Goodwill (Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill Rollforward and by Segment
Goodwill	$ 9,900	$ 9,897	$ 10,292
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net	9,220	9,217	9,612
Acquisition	103
Dispositions	(16)	(42)
Effect of foreign currency translation and other	283	45	(395)
Goodwill	10,270	9,900	9,897
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net	9,590	9,220	9,217
U.S.
Goodwill Rollforward and by Segment
Goodwill	1,451	1,451	1,451
Accumulated impairment	0	0	0
Total goodwill, net	1,451	1,451	1,451
Acquisition	0
Dispositions	0	0
Effect of foreign currency translation and other	0	0	0
Goodwill	1,451	1,451	1,451
Accumulated impairment	0	0	0
Total goodwill, net	1,451	1,451	1,451
Asia
Goodwill Rollforward and by Segment
Goodwill	4,596	4,508	4,615
Accumulated impairment	0	0	0
Total goodwill, net	4,596	4,508	4,615
Acquisition	0
Dispositions	0	0
Effect of foreign currency translation and other	77	88	(107)
Goodwill	4,673	4,596	4,508
Accumulated impairment	0	0	0
Total goodwill, net	4,673	4,596	4,508
Latin America
Goodwill Rollforward and by Segment
Goodwill	1,226	1,186	1,385
Accumulated impairment	0	0	0
Total goodwill, net	1,226	1,186	1,385
Acquisition	0
Dispositions	(16)	0
Effect of foreign currency translation and other	96	40	(199)
Goodwill	1,306	1,226	1,186
Accumulated impairment	0	0	0
Total goodwill, net	1,306	1,226	1,186
EMEA
Goodwill Rollforward and by Segment
Goodwill	1,060	1,143	1,232
Accumulated impairment	0	0	0
Total goodwill, net	1,060	1,143	1,232
Acquisition	0
Dispositions	0	0
Effect of foreign currency translation and other	110	(83)	(89)
Goodwill	1,170	1,060	1,143
Accumulated impairment	0	0	0
Total goodwill, net	1,170	1,060	1,143
MetLife Holdings
Goodwill Rollforward and by Segment
Goodwill	1,567	1,567	1,567
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net	887	887	887
Acquisition	0
Dispositions	0	0
Effect of foreign currency translation and other	0	0	0
Goodwill	1,567	1,567	1,567
Accumulated impairment	(680)	(680)	(680)
Total goodwill, net	887	887	887
Corporate & Other
Goodwill Rollforward and by Segment
Goodwill	0	42	42
Accumulated impairment	0	0	0
Total goodwill, net	0	42	42
Acquisition	103
Dispositions	0	(42)
Effect of foreign currency translation and other	0	0	0
Goodwill	103	0	42
Accumulated impairment	0	0	0
Total goodwill, net	$ 103	$ 0	$ 42

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e961-128460

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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