Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investments:
Amortized cost of fixed maturity securities available-for-sale	$ 333,599	$ 340,870
Fixed maturity securities relating to variable interest entities	350,187	374,266
Cost of equity securities available-for-sale	3,012	2,838
Actively traded securities	662	659
Fair value option and trading securities relating to variable interest entities	17,423	16,348
Mortgage loans:
Mortgage loans valuation allowances	322	347
Mortgage loans, at estimated fair value	57,703	56,592
Mortgage loans held-for-sale under fair value option	3	414
Policy loans	11,764	11,884
Real estate and real estate joint ventures relating to variable interest entities	10,712	9,918
Real estate held-for-sale	186	1
Other limited partnership interests relating to variable interest entities	7,401	6,688
Short-term Investments	13,955	16,906
Other invested assets relating to variable interest entities	16,229	21,145
Cash and cash equivalents relating to variable interest entities	7,585	15,738
Accrued investment income relating to variable interest entities	4,255	4,374
Premiums, reinsurance and other receivables relating to variable interest entities	21,859	21,634
Deferred policy acquisition costs and value of business acquired relating to variable interest entities	26,706	24,761
Other assets relating to variable interest entities	8,369	7,876
Separate account assets	317,201	235,393
Liabilities
Future policy benefits relating to variable interest entities	187,942	192,351
Policyholder account balances	212,885	225,821
Other policy-related balances relating to variable interest entities	15,214	15,463
Long-term debt at estimated fair value, relating to variable interest entities	18,653	19,062
Other liabilities relating to variable interest entities	23,168	22,492
Separate account liabilities	317,201	235,393
MetLife, Inc.'s stockholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	200,000,000	200,000,000
Preferred stock, shares issued	84,000,000	84,000,000
Preferred stock, shares outstanding	84,000,000	84,000,000
Preferred stock, aggregate liquidation preference	$ 2,100.00	$ 2,100.00
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000,000,000	3,000,000,000
Common stock, shares issued	1,125,224,024	1,094,880,623
Common stock, shares outstanding	1,122,030,137	1,091,686,736
Treasury stock, shares	3,193,887	3,193,887
Mortgage Loans Held-for-sale [Member]
Mortgage loans:
Mortgage loans held-for-sale under fair value option	0	49
Residential Mortgage Loans - FVO [Member]
Mortgage loans:
Mortgage loans, at estimated fair value	338	0
Variable interest entities [Member]
Investments:
Fixed maturity securities relating to variable interest entities	4,005	3,378
Fair value option and trading securities relating to variable interest entities	92	112
Mortgage loans:
Mortgage loans, at estimated fair value	1,621	2,715
Policy loans	2	0
Real estate and real estate joint ventures relating to variable interest entities	1,141	10
Other limited partnership interests relating to variable interest entities	53	274
Short-term Investments	8	0
Other invested assets relating to variable interest entities	78	81
Cash and cash equivalents relating to variable interest entities	70	99
Accrued investment income relating to variable interest entities	26	13
Premiums, reinsurance and other receivables relating to variable interest entities	22	5
Deferred policy acquisition costs and value of business acquired relating to variable interest entities	255	0
Other assets relating to variable interest entities	152	5
Separate account assets	1,033	0
Liabilities
Future policy benefits relating to variable interest entities	516	0
Policyholder account balances	56	0
Other policy-related balances relating to variable interest entities	123	0
Long-term debt at estimated fair value, relating to variable interest entities	1,868	2,527
Other liabilities relating to variable interest entities	88	40
Separate account liabilities	$ 1,033	$ 0