CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014	[1]
Cash pledged as collateral		$ 2,098,919	$ 1,584,701
Agency debentures, pledged assets		97,463	1,368,350
Credit risk transfer securities, pledged assets		101,908	0
Commercial real estate debt investments, pledged assets		2,881,659	0
Commercial real estate debt and preferred equity, held for investment, pledged assets	[2]	220,390	0
Receivable for investment advisory income, from affiliates		$ 3,992	$ 10,402
Common Stock, par value		$ 0.01	$ 0.01
Common Stock, shares authorized		1,956,937,500	1,956,937,500
Common Stock, shares issued		947,826,176	947,643,079
Common Stock, shares outstanding		947,826,176	947,643,079
Senior Secured mortgages of Consolidated VIE, carrying value		$ 314,900	$ 398,600
Subordinated Secured mortgages of Consolidated VIE, fair value		2,600,000	0
Commercial real estate debt and preferred equity, held for investment, allowance for losses		0	0
Securitized debt of a consolidated VIE		2,377,067	0
Non-Agency mortgage-backed securities [Member]
Mortgage-backed securities, pledged assets		$ 332,034	$ 0
7.875% Series A Cumulative Redeemable Preferred Stock
Preferred Stock, shares authorized		7,412,500	7,412,500
Preferred Stock, shares issued		7,412,500	7,412,500
Preferred Stock, shares outstanding		7,412,500	7,412,500
7.625% Series C Cumulative Redeemable Preferred Stock
Preferred Stock, shares authorized		12,650,000	12,650,000
Preferred Stock, shares issued		12,000,000	12,000,000
Preferred Stock, shares outstanding		12,000,000	12,000,000
7.50% Series D Cumulative Redeemable Preferred Stock
Preferred Stock, shares authorized		18,400,000	18,400,000
Preferred Stock, shares issued		18,400,000	18,400,000
Preferred Stock, shares outstanding		18,400,000	18,400,000
Agency Mortgage Backed Securities
Mortgage-backed securities, pledged assets		$ 59,721,331	$ 74,006,480

[1] Derived from the audited consolidated financial statements at December 31, 2014.

[2] Includes senior securitized commercial mortgage loans of consolidated VIEs carried at fair value of $2.6 billion and $0 at September 30, 2015 and December 31, 2014, respectively.