Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Separate account assets	$ 199,970	$ 188,445
Separate account liabilities	199,970	188,445
Total assets	795,146	740,463
U.S.
Segment Reporting Information [Line Items]
Separate account assets	85,316	75,929
Separate account liabilities	85,316	75,929
Total assets	291,483	266,174
Asia
Segment Reporting Information [Line Items]
Separate account assets	10,825	9,250
Separate account liabilities	10,825	9,250
Total assets	173,884	161,018
Latin America
Segment Reporting Information [Line Items]
Separate account assets	50,073	52,018
Separate account liabilities	50,073	52,018
Total assets	75,047	75,069
EMEA
Segment Reporting Information [Line Items]
Separate account assets	6,083	5,639
Separate account liabilities	6,083	5,639
Total assets	28,372	27,281
MetLife Holdings
Segment Reporting Information [Line Items]
Separate account assets	47,673	45,609
Separate account liabilities	47,673	45,609
Total assets	184,566	175,199
Corporate & Other
Segment Reporting Information [Line Items]
Separate account assets	0	0
Separate account liabilities	0	0
Total assets	$ 41,794	$ 35,722