Future Policy Benefits - FPB Income Statement (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	$ 9,710	$ 8,196
Interest Expense (2)	2,798	2,664
Fixed & Immediate Annuities | RIS
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	4,246	2,592
Interest Expense (2)	1,526	1,411
Whole and Term Life & Endowments | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	564	555
Interest Expense (2)	149	158
Accident & health insurance | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	1,551	1,762
Interest Expense (2)	122	126
Fixed Annuity | Latin America
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	499	529
Interest Expense (2)	162	168
Long-term Care | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	362	366
Interest Expense (2)	399	385
Fixed & Immediate Annuities for Deferred Profit Liabilities | RIS
Principal Transaction Revenue [Line Items]
Interest Expense (2)	88	81
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	17	14
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	9	9
Fixed Annuity for Deferred Profit Liabilities | Latin America
Principal Transaction Revenue [Line Items]
Interest Expense (2)	10	11
Variable Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	55	11
Interest Expense (2)	9	10
Universal and Variable Universal Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	(33)	(14)
Interest Expense (2)	3	3
Universal and Variable Universal Life | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	334	380
Interest Expense (2)	65	61
Long-Duration Insurance, Other
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	2,132	2,015
Interest Expense (2)	$ 239	$ 227