Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 767,583	$ 740,463
U.S.
Segment Reporting Information [Line Items]
Total assets	284,305	266,174
Asia
Segment Reporting Information [Line Items]
Total assets	163,082	161,018
Latin America
Segment Reporting Information [Line Items]
Total assets	70,791	75,069
EMEA
Segment Reporting Information [Line Items]
Total assets	25,915	27,281
MetLife Holdings
Segment Reporting Information [Line Items]
Total assets	179,585	175,199
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 43,905	$ 35,722