Long-term and Short-term Debt (Committed Facilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Collateral financing arrangement	$ 476	$ 637
Committed Credit Facility Six [Member]
Debt Instrument [Line Items]
Borrowers	MRV and MetLife, Inc.
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,896
Letters of Credit Issued	2,491
Collateral financing arrangement	0
Unused Commitments	405
Committed Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	3,246
Letters of Credit Issued	2,841
Collateral financing arrangement	0
Unused Commitments	$ 405
Committed Credit Facility Three [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont (“MRV”) and MetLife, Inc.
Line of Credit Facility, Maximum Borrowing Capacity	$ 350
Letters of Credit Issued	350
Collateral financing arrangement	0
Unused Commitments	0
Brighthouse Financial, Inc | Committed Credit Facility Six [Member]
Debt Instrument [Line Items]
Letters of Credit Issued	$ 2,500