Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total assets	$ 704,976	$ 687,584
Group Benefits
Segment Reporting Information [Line Items]
Total assets	36,894	36,715
RIS
Segment Reporting Information [Line Items]
Total assets	229,709	218,587
Asia
Segment Reporting Information [Line Items]
Total assets	162,531	157,206
Latin America
Segment Reporting Information [Line Items]
Total assets	73,419	69,177
EMEA
Segment Reporting Information [Line Items]
Total assets	19,653	18,596
MetLife Holdings
Segment Reporting Information [Line Items]
Total assets	146,403	148,524
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 36,367	$ 38,779