Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 742,812	$ 687,538
U.S.
Segment Reporting Information [Line Items]
Total assets	267,428	248,174
Asia
Segment Reporting Information [Line Items]
Total assets	160,798	146,278
Latin America
Segment Reporting Information [Line Items]
Total assets	75,640	70,417
EMEA
Segment Reporting Information [Line Items]
Total assets	26,418	27,829
MetLife Holdings
Segment Reporting Information [Line Items]
Total assets	176,410	166,872
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 36,118	$ 27,968