Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total assets	$ 677,576	$ 687,584
Group Benefits
Segment Reporting Information [Line Items]
Total assets	37,076	36,715
RIS
Segment Reporting Information [Line Items]
Total assets	217,290	218,587
Asia
Segment Reporting Information [Line Items]
Total assets	154,296	157,206
Latin America
Segment Reporting Information [Line Items]
Total assets	66,142	69,177
EMEA
Segment Reporting Information [Line Items]
Total assets	18,742	18,596
MetLife Holdings
Segment Reporting Information [Line Items]
Total assets	146,621	148,524
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 37,409	$ 38,779