Future Policy Benefits - FPB Income Statement (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	$ 8,927	$ 9,710
Interest Expense (2)	2,998	2,798
Fixed & Immediate Annuities | RIS
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	2,799	4,246
Interest Expense (2)	1,676	1,526
Whole and Term Life & Endowments | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	600	564
Interest Expense (2)	149	149
Accident & health insurance | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	1,561	1,551
Interest Expense (2)	126	122
Fixed Annuity | Latin America
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	742	499
Interest Expense (2)	179	162
Long-term Care | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	359	362
Interest Expense (2)	412	399
Fixed & Immediate Annuities for Deferred Profit Liabilities | RIS
Principal Transaction Revenue [Line Items]
Interest Expense (2)	91	88
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	21	17
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	11	9
Fixed Annuity for Deferred Profit Liabilities | Latin America
Principal Transaction Revenue [Line Items]
Interest Expense (2)	10	10
Variable Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	72	55
Interest Expense (2)	9	9
Universal and Variable Universal Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	1	(33)
Interest Expense (2)	3	3
Universal and Variable Universal Life | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	317	334
Interest Expense (2)	68	65
Long-Duration Insurance, Other
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	2,476	2,132
Interest Expense (2)	$ 243	$ 239