Future Policy Benefits - FPB on Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Net liability for FPBs	$ 201,340	$ 196,406
Fixed & Immediate Annuities | RIS
Net liability for FPBs	67,645	64,324	$ 57,496
Whole and Term Life & Endowments | Asia
Net liability for FPBs	12,661	12,874	11,404
Accident & health insurance | Asia
Net liability for FPBs	10,598	10,712	9,329
Fixed Annuity | Latin America
Net liability for FPBs	10,906	9,637	8,662
Long-term Care | MetLife Holdings
Net liability for FPBs	15,657	15,240	$ 13,025
Fixed & Immediate Annuities for Deferred Profit Liabilities | RIS
Net liability for FPBs	3,754	3,697
Whole and Term Life & Endowments for Deferred Profit Liabilities | Asia
Net liability for FPBs	785	654
Accident and Health Insurance Product Line for Deferred Profit Liabilities | Asia
Net liability for FPBs	913	830
Fixed Annuity for Deferred Profit Liabilities | Latin America
Net liability for FPBs	549	562
Variable Life | Asia
Net liability for FPBs	1,227	1,258
Universal and Variable Universal Life | Asia
Net liability for FPBs	399	424
Universal and Variable Universal Life | MetLife Holdings
Net liability for FPBs	2,471	2,362
Participating Life Insurance Contract | MetLife Holdings
Net liability for FPBs	48,629	49,543
Long-Duration Insurance, Other
Net liability for FPBs	11,340	11,099
Short-Duration Insurance, Other
Net liability for FPBs	$ 13,806	$ 13,190