Contingencies, Commitments and Guarantees (Details) (USD $)	9 Months Ended										9 Months Ended			12 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Commitments to Extend Credit [Member]	Dec. 31, 2011 Commitments to Extend Credit [Member]	Sep. 30, 2012 Interest Rate Lock Commitments [Member]	Dec. 31, 2011 Interest Rate Lock Commitments [Member]	Sep. 30, 2012 Mortgage Loan Commitments [Member]	Dec. 31, 2011 Mortgage Loan Commitments [Member]	Sep. 30, 2012 Minimum [Member]	Sep. 30, 2012 Maximum [Member]	Sep. 30, 2012 Superfund Site Settlement Agreements [Member] Claims	Sep. 30, 2012 Asbestos Related Claims [Member] Claims	Sep. 30, 2011 Asbestos Related Claims [Member] Claims	Dec. 31, 2011 Asbestos Related Claims [Member] Claims	Sep. 30, 2012 Merrill Haviland, et Al v. Metropolitan Life Insurance Company [Member] Plaintiffs	Sep. 30, 2012 Total Asset Recovery Services, LLC Minnesota v. MetLife, Inc et Al [Member] Contracts	Sep. 30, 2012 Total Asset Recovery Services, LLC Illinois v. MetLife, Inc et Al [Member] Contracts	Mar. 31, 2012 Unclaimed Property [Member]	Sep. 30, 2011 Unclaimed Property [Member]	Sep. 30, 2012 Derivative Actions And Demands [Member] Plaintiffs	Sep. 30, 2012 Met Life Bank Mortgage Regulatory and Law Enforcement Authorities' Inquiries [Member]
Loss Contingencies
After tax charge for the multistate examination payment and the expected acceleration of benefit payments to policyholders under settlements																		$ 52,000,000
Asbestos-Related Claims												3,909	3,750	4,972
Number of regulatory matters and other claims											2
After tax charge to increase reserves in connection with identification of potential life insurance claims through database searches																			117,000,000
Multistate examination payment to be allocated among settling states																		40,000,000
Damages Sought											less than $1 million and an additional amount
Damages Sought																228,000,000
Assumed average face amount of life insurance policies in lawsuit																130,000
Number of life insurance contracts named in legal action																584	4,766
Number of plaintiffs															45					5
Loss Contingency, Range of Possible Loss, Maximum																					3,200,000
Maximum estimate of aggregate costs to resolve matter											1,000,000
Maximum estimate of costs for environmental testing											100,000
The approximate amount of the aggregate range of reasonably possible losses in excess of amounts accrued for matters as to which an estimate can be made									0	145,000,000
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability			1,500,000,000	1,400,000,000	0	5,600,000,000	2,900,000,000	4,100,000,000
Contingencies, Commitments and Guarantees (Textuals) [Abstract]
Number of years over which commitments will be invested in partnerships	5 years
Commitments to fund partnership investments	3,500,000,000	4,000,000,000
Liabilities for indemnities, guarantees and commitments	6,000,000	5,000,000
Minimum indemnities and guarantees contractual limitiation	less than $1 million
Maximum indemnities and guarantees contractual limitiation	800,000,000
Cumulative maximum indemnities and guarantees contractual limitiation	$ 2,300,000,000