Investments (Net Unrealized Investment Gains Losses) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of net unrealized investment gains (losses) included in accumulated other comprehensive loss
Fixed maturity securities that were temporarily impaired	$ 27,769	$ 16,672
Fixed maturity securities with noncredit OTTI losses in accumulated other comprehensive income (loss)	(110)	(218)	(361)
Total fixed maturity securities	27,659	16,454
Equity securities	631	390
Derivatives	737	375
Other	(12)	(73)
Subtotal	29,015	17,146
Insurance liability loss recognition	(1,980)	(898)
DAC and VOBA related to noncredit OTTI losses recognized in accumulated other comprehensive income (loss)	1	6
DAC and VOBA	(1,881)	(1,190)
Policyholder dividend obligation	(2,986)	(1,771)
Subtotal	(6,846)	(3,853)
Deferred income tax benefit (expense) related to noncredit OTTI losses recognized in accumulated other comprehensive income (loss)	39	73
Deferred income tax benefit (expense)	(7,826)	(4,956)
Net unrealized investment gains (losses)	14,382	8,410
Net unrealized investment gains (losses) attributable to noncontrolling interests	3	4
Net unrealized investment gains (losses) attributable to MetLife, Inc.	$ 14,385	$ 8,414