Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total assets	$ 724,284	$ 759,708
U.S.
Segment Reporting Information [Line Items]
Total assets	271,448	282,741
Asia
Segment Reporting Information [Line Items]
Total assets	162,336	169,291
Latin America
Segment Reporting Information [Line Items]
Total assets	62,509	59,763
EMEA
Segment Reporting Information [Line Items]
Total assets	23,039	27,038
MetLife Holdings
Segment Reporting Information [Line Items]
Total assets	169,126	179,551
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 35,826	$ 41,324