Acquisitions and Dispositions (Acquisitions - Narrative) (Details) (USD $)	12 Months Ended				3 Months Ended	12 Months Ended		3 Months Ended						3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member]	Dec. 31, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member]	Sep. 30, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member]	Dec. 31, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member] Service Marks [Member]	Sep. 30, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member] Encaje Investment Fund A [Member]	Sep. 30, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member] Encaje Investment Fund B [Member]	Sep. 30, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member] Encaje Investment Fund C [Member]	Sep. 30, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member] Encaje Investment Fund D [Member]	Sep. 30, 2013 Acquisition of Administradora de Fondos de Pensiones ProVida SA [Member] Encaje Investment Fund E [Member]	Dec. 31, 2010 American Life Insurance Company (''American Life'') and Delaware American Life Insurance (''DelAm'') [Member]	Dec. 31, 2013 American Life Insurance Company (''American Life'') and Delaware American Life Insurance (''DelAm'') [Member]	Dec. 31, 2012 American Life Insurance Company (''American Life'') and Delaware American Life Insurance (''DelAm'') [Member]	Dec. 31, 2011 American Life Insurance Company (''American Life'') and Delaware American Life Insurance (''DelAm'') [Member]	Dec. 31, 2010 American Life Insurance Company (''American Life'') and Delaware American Life Insurance (''DelAm'') [Member]	Nov. 01, 2010 American Life Insurance Company (''American Life'') and Delaware American Life Insurance (''DelAm'') [Member]
Business Acquisition [Line Items]
Business Acquisition, Name of Acquired Entity			American Life Insurance Company ("American Life") and Delaware American Life Insurance Company ("DelAm"), (American Life, together with DelAm, collectively, "ALICO")			Administradora de Fondos de Pensiones Provida S.A. (“ProVida”)
Liability recognized in purchase accounting for the anticipated and estimated costs associated with restructuring foreign branches into subsidiaries															$ 11,000,000				$ 277,000,000
Business Acquisition, Percentage of Voting Interests Acquired Directly From Seller							64.32%
Business Acquisition, Percentage of Voting Interests Acquired Directly From Publicly Traded Shares							27.06%
Business Acquisition, Percentage of Voting Interests Acquired							91.38%
Payments to Acquire Businesses, Gross						1,900,000,000
Equity Method Investment, Ownership Percentage									1.00%	1.00%	1.00%	1.00%	1.00%
Business Acquisition, Effective Date of Acquisition				Nov. 01, 2010										Nov. 01, 2010				Nov. 01, 2010
Business Combination, Consideration Transferred														16,400,000,000
Business Combination, Reason for Business Combination														The ALICO Acquisition significantly broadened the Company’s diversification by product, distribution and geography, meaningfully accelerated MetLife’s global growth strategy, and provides the opportunity to build an international franchise leveraging the key strengths of ALICO.
Fair value of assets assumed							631,000,000
Fair value of liabilities assumed							159,000,000
Acquisitions of VOBA	947,000,000	55,000,000	11,000,000		941,000,000
Finite-Lived Intangible Asset, Useful Life					15 years
Acquired trade name value	0	0	213,000,000					179,000,000
Goodwill acquired	1,141,000,000	1,000,000	39,000,000		1,100,000,000
Fair value of future service liability							589,000,000
Total revenues from acquiree included in MetLife's total revenues					100,000,000
Income (loss) from continuing operations, net of income tax, from Acquisition included in MetLife's 2013 results					42,000,000
Business Acquisition, Transaction Costs					18,000,000	18,000,000
Business Combination, Integration Related Costs					12,000,000										138,000,000	305,000,000	362,000,000
Separate account assets	317,201,000,000	235,393,000,000					45,200,000,000
Separate account liabilities	317,201,000,000	235,393,000,000					45,200,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets							451,000,000
Deferred income tax assets	6,033,000,000	10,261,000,000					118,000,000
Deferred income tax liabilities	12,319,000,000	18,586,000,000					224,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount							0
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value							176,000,000
Liability For Tax Restructuring Costs, Change in Amount															$ 29,000,000