CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Cash pledged as collateral	$ 579,213	$ 1,428,475
Credit risk transfer securities, pledged assets	363,944	608,707
Residential mortgage loans, pledged assets	1,169,496	314,746
Mortgage servicing rights, pledged assets	5,224	5,464
Commercial real estate debt investments, pledged assets	3,070,993	4,321,739
Commercial real estate debt and preferred equity, held for investment, pledged assets	520,329	506,997
Corporate debt, pledged assets	$ 600,049	$ 592,871
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,929,300,000	1,945,437,500
Common stock, shares issued (in shares)	1,159,585,078	1,018,913,249
Common stock, shares outstanding (in shares)	1,159,585,078	1,018,913,249
7.875% Series A Cumulative Redeemable Preferred Stock
Preferred stock dividend rate, percentage	7.875%	7.875%
Cumulative redeemable preferred stock, shares authorized (in shares)	0	7,412,500
Cumulative redeemable preferred stock, shares issued (in shares)	0	7,412,500
Cumulative redeemable preferred stock, shares outstanding (in shares)	0	7,412,500
7.625% Series C Cumulative Redeemable Preferred Stock
Preferred stock dividend rate, percentage	7.625%	7.625%
Cumulative redeemable preferred stock, shares authorized (in shares)	12,000,000	12,650,000
Cumulative redeemable preferred stock, shares issued (in shares)	12,000,000	12,000,000
Cumulative redeemable preferred stock, shares outstanding (in shares)	12,000,000	12,000,000
7.50% Series D Cumulative Redeemable Preferred Stock
Preferred stock dividend rate, percentage	7.50%	7.50%
Cumulative redeemable preferred stock, shares authorized (in shares)	18,400,000	18,400,000
Cumulative redeemable preferred stock, shares issued (in shares)	18,400,000	18,400,000
Cumulative redeemable preferred stock, shares outstanding (in shares)	18,400,000	18,400,000
7.625% Series E Cumulative Redeemable Preferred Stock
Preferred stock dividend rate, percentage	7.625%	7.625%
Cumulative redeemable preferred stock, shares authorized (in shares)	11,500,000	11,500,000
Cumulative redeemable preferred stock, shares issued (in shares)	11,500,000	11,500,000
Cumulative redeemable preferred stock, shares outstanding (in shares)	11,500,000	11,500,000
6.95% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Preferred stock dividend rate, percentage	6.95%	6.95%
Cumulative redeemable preferred stock, shares authorized (in shares)	28,800,000	0
Cumulative redeemable preferred stock, shares issued (in shares)	28,800,000	0
Cumulative redeemable preferred stock, shares outstanding (in shares)	28,800,000	0
Non-Agency Mortgage-backed Securities
Mortgage-backed securities, pledged assets	$ 516,078	$ 1,064,603
Agency mortgage-backed securities, at fair value
Mortgage-backed securities, pledged assets	$ 83,628,132	$ 70,796,872

Pledged assets, mortgage servicing rights.

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Pledged assets not separately reported, commercial real estate debt and preferred equity, held for investment.

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Pledged assets not separately reported, commercial real estate debt investments.

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Carrying amount as of the balance sheet date of cash collateral held for borrowed securities, for which the cash is restricted as to withdrawal or usage.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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Face amount or stated value per share of common stock.

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The fair value, as of the date of each statement of financial position presented, of finance receivables which are owned but transferred to serve as collateral for the payment of the related debt obligation, and that are reclassified and separately reported in the statement of financial position.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The carrying amount as of the date of the latest financial statement presented of mortgage-related securities classified as available for sale or held for investment which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

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The percentage rate used to calculate dividend payments on preferred stock.

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