CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Securities pledged as collateral	$ 1,700,000,000	$ 2,800,000,000
Preferred stock, par value	$ 0.01	$ 0.01	[1]
Preferred stock, shares authorized	100,000,000	100,000,000	[1]
Preferred stock, shares issued	0	0	[1]
Preferred stock, shares outstanding	0	0	[1]
Common stock, par value	$ 0.01	$ 0.01	[1]
Common stock, shares authorized	1,500,000,000	1,500,000,000	[1]
Common stock, shares issued	1,027,505,028	1,027,467,089	[1]
Common stock, shares outstanding	1,027,505,028	1,027,467,089	[1]
Securitized Loans Held for Investment [Member] | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure [Member]
Allowance for loan losses	11,264,000	13,938,000	[1]
Repurchase Agreements [Member] | Agency RMBS [Member]
Securities pledged as collateral	1,700,000,000	2,800,000,000	[1]
Securitized Loans [Member] | Non-Agency RMBS [Member] | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure [Member]
Securities pledged as collateral	3,200,000,000	3,300,000,000	[1]
Securitized Loans [Member] | Securitized Loans Held for Investment [Member] | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure [Member]
Securities pledged as collateral	$ 1,200,000,000	$ 238,000,000	[1]

[1] Derived from the audited consolidated financial statements.