Policyholder Account Balances - Amounts on Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Policyholder Account Balance [Line Items]
Policyholder account balance	$ 225,623	$ 221,445
Other Products
Policyholder Account Balance [Line Items]
Policyholder account balance	16,847	16,566
Group Life - Term | Group Benefits
Policyholder Account Balance [Line Items]
Policyholder account balance	7,647	7,632	$ 7,747	$ 7,692
Capital Markets Investment Products and Stable Value GICs | RIS
Policyholder Account Balance [Line Items]
Policyholder account balance	65,147	63,715	64,269	64,140
Annuities and Risk Solutions | RIS
Policyholder Account Balance [Line Items]
Policyholder account balance	21,568	20,699	18,266	17,711
Universal and Variable Universal Life | Asia
Policyholder Account Balance [Line Items]
Policyholder account balance	51,963	50,801	49,484	49,739
Fixed Annuity | Asia
Policyholder Account Balance [Line Items]
Policyholder account balance	39,301	38,421	36,969	36,863
Fixed Annuity | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder account balance	9,859	10,142	11,129	11,537
Variable Annuity | EMEA
Policyholder Account Balance [Line Items]
Policyholder account balance	2,305	2,337	2,631	2,720
Life and Other | MetLife Holdings
Policyholder Account Balance [Line Items]
Policyholder account balance	$ 10,986	$ 11,132	$ 11,486	$ 11,641