Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investments:
Amortized cost of fixed maturity securities available-for-sale	$ 338,871	$ 329,811
Fixed maturity securities relating to variable interest entities	366,339	350,271
Cost of equity securities available-for-sale	2,973	3,208
Actively traded securities	535	473
Trading and other securities relating to variable interest entities	18,328	18,268
Mortgage loans:
Valuation allowances for held-for-investment	361	481
Mortgage loans, at estimated fair value, relating to variable interest entities	57,201	56,915
Mortgage loans held-for-sale under fair value option	461	10,716
Real estate and real estate joint ventures relating to variable interest entities	8,477	8,563
Other limited partnership interests relating to variable interest entities	6,726	6,378
Other invested assets relating to variable interest entities	24,288	23,581
Cash and cash equivalents relating to variable interest entities	16,035	10,461
Accrued investment income relating to variable interest entities	4,404	4,344
Premiums, reinsurance and other receivables relating to variable interest entities	23,974	22,481
Other assets relating to variable interest entities	7,711	7,984
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	18,879	23,692
Other liabilities relating to variable interest entities	25,395	30,914
Other liabilities under fair value option	257	7,626
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	$ 2,100
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000,000,000	3,000,000,000
Common stock, shares issued	1,065,380,456	1,061,150,915
Common stock, shares outstanding	1,062,186,569	1,057,957,028
Treasury stock, shares	3,193,887	3,193,887
Variable interest entities
Investments:
Fixed maturity securities relating to variable interest entities	3,289	3,225
Trading and other securities relating to variable interest entities	166	280
Mortgage loans:
Mortgage loans, at estimated fair value, relating to variable interest entities	2,981	3,187
Real estate and real estate joint ventures relating to variable interest entities	10	15
Other limited partnership interests relating to variable interest entities	252	259
Other invested assets relating to variable interest entities	81	98
Cash and cash equivalents relating to variable interest entities	131	176
Accrued investment income relating to variable interest entities	14	16
Premiums, reinsurance and other receivables relating to variable interest entities	3	12
Other assets relating to variable interest entities	5	5
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	2,821	3,068
Other liabilities relating to variable interest entities	$ 54	$ 60