Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 732,167	$ 687,538
U.S.
Segment Reporting Information [Line Items]
Total assets	263,410	248,174
Asia
Segment Reporting Information [Line Items]
Total assets	157,743	146,278
Latin America
Segment Reporting Information [Line Items]
Total assets	76,881	70,417
EMEA
Segment Reporting Information [Line Items]
Total assets	27,462	27,829
MetLife Holdings
Segment Reporting Information [Line Items]
Total assets	172,957	166,872
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 33,714	$ 27,968