Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill Rollforward and by Segment
Goodwill - beginning of period	$ 10,792	$ 9,988	$ 10,102
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net - beginning of period	10,112	9,308	9,422
Acquisitions		932	19
Disposition			(71)
Effect of foreign currency translation and other	(577)	200	(62)
Goodwill - end of period	10,215	10,792	9,988
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net - end of period	9,535	10,112	9,308
Metropolitan Property And Casualty Insurance Company [Member]
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill	328
Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		328
U.S.
Goodwill Rollforward and by Segment
Goodwill - beginning of period	2,070	1,466	1,451
Accumulated impairment	0	0	0
Total goodwill, net - beginning of period	2,070	1,466	1,451
Acquisitions		932	15
Disposition			0
Effect of foreign currency translation and other	0	0	0
Goodwill - end of period	2,070	2,070	1,466
Accumulated impairment	0	0	0
Total goodwill, net - end of period	2,070	2,070	1,466
U.S. | Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		328
Asia
Goodwill Rollforward and by Segment
Goodwill - beginning of period	4,763	4,636	4,690
Accumulated impairment	0	0	0
Total goodwill, net - beginning of period	4,763	4,636	4,690
Acquisitions		0	4
Disposition			(71)
Effect of foreign currency translation and other	(211)	127	13
Goodwill - end of period	4,552	4,763	4,636
Accumulated impairment	0	0	0
Total goodwill, net - end of period	4,552	4,763	4,636
Asia | Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		0
Latin America
Goodwill Rollforward and by Segment
Goodwill - beginning of period	1,143	1,099	1,172
Accumulated impairment	0	0	0
Total goodwill, net - beginning of period	1,143	1,099	1,172
Acquisitions		0	0
Disposition			0
Effect of foreign currency translation and other	(166)	44	(73)
Goodwill - end of period	977	1,143	1,099
Accumulated impairment	0	0	0
Total goodwill, net - end of period	977	1,143	1,099
Latin America | Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		0
EMEA
Goodwill Rollforward and by Segment
Goodwill - beginning of period	1,146	1,117	1,119
Accumulated impairment	0	0	0
Total goodwill, net - beginning of period	1,146	1,117	1,119
Acquisitions		0	0
Disposition			0
Effect of foreign currency translation and other	(200)	29	(2)
Goodwill - end of period	946	1,146	1,117
Accumulated impairment	0	0	0
Total goodwill, net - end of period	946	1,146	1,117
EMEA | Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		0
MetLife Holdings
Goodwill Rollforward and by Segment
Goodwill - beginning of period	1,567	1,567	1,567
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net - beginning of period	887	887	887
Acquisitions		0	0
Disposition			0
Effect of foreign currency translation and other	0	0	0
Goodwill - end of period	1,567	1,567	1,567
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net - end of period	887	887	887
MetLife Holdings | Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		0
Corporate & Other
Goodwill Rollforward and by Segment
Goodwill - beginning of period	103	103	103
Accumulated impairment	0	0	0
Total goodwill, net - beginning of period	103	103	103
Acquisitions		0	0
Disposition			0
Effect of foreign currency translation and other	0	0	0
Goodwill - end of period	103	103	103
Accumulated impairment	0	0	0
Total goodwill, net - end of period	103	103	103
Corporate & Other | Goodwill
Goodwill Rollforward and by Segment
Disposal Group, Including Discontinued Operation, Goodwill		0
JAPAN
Goodwill Rollforward and by Segment
Total goodwill, net - beginning of period	4,600	4,500
Total goodwill, net - end of period	$ 4,400	$ 4,600	$ 4,500