Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Separate account assets	$ 188,445	$ 175,556
Separate account liabilities	188,445	175,556
Total assets	740,463	687,538
U.S.
Segment Reporting Information [Line Items]
Separate account assets	75,929	71,436
Separate account liabilities	75,929	71,436
Total assets	266,174	248,174
Asia
Segment Reporting Information [Line Items]
Separate account assets	9,250	8,849
Separate account liabilities	9,250	8,849
Total assets	161,018	146,278
Latin America
Segment Reporting Information [Line Items]
Separate account assets	52,018	47,757
Separate account liabilities	52,018	47,757
Total assets	75,069	70,417
EMEA
Segment Reporting Information [Line Items]
Separate account assets	5,639	5,306
Separate account liabilities	5,639	5,306
Total assets	27,281	27,829
MetLife Holdings
Segment Reporting Information [Line Items]
Separate account assets	45,609	42,208
Separate account liabilities	45,609	42,208
Total assets	175,199	166,872
Corporate & Other
Segment Reporting Information [Line Items]
Separate account assets	0	0
Separate account liabilities	0	0
Total assets	$ 35,722	$ 27,968