Fair Value (Details Textuals) (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Fair Value (Textuals) [Abstract]
Additions to MSRs	$ 37	$ 47	$ 92	$ 106
Reduction due to loan payments or sales	(27)	(63)	(60)	(86)
Changes in valuation model inputs or assumptions affecting MSRs	(75)	(183)	(18)	(238)
Call options in equity securities	(74)		(74)		(62)
Call options in fixed maturity securities	6		6		5
Transfers between Levels 1 and 2	not significant	not significant	not significant	not significant
Nonperformance risk adjustment income		305
Nonperformance risk adjustment loss				577
Nonperformance risk adjustment resulting in a reduction to basic net income available to MetLife Inc.'s common shareholder per common share		$ 0.70		$ 0.70
Nonperformance risk adjustment resulting in a reduction to diluted net income available to MetLife Inc.'s common shareholder per common share		$ 0.69		$ 0.70
Fixed maturity securities [Member]
Fair Value (Textuals) [Abstract]
Transfer Into Level 3	756	1,088	653	1,214
Transfer Out of Level 3	(3,210)	(1,063)	(4,594)	(1,336)
Separate account assets [Member]
Fair Value (Textuals) [Abstract]
Transfer Into Level 3	1	12	9	49
Transfer Out of Level 3	(122)	(182)	(196)	(222)
Other limited partnership interests [Member]
Fair Value (Textuals) [Abstract]
Unfunded commitment for investments	1	23	1	23
Real estate joint ventures [Member]
Fair Value (Textuals) [Abstract]
Unfunded commitment for investments	0	11	0	11
Net Derivatives [Member]
Fair Value (Textuals) [Abstract]
Transfer Out of Level 3	$ 0		$ (108)