Long-term and Short-term Debt (Details 3) (USD $) In Millions, unless otherwise specified				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Committed Credit Facility Total [Member]	Dec. 31, 2012 Committed Credit Facility One [Member]	Dec. 31, 2012 Committed Credit Facility Two [Member]	Dec. 31, 2012 Committed Credit Facility Three [Member]	Dec. 31, 2012 Committed Credit Facility Four [Member]	Dec. 31, 2012 Committed Credit Facility Five [Member]	Dec. 31, 2012 Committed Credit Facility Six [Member]	Dec. 31, 2012 Committed Credit Facility Seven [Member]
Debt Instrument [Line Items]
Borrowers				MetLife, Inc.	Exeter Reassurance Company, Ltd., MetLife, Inc., & Missouri Reinsurance, Inc.	MetLife Reinsurance Company of Vermont & MetLife, Inc.	Exeter Reassurance Company, Ltd.	MetLife Reinsurance Company of South Carolina & MetLife, Inc.	MetLife Reinsurance Company of Vermont & MetLife, Inc.	MetLife Reinsurance Company of Vermont & MetLife, Inc.
Expiration				Aug. 31, 2013	Jun. 30, 2016	Dec. 31, 2020	Dec. 31, 2027	Jun. 30, 2037	Dec. 31, 2037	Sep. 30, 2038
Line of Credit Facility, Maximum Borrowing Capacity			$ 12,446	$ 300	$ 500	$ 350	$ 650	$ 3,500	$ 2,896	$ 4,250
Letter of Credit Issuances			5,538	300	490	350	555	0	1,825	2,018
Collateral financing arrangements	4,196	4,647	2,797	0	0	0	0	2,797	0	0
Unused Commitments			$ 4,111	$ 0	$ 10	$ 0	$ 95	$ 703	$ 1,071	$ 2,232