Future Policy Benefits - FPB on Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Jan. 01, 2021
Liability for Future Policy Benefit, before Reinsurance	$ 190,474	$ 187,222		$ 224,358
Variable Annuity [Member] | U.S.
Liability for Future Policy Benefit, before Reinsurance	60,281	58,495	$ 54,590
Whole and Term Life & Endowments | Asia
Liability for Future Policy Benefit, before Reinsurance	12,499	12,792	13,785
Accident and Health Insurance Product Line | Asia
Liability for Future Policy Benefit, before Reinsurance	10,662	10,040	11,108
Fixed Annuity | Latin America
Liability for Future Policy Benefit, before Reinsurance	10,192	9,265	7,675
Long-term Care | MetLife Holdings
Liability for Future Policy Benefit, before Reinsurance	14,498	13,845	$ 14,828
Variable Annuity for Deferred Profit Liabilities | U.S.
Liability for Future Policy Benefit, before Reinsurance	3,417	3,327
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Liability for Future Policy Benefit, before Reinsurance	560	510
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Liability for Future Policy Benefit, before Reinsurance	765	760
Fixed Annuity for Deferred Profit Liabilities | Latin America
Liability for Future Policy Benefit, before Reinsurance	605	560
Variable Life | Asia
Liability for Future Policy Benefit, before Reinsurance	1,243	1,381
Universal And Variable Life Contracts [Member] | Asia
Liability for Future Policy Benefit, before Reinsurance	410	455
Universal And Variable Life Contracts [Member] | MetLife Holdings
Liability for Future Policy Benefit, before Reinsurance	2,268	2,156
Participating Life Insurance Contract | MetLife Holdings
Liability for Future Policy Benefit, before Reinsurance	49,919	50,371
Long-Duration Insurance, Other
Liability for Future Policy Benefit, before Reinsurance	10,076	10,101
Short-Duration Insurance, Other
Liability for Future Policy Benefit, before Reinsurance	$ 13,079	$ 13,164