Future Policy Benefits - FPB on Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021
Net liability for future policy benefits	$ 196,406	$ 187,222		$ 224,358
Fixed & Immediate Annuities | Retirement and Income Solutions
Net liability for future policy benefits	64,324	58,495	$ 63,681
Whole and Term Life & Endowments | Asia
Net liability for future policy benefits	12,874	12,792	18,472
Accident & health insurance | Asia
Net liability for future policy benefits	10,712	10,040	15,399
Fixed Annuity | Latin America
Net liability for future policy benefits	9,637	9,265	7,343
Long-term Care | MetLife Holdings
Net liability for future policy benefits	15,240	13,845	$ 20,569
Fixed & Immediate Annuities for Deferred Profit Liabilities | Retirement and Income Solutions
Net liability for future policy benefits	3,697	3,327
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Net liability for future policy benefits	654	510
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Net liability for future policy benefits	830	760
Fixed Annuity for Deferred Profit Liabilities | Latin America
Net liability for future policy benefits	562	560
Variable Life | Asia
Net liability for future policy benefits	1,258	1,381
Universal and Variable Universal Life | Asia
Net liability for future policy benefits	424	455
Universal and Variable Universal Life | MetLife Holdings
Net liability for future policy benefits	2,362	2,156
Participating Life Insurance Contract | MetLife Holdings
Net liability for future policy benefits	49,543	50,371
Long-Duration Insurance, Other
Net liability for future policy benefits	11,099	10,101
Short-Duration Insurance, Other
Net liability for future policy benefits	$ 13,190	$ 13,164