Pending Disposition of MetLife Poland and Greece (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	$ 7,590		$ 0
Cash and cash equivalents	104	$ 765	0	$ 0
Liabilities held-for-sale	6,844	$ 4,650	$ 0
MetLife Poland and Greece
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	7,590
Cash and cash equivalents	104
Other	309
Liabilities held-for-sale	6,844
Other	145
MetLife Poland and Greece | Fixed Maturities [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	2,235
MetLife Poland and Greece | Contractholder-directed equity securities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	1,125
MetLife Poland and Greece | Other Investments
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	139
MetLife Poland and Greece | Investments
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	3,499
MetLife Poland and Greece | Deferred policy acquisition costs
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	144
MetLife Poland and Greece | Separate Accounts
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	3,534
MetLife Poland and Greece | Future policy benefits [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities held-for-sale	975
MetLife Poland and Greece | Policyholder Account Balances [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities held-for-sale	2,080
MetLife Poland and Greece | Other Policy-Related Balances
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities held-for-sale	110
MetLife Poland and Greece | Separate account liabilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities held-for-sale	$ 3,534