Future Policy Benefits - FBP Income Statement (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	$ 3,046	$ 4,165
Interest Expense (2)	1,327	1,200
Variable Annuity [Member] | U.S.
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	245	1,373
Interest Expense (2)	703	587
Whole and Term Life & Endowments | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	282	331
Interest Expense (2)	80	87
Accident and Health Insurance Product Line | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	908	1,010
Interest Expense (2)	64	65
Fixed Annuity | Latin America
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	296	146
Interest Expense (2)	83	71
Long-term Care | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	183	183
Interest Expense (2)	191	183
Fixed Annuity for Deferred Profit Liabilities | Latin America
Principal Transaction Revenue [Line Items]
Interest Expense (2)	6	5
Fixed Annuity for Deferred Profit Liabilities | U.S.
Principal Transaction Revenue [Line Items]
Interest Expense (2)	40	38
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	7	6
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Principal Transaction Revenue [Line Items]
Interest Expense (2)	4	4
Variable Life | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	5	6
Interest Expense (2)	5	6
Universal And Variable Life Contracts [Member] | Asia
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	(12)	0
Interest Expense (2)	2	2
Universal And Variable Life Contracts [Member] | MetLife Holdings
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	192	196
Interest Expense (2)	30	28
Long-Duration Insurance, Other
Principal Transaction Revenue [Line Items]
Gross Premiums or Assessments (1)	947	920
Interest Expense (2)	$ 112	$ 118