Goodwill (Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill Rollforward and by Segment
Goodwill	$ 12,410us-gaap_GoodwillGross	$ 11,886us-gaap_GoodwillGross	$ 12,000us-gaap_GoodwillGross
Accumulated impairment	(1,868)	(1,933)
Goodwill total	10,542us-gaap_Goodwill	9,953us-gaap_Goodwill	11,935us-gaap_Goodwill
Acquisitions (4)		1,141us-gaap_GoodwillAcquiredDuringPeriod	1us-gaap_GoodwillAcquiredDuringPeriod
Dispositions (6)	(70)	(8)
Impairments	0us-gaap_GoodwillImpairmentLoss	0us-gaap_GoodwillImpairmentLoss	1,868us-gaap_GoodwillImpairmentLoss
Effect of foreign currency translation and other	(600)	(544)	(115)
Goodwill	11,740us-gaap_GoodwillGross	12,410us-gaap_GoodwillGross	11,886us-gaap_GoodwillGross
Accumulated impairment	(1,868)	(1,868)	(1,933)
Goodwill total	9,872us-gaap_Goodwill	10,542us-gaap_Goodwill	9,953us-gaap_Goodwill
MetLife Bank [Member]
Goodwill Rollforward and by Segment
Accumulated impairment				(65)
Reduction of goodwill		(65)
Reduction of accumulated impairment		65
Accumulated impairment				(65)
Retail
Goodwill Rollforward and by Segment
Goodwill	3,125	3,125	3,125
Accumulated impairment	(1,692)	(1,692)	0
Goodwill total	1,433	1,433	3,125
Acquisitions (4)		0	0
Dispositions (6)	0	0
Reduction of goodwill		0
Reduction of accumulated impairment		0
Impairments			1,692
Effect of foreign currency translation and other	0	0	0
Goodwill	3,125	3,125	3,125
Accumulated impairment	(1,692)	(1,692)	(1,692)
Goodwill total	1,433	1,433	1,433
Group, Voluntary & Worksite Benefits
Goodwill Rollforward and by Segment
Goodwill	138	138	138
Accumulated impairment	0	0	0
Goodwill total	138	138	138
Acquisitions (4)		0	0
Dispositions (6)	0	0
Reduction of goodwill		0
Reduction of accumulated impairment		0
Impairments			0
Effect of foreign currency translation and other	0	0	0
Goodwill	138	138	138
Accumulated impairment	0	0	0
Goodwill total	138	138	138
Corporate Benefit Funding
Goodwill Rollforward and by Segment
Goodwill	900	900	900
Accumulated impairment	0	0	0
Goodwill total	900	900	900
Acquisitions (4)		0	0
Dispositions (6)	(60)	0
Reduction of goodwill		0
Reduction of accumulated impairment		0
Impairments			0
Effect of foreign currency translation and other	0	0	0
Goodwill	840	900	900
Accumulated impairment	0	0	0
Goodwill total	840	900	900
Latin America
Goodwill Rollforward and by Segment
Goodwill	1,588	527	501
Accumulated impairment	0	0	0
Goodwill total	1,588	527	501
Acquisitions (4)		1,140	0
Dispositions (6)	0	0
Reduction of goodwill		0
Reduction of accumulated impairment		0
Impairments			0
Effect of foreign currency translation and other	(203)	(79)	26
Goodwill	1,385	1,588	527
Accumulated impairment	0	0	0
Goodwill total	1,385	1,588	527
Asia
Goodwill Rollforward and by Segment
Goodwill	4,898	5,387	5,533
Accumulated impairment	0	0	0
Goodwill total	4,898	5,387	5,533
Acquisitions (4)		0	0
Dispositions (6)	(3)	0
Reduction of goodwill		0
Reduction of accumulated impairment		0
Impairments			0
Effect of foreign currency translation and other	(280)	(489)	(146)
Goodwill	4,615	4,898	5,387
Accumulated impairment	0	0	0
Goodwill total	4,615	4,898	5,387
EMEA
Goodwill Rollforward and by Segment
Goodwill	1,356	1,339	1,333
Accumulated impairment	0	0	0
Goodwill total	1,356	1,339	1,333
Acquisitions (4)		1	1
Dispositions (6)	(7)	(8)
Reduction of goodwill		0
Reduction of accumulated impairment		0
Impairments			0
Effect of foreign currency translation and other	(117)	24	5
Goodwill	1,232	1,356	1,339
Accumulated impairment	0	0	0
Goodwill total	1,232	1,356	1,339
Corporate & Other
Goodwill Rollforward and by Segment
Goodwill	405	470	470
Accumulated impairment	(176)	(241)	(65)
Goodwill total	229	229	405
Acquisitions (4)		0	0
Dispositions (6)	0	0
Reduction of goodwill		(65)
Reduction of accumulated impairment		65
Impairments			176
Effect of foreign currency translation and other	0	0	0
Goodwill	405	405	470
Accumulated impairment	(176)	(176)	(241)
Goodwill total	$ 229	$ 229	$ 229

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

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