Long-term and Short-term Debt (Details 2) (USD $) In Millions, unless otherwise specified				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 General Credit Facility [Member]	Dec. 31, 2012 General Credit Facility One [Member]	Dec. 31, 2012 General Credit Facility Two [Member]
Debt Instrument [Line Items]
Borrowers				MetLife, Inc. and MetLife Funding, Inc.	MetLife, Inc. and MetLife Funding, Inc.
Expiration				Sep. 30, 2017	Aug. 31, 2016
Line of Credit Facility, Maximum Borrowing Capacity			$ 4,000	$ 1,000	$ 3,000
Letter of Credit Issuances			2,568	365	2,203
Collateral financing arrangements	4,196	4,647	0	0	0
Unused Commitments			1,432	635	797
Fees associated with credit facilities				$ 4