,747	7,692	$ 7,965	$ 8,028
Capital Markets Investment Products and Stable Value GICs | RIS
Policyholder Account Balance [Line Items]
Policyholder account balance	64,269	64,140	63,284	63,723
Annuities and Risk Solutions | RIS
Policyholder Account Balance [Line Items]
Policyholder account balance	18,266	17,711	16,128	15,549
Universal and Variable Universal Life | Asia
Policyholder Account Balance [Line Items]
Policyholder account balance	49,484	49,739	46,770	46,417
Fixed Annuity | Asia
Policyholder Account Balance [Line Items]
Policyholder account balance	36,969	36,863	34,272	32,454
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder account balance	11,129	11,537	12,818	13,286
Variable Annuity | EMEA
Policyholder Account Balance [Line Items]
Policyholder account balance	2,631	2,720	2,845	2,802
Life and Other | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder account balance	$ 11,486	$ 11,641	$ 12,234	$ 12,402