Future Policy Benefits - FPB Income Statement (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	$ 12,993	$ 20,663
Interest Expense (2)	4,018	3,623
Fixed & Immediate Annuities | U.S.
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	4,433	12,627
Interest Expense (2)	2,145	1,811
Whole and Term Life & Endowments | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	841	880
Interest Expense (2)	235	244
Accident and Health Insurance Product Line | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	2,580	2,773
Interest Expense (2)	188	189
Fixed Annuity | Latin America
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	799	549
Interest Expense (2)	242	216
Long-term Care | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	547	550
Interest Expense (2)	579	555
Fixed & Immediate Annuities for Deferred Profit Liabilities | U.S.
Principal Transaction Revenue [Line Items]
Interest Expense (2)	124	115
Fixed Annuity for Deferred Profit Liabilities | Latin America
Principal Transaction Revenue [Line Items]
Interest Expense (2)	17	15
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	22	19
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	13	12
Variable Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	60	37
Interest Expense (2)	15	16
Universal And Variable Life Contracts [Member] | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	(20)	(8)
Interest Expense (2)	5	6
Universal And Variable Life Contracts [Member] | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	559	584
Interest Expense (2)	92	86
Long-Duration Insurance, Other
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	3,194	2,671
Interest Expense (2)	$ 341	$ 339