Future Policy Benefits - FPB Income Statement (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	$ 13,602	$ 12,993
Interest Expense (2)	4,241	4,018
Fixed & Immediate Annuities | RIS
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	5,098	4,433
Interest Expense (2)	2,326	2,145
Whole and Term Life & Endowments | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	850	841
Interest Expense (2)	224	235
Accident & health insurance | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	2,324	2,580
Interest Expense (2)	185	188
Fixed Annuity | Latin America
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	773	799
Interest Expense (2)	240	242
Long-term Care | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	543	547
Interest Expense (2)	599	579
Fixed & Immediate Annuities for Deferred Profit Liabilities | RIS
Principal Transaction Revenue [Line Items]
Interest Expense (2)	133	124
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	27	22
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	15	13
Fixed Annuity for Deferred Profit Liabilities | Latin America
Principal Transaction Revenue [Line Items]
Interest Expense (2)	15	17
Variable Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	85	60
Interest Expense (2)	13	15
Universal and Variable Universal Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	(32)	(20)
Interest Expense (2)	4	5
Universal and Variable Universal Life | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	492	559
Interest Expense (2)	98	92
Long-Duration Insurance, Other
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	3,469	3,194
Interest Expense (2)	$ 362	$ 341