Long-term and Short-term Debt (Committed Facilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Collateral financing arrangement	$ 766	$ 845
Committed Credit Facility Six [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont and MetLife, Inc.
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,896
Letters of Credit Issued	2,492
Collateral financing arrangement	0
Unused Commitments	404
Committed Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	3,246
Letters of Credit Issued	2,842
Collateral financing arrangement	0
Unused Commitments	$ 404
Committed Credit Facility Three [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont 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