Long-term and Short-term Debt (Credit Facilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Collateral financing arrangement	$ 476	$ 637
General Credit Facility Three [Member]
Debt Instrument [Line Items]
Borrowers	MetLife, Inc. and MetLife Funding, Inc.
Line of Credit Facility, Maximum Borrowing Capacity	$ 3,000
Letters of Credit Issued	297
Collateral financing arrangement	0
Unused Commitments	$ 2,703