Future Policy Benefits - FPB Income Statement (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	$ 3,208	$ 3,046
Interest Expense (2)	1,397	1,327
Fixed & Immediate Annuities | RIS
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	344	245
Interest Expense (2)	759	703
Whole and Term Life & Endowments | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	290	282
Interest Expense (2)	76	80
Accident & health insurance | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	811	908
Interest Expense (2)	62	64
Fixed Annuity | Latin America
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	261	296
Interest Expense (2)	81	83
Long-term Care | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	181	183
Interest Expense (2)	198	191
Fixed & Immediate Annuities for Deferred Profit Liabilities | RIS
Principal Transaction Revenue [Line Items]
Interest Expense (2)	44	40
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	9	7
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	5	4
Fixed Annuity for Deferred Profit Liabilities | Latin America
Principal Transaction Revenue [Line Items]
Interest Expense (2)	5	6
Variable Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	29	5
Interest Expense (2)	4	5
Universal and Variable Universal Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	(33)	(12)
Interest Expense (2)	1	2
Universal and Variable Universal Life | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	167	192
Interest Expense (2)	32	30
Long-Duration Insurance, Other
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	1,158	947
Interest Expense (2)	$ 121	$ 112