Long-term and Short-term Debt (Committed Facilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Collateral financing arrangement	$ 993	$ 1,060
Committed Credit Facility Three [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont and MetLife, Inc.
Expiration	Dec. 28, 2024
Line of Credit Facility, Maximum Borrowing Capacity	$ 400
Letters of Credit Issued	396
Collateral financing arrangement	0
Unused Commitments	$ 4
Committed Credit Facility Six [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont and MetLife, Inc.
Expiration	Dec. 31, 2037
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,896
Letters of Credit Issued	2,460
Collateral financing arrangement	0
Unused Commitments	436
Committed Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	3,296
Letters of Credit Issued	2,856
Collateral financing arrangement	0
Unused Commitments	440
Brighthouse Financial, Inc | Committed Credit Facility Six [Member]
Debt Instrument [Line Items]
Letters of Credit Issued	$ 2,500