CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands		Sep. 30, 2017		Dec. 31, 2016
Cash pledged as collateral		$ 689,290	[1]	$ 1,428,475	[2]
Credit risk transfer securities, pledged assets		251,077	[1]	608,707	[2]
Residential mortgage loans, pledged assets		723,705	[1]	314,746	[2]
Mortgage servicing rights, pledged assets		2,693	[1]	5,464	[2]
Commercial real estate debt investments, pledged assets		3,866,629	[1]	4,321,739	[2]
Commercial real estate debt and preferred equity, held for investment, pledged assets		482,822	[1]	506,997	[2]
Corporate debt, pledged assets		$ 432,460	[1]	$ 592,871	[2]
Common Stock, par value		$ 0.01	[1]	$ 0.01	[2]
Common Stock, shares authorized		1,917,837,500	[1]	1,945,437,500	[2]
Common Stock, shares issued		1,088,083,794	[1]	1,018,913,249	[2]
Common Stock, shares outstanding		1,088,083,794	[1]	1,018,913,249	[2]
Mortgage-backed securities, including pledged assets		$ 87,699,304		$ 77,715,902
Residential mortgage loans	[3]	895,919	[1]	342,289	[2]
Senior Secured mortgages of Consolidated VIE, fair value		3,600,000	[1]	3,900,000	[2]
Cash of Consolidated VIE	[4]	867,840	[1]	1,539,746	[2]
Securitized debt of a consolidated VIE		3,357,929	[1]	3,655,802	[2]
Agency Mortgage-backed Securities
Mortgage-backed securities, pledged assets		74,711,243	[1]	70,796,872	[2]
Mortgage-backed securities, including pledged assets		85,889,131	[1]	75,589,873	[2]
Non-Agency Mortgage-backed Securities
Mortgage-backed securities, pledged assets		670,425	[1]	1,064,603	[2]
Mortgage-backed securities, including pledged assets	[5]	1,227,235	[1]	1,401,307	[2]
Consolidated VIEs
Residential mortgage loans		139,800	[1]	165,900	[2]
Cash of Consolidated VIE		40,000	[1]	23,200	[2]
Consolidated VIEs | Non-Agency Mortgage-backed Securities
Mortgage-backed securities, including pledged assets		$ 72,100	[1]	$ 88,600	[2]
7.875% Series A Cumulative Redeemable Preferred Stock
Cumulative redeemable preferred stock, shares authorized		7,412,500	[1]	7,412,500	[2]
Cumulative redeemable preferred stock, shares issued		0	[1]	7,412,500	[2]
Cumulative redeemable preferred stock, shares outstanding		0	[1]	7,412,500	[2]
7.625% Series C Cumulative Redeemable Preferred Stock
Cumulative redeemable preferred stock, shares authorized		12,650,000	[1]	12,650,000	[2]
Cumulative redeemable preferred stock, shares issued		12,000,000	[1]	12,000,000	[2]
Cumulative redeemable preferred stock, shares outstanding		12,000,000	[1]	12,000,000	[2]
7.50% Series D Cumulative Redeemable Preferred Stock
Cumulative redeemable preferred stock, shares authorized		18,400,000	[1]	18,400,000	[2]
Cumulative redeemable preferred stock, shares issued		18,400,000	[1]	18,400,000	[2]
Cumulative redeemable preferred stock, shares outstanding		18,400,000	[1]	18,400,000	[2]
7.625% Series E Cumulative Redeemable Preferred Stock
Cumulative redeemable preferred stock, shares authorized		11,500,000	[1]	11,500,000	[2]
Cumulative redeemable preferred stock, shares issued		11,500,000	[1]	11,500,000	[2]
Cumulative redeemable preferred stock, shares outstanding		11,500,000	[1]	11,500,000	[2]
6.95% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Cumulative redeemable preferred stock, shares authorized		32,200,000	[1]	0	[2]
Cumulative redeemable preferred stock, shares issued		28,800,000	[1]	0	[2]
Cumulative redeemable preferred stock, shares outstanding		28,800,000	[1]	0	[2]

[1] As a result of a change to a clearing organization's rulebook effective January 3, 2017, beginning with the first quarter 2017 and in subsequent periods the Company is presenting the fair value of centrally cleared interest rate swaps net of variation margin pledged under such transactions. The variation margin was previously reported under cash and cash equivalents and is currently reported as a reduction to interest rate swaps, at fair value. Balances reported prior to the effective date will not be adjusted.

[2] Derived from the audited consolidated financial statements at December 31, 2016.

[3] Includes securitized residential mortgage loans of a consolidated VIE carried at fair value of $139.8 million and $165.9 million at September 30, 2017 and December 31, 2016, respectively.

[4] Includes cash of consolidated Variable Interest Entities ("VIEs") of $40.0 million and $23.2 million at September 30, 2017 and December 31, 2016, respectively.

[5] Includes $72.1 million and $88.6 million at September 30, 2017 and December 31, 2016, respectively, of non-Agency mortgage-backed securities in a consolidated VIE pledged as collateral and eliminated from the Company's Consolidated Statements of Financial Condition.