Chimera Investment (CIM) 10-K 20 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	CHIMERA INVESTMENT CORP
Trading Symbol	CIM
Entity Central Index Key	1,409,493
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		187,809,432
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,468,160,744

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and cash equivalents		$ 63,569	$ 177,714
Non-Agency RMBS, at fair value		2,851,316	3,330,063
Agency MBS, at fair value		4,364,828	4,167,754
Loans held for investment, at fair value		13,678,263	8,753,653
Accrued interest receivable		100,789	79,697
Other assets		114,391	166,350
Derivatives, at fair value, net		48,914	9,677
Total assets	[1]	21,222,070	16,684,908
Liabilities:
Repurchase agreements ($8.8 billion and $7.0 billion, pledged as collateral, respectively)		7,250,452	5,600,903
Securitized debt, collateralized by Non-Agency RMBS ($1.6 billion and $1.8 billion pledged as collateral, respectively)		205,780	334,124
Securitized debt at fair value, collateralized by loans held for investment ($13.3 billion and $8.8 billion pledged as collateral, respectively)		9,388,657	6,941,097
Payable for investments purchased		567,440	520,532
Accrued interest payable		61,888	48,670
Dividends payable		95,365	97,005
Accounts payable and other liabilities		17,191	16,694
Derivatives, at fair value		320	2,350
Total liabilities	[1]	17,587,093	13,561,375
Commitments and Contingencies (See Note 15)
Stockholders' Equity:
Common stock: par value $0.01 per share; 300,000,000 shares authorized, 187,809,288 and 187,739,634 shares issued and outstanding, respectively		1,878	1,877
Additional paid-in-capital		3,826,691	3,508,779
Accumulated other comprehensive income		796,902	718,106
Cumulative earnings		2,967,852	2,443,184
Cumulative distributions to stockholders		(3,958,534)	(3,548,471)
Total stockholders' equity		3,634,977	3,123,533
Total liabilities and stockholders' equity		21,222,070	16,684,908
Preferred Class A
Stockholders' Equity:
Preferred Stock, par value of $0.01 per share, 100,000,000 shares authorized:		58	58
Preferred Class B
Stockholders' Equity:
Preferred Stock, par value of $0.01 per share, 100,000,000 shares authorized:		$ 130	$ 0
[1]	The Company's consolidated statements of financial condition include assets of consolidated variable interest entities (“VIEs”) that can only be used to settle obligations and liabilities of the VIE for which creditors do not have recourse to the primary beneficiary (Chimera Investment Corporation). As of December 31, 2017 and December 31, 2016, total assets of consolidated VIEs were $14,987,464 and $10,761,954, respectively, and total liabilities of consolidated VIEs were $9,631,820 and $7,302,905, respectively. See Note 8 for further discussion.

CONSOLIDATED STATEMENTS OF FIN3

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Preferred Stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized (shares)	100,000,000	100,000,000
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	300,000,000	300,000,000
Common stock, shares issued (shares)	187,809,288	187,739,634
Common stock, shares outstanding (shares)	187,809,288	187,739,634
Repurchase Agreements | Residential Mortgage-Backed Securities
Securities pledged as collateral	$ 8,788,680,000	$ 7,033,866,000
Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Assets	14,987,464,000	10,761,954,000
Liabilities	9,631,820,000	7,302,905,000
Securitized Loans | Non-agency MBS
Securities pledged as collateral	1,600,000,000	1,800,000,000
Securitized Loans | Loans Held for Investment at Fair Value
Securities pledged as collateral	$ 13,300,000,000	$ 8,800,000,000
Preferred Class A
Preferred Stock, dividend rate (percent)	8.00%	8.00%
Preferred Stock, shares issued (shares)	5,800,000	5,800,000
Preferred Stock, shares outstanding (shares)	5,800,000	5,800,000
Preferred Stock, liquidation preference	$ 145,000	$ 145,000
Preferred Class B
Preferred Stock, dividend rate (percent)	8.00%
Preferred Stock, shares issued (shares)	13,000,000
Preferred Stock, shares outstanding (shares)	0
Preferred Stock, liquidation preference	$ 325,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net interest income:
Interest income	[1]	$ 1,138,758	$ 934,068	$ 872,737
Interest expense	[2]	532,748	347,857	259,365
Net interest income		606,010	586,211	613,372
Other-than-temporary impairments:
Total other-than-temporary impairment losses		(5,169)	(9,589)	(8,700)
Portion of loss recognized in other comprehensive income		(56,687)	(48,398)	(58,744)
Net other-than-temporary credit impairment losses		(61,856)	(57,987)	(67,444)
Other investment gains (losses):
Net unrealized gains (losses) on derivatives		47,976	50,093	67,385
Realized gains (losses) on terminations of interest rate swaps		(16,143)	(60,616)	(98,949)
Net realized gains (losses) on derivatives		(25,645)	(44,886)	(83,073)
Net gains (losses) on derivatives		6,188	(55,409)	(114,637)
Net unrealized gains (losses) on financial instruments at fair value		111,410	59,552	(158,433)
Net realized gains (losses) on sales of investments		9,123	18,155	77,074
Gain (loss) on deconsolidation		0	0	(256)
Gains (losses) on extinguishment of debt		(35,274)	(477)	(5,930)
Total other gains (losses)		91,447	21,821	(202,182)
Other income:
Other income		0	95,000	0
Total other income		0	95,000	0
Other expenses:
Management fees (net of recoveries)		0	0	17,703
Compensation and benefits		30,212	26,901	10,544
General and administrative expenses		17,650	17,516	31,633
Servicing fees		41,690	31,178	25,244
Deal expenses		21,273	17,424	8,272
Total other expenses		110,825	93,019	93,396
Income (loss) before income taxes		524,776	552,026	250,350
Income taxes		108	83	1
Net income (loss)		524,668	551,943	250,349
Dividend on preferred stock		33,484	2,449	0
Net income (loss) available to common shareholders		$ 491,184	$ 549,494	$ 250,349
Net income (loss) per share available to common shareholders:
Basic (usd per share)		$ 2.62	$ 2.93	$ 1.25
Diluted (usd per share)		$ 2.61	$ 2.92	$ 1.25
Weighted average number of common shares outstanding:
Basic (shares)		187,780,355	187,728,634	199,563,196
Diluted (shares)		188,287,320	188,024,838	199,650,177
Dividends declared per share of common stock (usd per share)		$ 2	$ 2.44	$ 1.92
[1]	Includes interest income of consolidated VIEs of $914,022, $678,623 and $575,715 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 8 to consolidated financial statements for further discussion.
[2]	Includes interest expense of consolidated VIEs of $390,858, $249,708 and $191,922 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 8 to consolidated financial statements for further discussion.

CONSOLIDATED STATEMENTS OF OPE5

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - Non Agency Residential Mortgage Backed Securities And Securitized Loans - Variable Interest Entities, Primary Beneficiary - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income, assets of consolidated VIEs	$ 914,022	$ 678,623	$ 575,715
Interest expense, non-recourse liabilities of VIEs	$ 390,858	$ 249,708	$ 191,922

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Comprehensive income (loss):
Net income (loss)	$ 524,668	$ 551,943	$ 250,349
Other comprehensive income:
Unrealized gains (losses) on available-for-sale securities, net	24,218	(88,527)	(263,049)
Reclassification adjustment for net losses included in net income for other-than-temporary credit impairment losses	61,856	57,987	67,444
Reclassification adjustment for net realized losses (gains) included in net income	(7,278)	(25,145)	(77,284)
Other comprehensive income (loss)	78,796	(55,685)	(272,889)
Comprehensive income (loss) before preferred stock dividends	603,464	496,258	(22,540)
Dividends on preferred stock	33,484	2,449	0
Comprehensive income (loss) available to common stock shareholders	$ 569,980	$ 493,809	$ (22,540)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands		Total	Common Stock Par Value	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Cumulative Earnings	Cumulative Distributions to Stockholders	Series A Preferred Stock Par Value	Series A Preferred Stock Par ValuePreferred Stock	Series B Preferred Stock Par Value	Series B Preferred Stock Par ValuePreferred Stock
Beginning Balance at Dec. 31, 2014		$ 3,607,690	$ 2,055	$ 3,614,409	$ 1,046,680	$ 1,653,029	$ (2,708,483)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		250,349				250,349
Cumulative effect of accounting change	[1]	(12,137)				(12,137)
Other comprehensive income (loss)		(272,889)			(272,889)
Stock based compensation		1,979	2	1,977
Repurchase of common stock		(250,000)	(180)	(249,820)
Common dividends declared		(378,804)					(378,804)
Preferred dividends declared		0
Ending Balance at Dec. 31, 2015		2,946,188	1,877	3,366,566	773,791	1,891,241	(3,087,287)		$ 0		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		551,943				551,943
Other comprehensive income (loss)		(55,685)			(55,685)
Stock based compensation		2,206		2,206
Common dividends declared		(458,735)					(458,735)
Preferred dividends declared		(2,449)					(2,449)
Issuance of preferred stock		140,065		140,007					58
Ending Balance at Dec. 31, 2016		3,123,533	1,877	3,508,779	718,106	2,443,184	(3,548,471)		58		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		524,668				524,668
Other comprehensive income (loss)		78,796			78,796
Stock based compensation		3,614	1	3,613
Common dividends declared		(376,579)					(376,579)
Preferred dividends declared		(33,484)					(33,484)	$ (12,000)		$ (22,000)
Issuance of preferred stock		314,429		314,299							130
Ending Balance at Dec. 31, 2017		$ 3,634,977	$ 1,878	$ 3,826,691	$ 796,902	$ 2,967,852	$ (3,958,534)		$ 58		$ 130
[1]	Adoption of ASU No. 2014-13, Measuring the Financial Assets and the Financial Liabilities of a Consolidated Collateralized Financing Entity.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Cash Flows From Operating Activities:
Net income	$ 524,668	$ 551,943	$ 250,349
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
(Accretion) amortization of investment discounts/premiums, net	(25,422)	(3,127)	3,813
Accretion (amortization) of deferred financing costs and securitized debt discounts/premiums, net	7,395	1,543	17,145
Amortization of swaption premium	6,269	6,559	0
Net unrealized losses (gains) on derivatives	(47,976)	(50,093)	(67,385)
Proceeds (payments) for derivative sales and settlements	0	0	(13,495)
Margin (paid) received on derivatives	31,442	56,050	82,671
Net unrealized losses (gains) on financial instruments at fair value	(111,410)	(59,552)	158,433
Net realized losses (gains) on sales of investments	(9,123)	(18,155)	(77,074)
(Gains) loss on deconsolidation	0	0	256
Net other-than-temporary credit impairment losses	61,856	57,987	67,444
(Gain) loss on extinguishment of debt	35,274	477	5,930
Equity-based compensation expense	3,614	2,204	1,979
Changes in operating assets:
Decrease (increase) in accrued interest receivable, net	(21,091)	(13,450)	4,852
Decrease (increase) in other assets	18,080	3,994	(42,738)
Changes in operating liabilities:
Increase (decrease) in accounts payable and other liabilities	498	5,290	8,935
Increase (decrease) in investment management fees and expenses payable to affiliate	0	0	(10,357)
Increase (decrease) in accrued interest payable, net	13,217	11,237	5,544
Net cash provided by (used in) operating activities	487,291	552,907	396,302
Cash Flows From Investing Activities:
Acquisition of investments in consolidated VIEs	(398,261)	0	(109,872)
Disposition of investments in consolidated VIEs	0	0	2,601
Net cash provided by (used in) investing activities	(4,331,009)	(1,270,560)	2,037,911
Cash Flows From Financing Activities:
Proceeds from repurchase agreements	44,120,574	34,202,707	41,644,280
Payments on repurchase agreements	(42,471,025)	(36,041,143)	(42,660,323)
Net proceeds from preferred stock offerings	314,429	140,065	0
Payments on repurchase of common stock	0	0	(250,000)
Proceeds from securitized debt borrowings, collateralized by loans held for investment	5,152,469	4,797,255	1,483,301
Payments on securitized debt borrowings, collateralized by loans held for investment	(2,844,132)	(1,668,670)	(2,138,623)
Payments on securitized debt borrowings, collateralized by Non-Agency RMBS	(131,039)	(194,634)	(182,217)
Common dividends paid	(375,771)	(454,275)	(381,189)
Preferred dividends paid	(35,932)	0	0
Net cash provided by (used in) financing activities	3,729,573	781,305	(2,484,771)
Net increase (decrease) in cash and cash equivalents	(114,145)	63,652	(50,558)
Cash and cash equivalents at beginning of period	177,714	114,062	164,620
Cash and cash equivalents at end of period	63,569	177,714	114,062
Supplemental disclosure of cash flow information:
Interest received	1,092,245	917,491	881,403
Interest paid	512,133	335,077	236,676
Management fees and expenses paid	0	0	34,996
Non-cash investing activities:
Payable for investments purchased	567,440	520,532	560,641
Net change in unrealized gain (loss) on available-for sale securities	78,796	(55,685)	(272,889)
Acquisition of securities in Consolidated VIEs
Securitized loans held for investment, at fair value	419,222	0	295,225
Securitized debt at fair value	(20,961)	0	(185,353)
Non-cash financing activities:
Common dividends declared, not yet paid	95,365	94,557	90,097
Dividends on preferred stock	0	2,449	0
Agency MBS portfolio
Cash Flows From Investing Activities:
Purchases	(1,326,178)	(1,040,290)	(6,590,731)
Sales	743,937	2,570,025	7,563,771
Principal payments	423,506	649,961	1,061,193
Non-agency MBS
Cash Flows From Investing Activities:
Purchases	(15,262)	(203,400)	(850,750)
Sales	5,045	95,399	158,404
Principal payments	568,339	532,701	385,988
Loans held for investment:
Cash Flows From Investing Activities:
Purchases	(6,120,543)	(4,897,370)	(281,811)
Principal payments	1,788,408	1,022,414	699,118
Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Disposition of securities in Consolidated VIEs
Non-agency RMBS, at fair value	0	0	49,118
Securitized loans held for investment, at fair value	0	0	(287,806)
Securitized debt at fair value	$ 0	$ 0	$ 236,087

Organization

Organization	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Chimera Investment Corporation (the “Company”) was organized in Maryland on June 1, 2007. The Company commenced operations on November 21, 2007 when it completed its initial public offering. The Company elected to be taxed as a real estate investment trust (“REIT”) under the Internal Revenue Code of 1986, as amended, and regulations promulgated thereunder (the “Code”). The Company conducts its operations through various subsidiaries including subsidiaries it treats as taxable REIT subsidiaries (“TRS”). In general, a TRS may hold assets and engage in activities that the Company cannot hold or engage in directly and generally may engage in any real estate or non-real estate related business. The Company currently has eight wholly owned direct subsidiaries: Chimera RMBS Whole Pool LLC, and Chimera RMBS LLC formed in June 2009; CIM Trading Company LLC (“CIM Trading”), formed in July 2010; Chimera Funding TRS LLC (“CIM Funding TRS”), a TRS formed in October 2013, Chimera CMBS Whole Pool LLC and Chimera RMBS Securities LLC formed in March 2015; Chimera Insurance Company, LLC formed in July 2015 and Chimera RR Holdings LLC formed in April 2016.

Summary of the Significant Acco

Summary of the Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of the Significant Accounting Policies	Summary of the Significant Accounting Policies (a) Basis of Presentation and Consolidation The accompanying consolidated financial statements and related notes of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). In the opinion of management, all adjustments considered necessary for a fair presentation of the Company's financial position, results of operations and cash flows have been included. Certain prior period amounts have been reclassified to conform to the current period's presentation. The consolidated financial statements include, the Company’s accounts, the accounts of its wholly-owned subsidiaries, and variable interest entities (“VIEs”) in which the Company is the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation. The Company uses securitization trusts considered to be VIEs in its securitization and re-securitization transactions. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest, or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary, and is generally the entity with (i) the power to direct the activities that most significantly impact the VIEs’ economic performance, and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. For VIEs that do not have substantial on-going activities, the power to direct the activities that most significantly impact the VIEs’ economic performance may be determined by an entity’s involvement with the design and structure of the VIE. The trusts are structured as pass through entities that receive principal and interest on the underlying collateral and distribute those payments to the security holders. The assets held by the securitization entities are restricted in that they can only be used to fulfill the obligations of the securitization entity. The Company’s risks associated with its involvement with these VIEs are limited to its risks and rights as a holder of the security it has retained. Determining the primary beneficiary of a VIE requires judgment. The Company determined that for the securitizations it consolidates, its ownership provides the Company with the obligation to absorb losses or the right to receive benefits from the VIE that could be significant to the VIE. In addition, the Company has the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance (“power”) such as rights to direct servicer activity or the Company was determined to have power in connection with its involvement with the structure and design of the VIE. The Company’s interest in the assets held by these securitization vehicles, which are consolidated on the Company’s Statements of Financial Condition, is restricted by the structural provisions of these trusts, and a recovery of the Company’s investment in the vehicles will be limited by each entity’s distribution provisions. The liabilities of the securitization vehicles, which are also consolidated on the Company’s Statements of Financial Condition, are non-recourse to the Company, and can only be satisfied from each securitization vehicle’s respective asset pool. The assets of securitization entities are comprised of residential mortgage backed securities (“RMBS”) or residential mortgage loans. See Notes 3, 4 and 8 for further discussion of the characteristics of the securities and loans in the Company’s portfolio. (b) Statements of Financial Condition Presentation The Company’s Consolidated Statements of Financial Condition include both the Company’s direct assets and liabilities and the assets and liabilities of consolidated securitization vehicles. Assets of each consolidated VIE can only be used to satisfy the obligations of that VIE, and the liabilities of consolidated VIEs are non-recourse to the Company. The Company is not obligated to provide, nor does it intend to provide, any financial support to these consolidated securitization vehicles. The notes to the consolidated financial statements describe the Company’s assets and liabilities including the assets and liabilities of consolidated securitization vehicles. See Note 8 for additional information related to the Company’s investments in consolidated securitization vehicles. (c) Cash and Cash Equivalents Cash and cash equivalents include cash on hand and cash deposited overnight in money market funds, which are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation. There were no restrictions on cash and cash equivalents at December 31, 2017 and December 31, 2016 . (d) Agency and Non-Agency Mortgage-Backed Securities The Company invests in mortgage backed securities (“MBS”) representing interests in obligations backed by pools of mortgage loans. The Company delineates between Agency MBS and Non-Agency MBS as follows: (1) Agency MBS are mortgage pass-through certificates, collateralized mortgage obligations (“CMOs”), and other MBS representing interests in or obligations backed by pools of mortgage loans issued or guaranteed by agencies of the U.S. Government, such as Ginnie Mae, or federally chartered corporations such as Freddie Mac or Fannie Mae where principal and interest repayments are guaranteed by the respective agency of the U.S. Government or federally chartered corporation; and (2) Non-Agency MBS are not issued or guaranteed by a U.S. Government Agency or other institution and are subject to credit risk. Repayment of principal and interest on Non-Agency MBS is subject to the performance of the mortgage loans or MBS collateralizing the obligation. The Company also invests in Interest Only Agency MBS strips and Interest Only Non-Agency RMBS strips (“IO MBS strips”). IO MBS strips represent the Company’s right to receive a specified proportion of the contractual interest flows of the collateral. Interest income on IO MBS strips is accrued based on the outstanding notional balance and the security’s contractual terms, and amortization of any premium is calculated in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 325-40, Beneficial Interests in Securitized Financial Assets (“ASC 325-40”). The Company accounts for IO MBS strips at fair value with changes in fair value recognized in the Company’s Consolidated Statements of Operations. The Company classifies the majority of its MBS as available-for-sale and records investments at estimated fair value as described in Note 5 of these consolidated financial statements. The Company includes unrealized gains and losses considered to be temporary on certain MBS in Other comprehensive income (“OCI”) in the Consolidated Statements of Operations. For IO MBS strips and certain other MBS investments, the Company carries these investments at fair value with changes in fair value included in earnings in the Consolidated Statements of Operations. From time to time, as part of the overall management of its portfolio, the Company may sell any of its investments and recognize a realized gain or loss as a component of earnings in the Consolidated Statements of Operations utilizing the average cost method. The Company’s accounting policy for interest income and impairment related to its MBS is as follows: Interest Income Recognition The recognition of interest income on MBS securities varies depending on the characteristics of the security as follows: Agency MBS and Non-Agency RMBS of High Credit Quality FASB ASC 310-20, Nonrefundable Fees and Other Costs (“ASC 310-20”) is applied to the recognition of interest income for the following securities: • Certain Agency MBS • Non-Agency RMBS that meet all of the following conditions at the acquisition date (referred to hereafter as “Non-Agency RMBS of High Credit Quality”): 1. Rated AA or higher by a nationally recognized credit rating agency using the lowest rating available; 2. The Company expects to collect all of the security's contractual cash flows; and 3. The security cannot be contractually prepaid such that the Company would not recover substantially all of its recorded investment. Under ASC 310-20, interest income, including premiums and discounts associated with the acquisition of these securities, is recognized over the life of such securities using the interest method based on the contractual cash flows of the security. In applying the interest method, the Company considers estimates of future principal prepayments in the calculation of the effective yield. Differences that arise between previously anticipated prepayments and actual prepayments received, as well as changes in future prepayment assumptions, result in a recalculation of the effective yield on the security. This recalculation of the effective yield is updated on a quarterly basis. Upon a recalculation of the effective yield, the investment in the security is adjusted to the amount that would have existed had the new effective yield been retrospectively applied since acquisition with a corresponding charge or credit to interest income. Non-Agency RMBS Not of High Credit Quality Non-Agency RMBS purchased at a discount and not of high credit quality at the time of purchase are accounted for under ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality (“ASC 310-30”) or ASC 325-40 (referred to hereafter as “Non-Agency RMBS Not of High Credit Quality”). Non-Agency RMBS are accounted for under ASC 310-30 if the following conditions are met as of the acquisition date: 1. There is evidence of deterioration in credit quality of the security from its inception; and 2. It is probable that the Company will be unable to collect all contractual cash flows of the security. Non-Agency RMBS that are not within the scope of ASC 310-30 are accounted for under ASC 325-40 if at the acquisition date: 1. The security is not of high credit quality (defined as rated below AA or is unrated), or 2. The security can contractually be prepaid or otherwise settled in such a way that the Company would not recover substantially all of its recorded investment. Interest income on Non-Agency RMBS Not of High Credit Quality is recognized using the interest method based on management’s estimates of cash flows expected to be collected. The effective interest rate on these securities is based on management’s estimate for each security of the projected cash flows, which are estimated based on observation of current market information and include assumptions related to fluctuations in prepayment speeds and the timing and amount of credit losses. On a quarterly basis, the Company reviews and, if appropriate, makes adjustments to its cash flow projections based on inputs and analyses received from external sources, internal models, and the Company’s judgments about prepayment rates, the timing and amount of credit losses, and other factors. Changes in the amount or timing of cash flows from those originally projected, or from those estimated at the last evaluation date, are considered to be either positive changes or adverse changes. For securities accounted for under ASC 325-40, any positive or adverse change in cash flows that does not result in the recognition of an other-than-temporary impairment (“OTTI”) results in a retrospective increase or decrease in the effective interest rate used to recognize interest income. For securities accounted for under ASC 310-30, only significant positive changes are reflected prospectively in the effective interest rate used to recognize interest income. Under ASC 310-30, adverse changes in cash flows expected to be collected for Non-Agency RMBS, in an unrealized loss position, generally result in recognition of an OTTI with no change in the effective interest rate used to recognize interest income. Impairment Considerations Applicable to certain MBS When the fair value of an available-for-sale MBS is less than its amortized cost, the security is considered impaired. On a quarterly basis, the Company evaluates its securities for OTTI. If the Company intends to sell an impaired security, or it is more-likely-than-not that the Company will be required to sell an impaired security before its anticipated recovery, then the Company must recognize an OTTI through a charge to earnings equal to the entire difference between the investment’s amortized cost and its fair value at the measurement date. If the Company does not intend to sell an impaired security and it is not more-likely-than-not that it would be required to sell an impaired security before recovery, the Company must further evaluate the security for impairment due to credit losses. The credit component of OTTI is recognized in earnings and the remaining component is recorded as a component of OCI. Following the recognition of an OTTI through earnings, a new amortized cost basis is established for the security and subsequent recovery in fair value may not be adjusted through current earnings. Subsequent recoveries are amortized into income over the remaining life of the security as an adjustment to yield. When evaluating whether the Company intends to sell an impaired security or will more-likely-than-not be required to sell an impaired security before recovery, the Company makes judgments that consider among other things, its liquidity, leverage, contractual obligations, and targeted investment strategy to determine its intent and ability to hold the investments that are deemed impaired. The determination as to whether an OTTI exists is based on factual information available at the time of assessment as well as the Company’s estimates of future conditions. As a result, the determination of OTTI and its timing and amount is based on estimates that may change materially over time. The Company’s estimate of the amount and timing of cash flows for its MBS is based on its review of the underlying securities or mortgage loans securing the MBS. The Company considers historical information available and expected future performance of the underlying securities or mortgage loans, including timing of expected future cash flows, prepayment rates, default rates, loss severities, delinquency rates, percentage of non-performing loans, extent of credit support available, Fair Isaac Corporation (“FICO”) scores at loan origination, year of origination, loan-to-value ratios, geographic concentrations, as well as reports by credit rating agencies, current and forecast interest rates, general market assessments and dialogue with market participants. As a result, substantial judgment is used in the Company’s analysis to determine the expected cash flows for its MBS. Considerations Applicable to Non-Agency RMBS of High Credit Quality The impairment assessment for Non-Agency RMBS of High Credit Quality involves comparing the present value of the remaining cash flows expected to be collected to the amortized cost of the security at the assessment date. The discount rate used to calculate the present value of the expected future cash flows is based on the security’s effective interest rate as calculated under ASC 310-20 (i.e., the discount rate implicit in the security as of the last measurement date). If the present value of the remaining cash flows expected to be collected is less than the amortized cost basis, an OTTI is recognized in earnings for the difference. This amount is considered to be the credit loss component; the remaining difference between amortized cost and the fair value of the security is considered to be the portion of loss recognized in other comprehensive income. Considerations Applicable to Non-Agency RMBS Not of High Credit Quality Non-Agency RMBS within the scope of ASC 325-40 or ASC 310-30 are considered other-than-temporarily impaired when the following two conditions exist: (1) the fair value is less than the amortized cost basis, and (2) there has been an adverse change in cash flows expected to be collected from the last measurement date (i.e. adverse changes in either the amount or timing of cash flows from those previously expected). The OTTI is separated into a credit loss component that is recognized in earnings and the portion of loss recognized in other comprehensive income. The credit component is comprised of the impact of the fair value decline due to changes in assumptions related to default (collection) risk and prepayments. The portion of loss recognized in other comprehensive income comprises the change in fair value of the security due to all other factors, including changes in benchmark interest rates and market liquidity. In determining the OTTI related to credit losses for securities, the Company compares the present value of the remaining cash flows adjusted for prepayments expected to be collected at the current financial reporting date to the present value of the remaining cash flows expected to be collected at the original purchase date (or the last date those estimates were revised for accounting purposes). The discount rate used to calculate the present value of expected future cash flows is the effective interest rate used for income recognition purposes as determined under ASC 325-40 or ASC 310-30. The determination of whether an OTTI exists and, if so, the extent of the credit component is subject to significant judgment and management’s estimates of both historical information available at the time of assessment, the current market environment, as well as the Company’s estimates of the future performance and projected amount and timing of cash flows expected to be collected on the security. As a result, the timing and amount of OTTI constitutes an accounting estimate that may change materially over time. Investments for which the Company has elected the fair value option are not evaluated for OTTI as all changes in fair value are reflected in earnings. (e) Loans Held for Investment The Company's loans held for investment portfolio is comprised of seasoned residential mortgage loans that are not guaranteed as to repayment of principal or interest. These loans are serviced and may be modified by a third-party servicer. The Company generally has the ability to approve certain loan modifications and determine the course of action to be taken as it relates to certain loans in default, including whether or not to proceed with foreclosure. Additionally, in certain cases, the Company has the ability to remove the servicer with or without cause upon prior notice. These mortgage loans are designated as held for investment. Interest income on loans held for investment is recognized over the expected life of the loans using the interest method with changes in yield reflected in earnings on a prospective basis and are carried at fair value with changes in fair value recorded in earnings. The Company estimates the fair value of securitized loans as described in Note 5 of these consolidated financial statements. Interest is accrued on all loans held for investment when due. Interest which is not received at the due date is written off when it becomes delinquent. Nonrefundable fees and costs related to acquiring the Company’s residential mortgage loans are recognized as expenses in the Consolidated Statements of Operations. Income recognition is suspended for loans when, based on information from the servicer, a full recovery of interest or principal becomes doubtful. Real estate owned Real estate owned (“REO”) represents properties which the Company has received the legal title of the property to satisfy the outstanding loan. REO is re-categorized from loan to REO when the Company takes legal title of the property. REO assets are measured and reported at the estimated fair value less the estimated cost to sell at the end of each reporting period. At the time the asset is re-categorized, any difference between the previously recorded loan balance and the carrying value of the REO at the time the Company takes legal title of the property, is recognized as a loss. All REO assets of the Company are held-for-sale and it is the Company’s intention to sell the property in the shortest time possible to maximize their return and recovery on the previously recorded loan. The carrying value of REO assets at December 31, 2017 and December 31, 2016 was $10 million and $13 million , respectively, and were recorded in Other Assets on the Company’s consolidated statements of financial condition. (f) Repurchase Agreements The Company finances the acquisition of a significant portion of its mortgage-backed securities with repurchase agreements. The Company has evaluated each agreement and has determined that each of the repurchase agreements be accounted for as secured borrowings, which is recourse to the Company. (g) Securitized Debt, collateralized by Non-Agency RMBS and Securitized Debt, collateralized by Loans held for investment Certain re-securitization transactions classified as Securitized Debt, collateralized by Non-Agency RMBS, reflect the transfer to a trust of fixed or adjustable rate MBS which are classified as Non-Agency RMBS that pay interest and principal to the debt holders of that re-securitization. Re-securitization transactions completed by the Company that did not qualify as sales are accounted for as secured borrowings. The associated securitized debt is carried at amortized cost, net of any unamortized premiums or discounts. Certain transactions involving residential mortgage loans are accounted for as secured borrowings, and are recorded as Securitized loans held for investment and the corresponding debt as Securitized debt, collateralized by loans held for investment in the Consolidated Statements of Financial Condition. These securitizations are collateralized by residential adjustable or fixed rate mortgage loans that have been placed in a trust and pay interest and principal to the debt holders of that securitization. The Securitized debt, collateralized by loans held for investment, is carried at fair value. The Company recognizes interest expense on securitized debt over the contractual life of the debt using the interest method with changes in yield reflected in earnings on a retrospective basis. The Company estimates the fair value of its securitized debt as described in Note 5 to these consolidated financial statements. (h) Fair Value Agency MBS: The Company has elected to account for Agency MBS investments acquired on or after July 1, 2017 under the fair value option. Under the fair value option, these investments will be carried at fair value, with changes in fair value reported in earnings (included as part of “Net unrealized gains (losses) on financial instruments at fair value”). Consistent with all other investments for which the Company has elected the fair value option, the Company will recognize revenue on a prospective basis in accordance with guidance in ASC 325-40. All Agency MBS investments owned prior to July 1, 2017 will continue to be carried at fair value with changes in fair value reported in other comprehensive income (OCI) as available-for-sale investments. All revenue recognition for these Agency MBS investments owned prior to July 1, 2017 will be in accordance with ASC 310-20, per the Company’s accounting practices. Non-Agency RMBS - Overcollateralization Class: The Company has elected the fair value option for certain interests in Non-Agency RMBS which it refers to as the overcollateralization classes. The cash flows for these holdings are generally subordinate to all other interests of the trusts and generally only pay out funds when certain ratios are met and excess cash holdings, as determined by the trustee, are available for distribution to the overcollateralization class. Many of the investments in this group have no current cash flows and may not ever pay cash flows, depending on the loss experience of the collateral group supporting the investment. Estimating future cash flows for this group of Non-Agency RMBS investments is highly subjective and uncertain; therefore, the Company records these holdings at fair value with changes in fair value reflected in earnings. Changes in fair value of the overcollateralization classes are presented in Net unrealized gains (losses) on financial instruments at fair value on the Consolidated Statements of Operations. The fair value of the Non-Agency RMBS carried at fair value with changes in fair value reflected in earnings was $14 million and $19 million as of December 31, 2017 and December 31, 2016 , respectively. Interest-Only MBS: The Company accounts for the IO MBS strips at fair value with changes in fair value reported in earnings. The IO MBS strips are included in MBS, at fair value, on the accompanying Consolidated Statements of Financial Condition. Included in Non-Agency RMBS, at fair value on the Consolidated Statements of Financial Condition are IO MBS strips carried at fair value with changes in fair value reflected in earnings of $219 million and $266 million as of December 31, 2017 and December 31, 2016 . Included in Agency MBS, at fair value on the Consolidated Statements of Financial Condition are IO MBS strips carried at fair value with changes in fair value reflected in earnings of $104 million and $145 million as of December 31, 2017 and December 31, 2016 . Interest income reported on all IO MBS securities was $31 million and $43 million for the years ended December 31, 2017 and 2016 , respectively. Loans Held for Investment: The Company’s Loans held for investment are carried at fair value with changes in fair value reflected in earnings. The Company carries Loans held for investment at fair value as it may resecuritize these loans in the future. Additionally, the fair value option allows both the loans and related financing to be consistently reported at fair value and to achieve operational and valuation simplifications. Changes in fair value of Loans held for investment are presented in Net unrealized gains (losses) on financial instruments at fair value on the Consolidated Statements of Operations. Securitized Debt, Collateralized by Loans Held for Investment: The Company’s securitized debt, collateralized by loans held for investment, is carried at fair value with changes in fair value reflected in earnings. The Company has elected the fair value option for these financings as it may call or restructure these debt financings in the future. Additionally, the fair value option allows both the loans and related financing to be consistently reported at fair value and to achieve operational and valuation simplifications. Changes in fair value of securitized debt, collateralized by loans held for investment are presented in Net unrealized gains (losses) on financial instruments at fair value on the Consolidated Statements of Operations. Fair Value Disclosure A complete discussion of the methodology utilized by the Company to estimate the fair value of its financial instruments is included in Note 5 to these consolidated financial statements. (i) Derivative Financial Instruments The Company’s investment policies permit it to enter into derivative contracts, including interest rate swaps, swaptions, mortgage options, futures, and interest rate caps to manage its interest rate risk and, from time to time, enhance investment returns. The Company’s derivatives are recorded as either assets or liabilities in the Consolidated Statements of Financial Condition and measured at fair value. These derivative financial instrument contracts are not designated as hedges for GAAP; therefore, all changes in fair value are recognized in earnings. The Company estimates the fair value of its derivative instruments as described in Note 5 of these consolidated financial statements. Net payments on derivative instruments are included in the Consolidated Statements of Cash Flows as a component of net income. Unrealized gains (losses) on derivatives are removed from net income to arrive at cash flows from operating activities. The Company elects to net the fair value of its derivative contracts by counterparty when appropriate. These contracts contain legally enforceable provisions that allow for netting or setting off of all individual derivative receivables and payables with each counterparty and therefore, the fair value of those derivative contracts are reported net by counterparty. The credit support annex provisions of the Company’s derivative contracts allow the parties to mitigate their credit risk by requiring the party which is in a net payable position to post collateral. As the Company elects to net by counterparty the fair value of derivative contracts, it also nets by counterparty any cash collateral exchanged as part of the derivative. Refer to Note 9 Derivative Instruments for further details. (j) Sales, Securitizations, and Re-Securitizations The Company periodically enters into transactions in which it sells financial assets, such as MBS and mortgage loans. Gains and losses on sales of assets are calculated using the average cost method whereby the Company records a gain or loss on the difference between the average amortized cost of the asset and the proceeds from the sale. In addition, the Company from time to time securitizes or re-securitizes assets and sells tranches in the newly securitized assets. These transactions may be recorded as either sales, whereby the assets contributed to the securitization are removed from the Consolidated Statements of Financial Condition and a gain or loss is recognized, or as secured borrowings whereby the assets contributed to the securitization are not derecognized but rather the debt issued by the securitization entity are recorded to reflect the term financing of the assets. In these securitizations and re-securitizations, the Company may retain senior or subordinated interests in the securitized or re-securitized assets. In transfers that are considered secured borrowings, no gain or loss is recognized. Any difference in the proceeds received and the carrying value of the transferred asset is recorded as a premium or discount and amortized into earnings as an adjustment to yield. (k) Income Taxes The Company has elected to be taxed as a REIT and intends to comply with the provision of the Code, with respect thereto. Accordingly, the Company will generally not be subject to federal, state or local income taxes to the extent that qualifying distributions are made to stockholders and as long as certain asset, income, distribution and stock ownership tests are met. If the Company failed to qualify as a REIT and did not qualify for certain statutory relief provisions, the Company would be subject to federal, state and local income taxes and may be precluded from qualifying as a REIT for the subsequent four taxable years following the year in which the REIT qualification was lost. The Company and CIM Funding TRS have made joint elections to treat CIM Funding TRS as a TRS. CIM Funding TRS is taxable as a domestic C corporation and subject to federal, state, and local income taxes based upon its taxable income. A tax position is recognized only when, based on management’s judgment regarding the application of income tax laws, it is more likely than not that the tax position will be sustained upon examination. The Company does not have any unrecognized tax positions that would affect its financial statements or require disclosure. No accruals for penalties and interest were necessary as of December 31, 2017 or 2016. (l) Net Income per Share The Company calculates basic net income per share by dividing net income for the period by the basic weighted-average shares of its common stock outstanding for that period. Diluted net income per share takes into account the effect of dilutive instruments such as unvested restricted stock. (m) Stock-Based Compensation Compensation expense for equity based awards granted to the Company’s independent directors and stock based compensation awards granted to employees of the Company subject only to service condition is recognized on a straight-line basis over the vesting period of such awards, based upon the fair value of such awards at the grant date. The Company recognizes forfeitures when they occur and does not adjust the fair value of the grants for estimated forfeitures. For awards subject to vesting on a straight line basis, the total amount of expense is at least equal to the measured expens

Mortgage-Backed Securities

Mortgage-Backed Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Mortgage-Backed Securities	Mortgage-Backed Securities The Company classifies its Non-Agency RMBS as senior, senior IO, subordinated, or subordinated IO. The Company also invests in residential, commercial and IO Agency MBS. Senior interests in Non-Agency RMBS are considered to be entitled to the first principal repayments in their pro-rata ownership interests at the acquisition date. The tables below present amortized cost, fair value and unrealized gain/losses of Company's MBS investments as of December 31, 2017 and December 31, 2016 . December 31, 2017 (dollars in thousands) Principal or Notional Value Total Premium Total Discount Amortized Cost Fair Value Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gain/(Loss) Non-Agency RMBS Senior $ 2,733,926 $ 540 $ (1,257,103 ) $ 1,477,363 $ 2,231,415 $ 754,234 $ (182 ) $ 754,052 Senior, interest-only 4,862,461 262,996 — 262,996 210,850 15,761 (67,907 ) (52,146 ) Subordinated 501,455 10,571 (177,206 ) 334,820 401,225 66,704 (299 ) 66,405 Subordinated, interest-only 201,378 7,369 — 7,369 7,826 902 (445 ) 457 Agency MBS Residential 2,227,128 123,245 — 2,350,373 2,322,180 5,706 (33,899 ) (28,193 ) Commercial 1,894,594 47,430 (4,685 ) 1,937,339 1,938,281 17,041 (16,099 ) 942 Interest-only 3,021,840 111,277 — 111,277 104,367 834 (7,744 ) (6,910 ) Total $ 15,442,782 $ 563,428 $ (1,438,994 ) $ 6,481,537 $ 7,216,144 $ 861,182 $ (126,575 ) $ 734,607 December 31, 2016 (dollars in thousands) Principal or Notional Value Total Premium Total Discount Amortized Cost Fair Value Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gain/(Loss) Non-Agency RMBS Senior $ 3,190,947 $ 231 $ (1,412,058 ) $ 1,779,120 $ 2,511,003 $ 732,133 $ (250 ) $ 731,883 Senior, interest-only 5,648,339 292,396 — 292,396 253,539 18,674 (57,531 ) (38,857 ) Subordinated 673,259 16,352 (212,734 ) 476,877 553,498 77,857 (1,236 ) 76,621 Subordinated, interest-only 266,927 13,878 — 13,878 12,024 — (1,854 ) (1,854 ) Agency MBS Residential 2,594,570 149,872 — 2,744,442 2,705,978 11,235 (49,699 ) (38,464 ) Commercial 1,331,543 37,782 (2,688 ) 1,366,637 1,316,975 175 (49,837 ) (49,662 ) Interest-only 3,356,491 152,175 — 152,175 144,800 1,893 (9,268 ) (7,375 ) Total $ 17,062,076 $ 662,686 $ (1,627,480 ) $ 6,825,525 $ 7,497,817 $ 841,967 $ (169,675 ) $ 672,292 The table below presents changes in accretable yield, or the excess of the security’s cash flows expected to be collected over the Company’s investment, solely as it pertains to the Company’s Non-Agency RMBS portfolio accounted for according to the provisions of ASC 310-30. For the Year Ended December 31, 2017 December 31, 2016 (dollars in thousands) Balance at beginning of period $ 1,550,110 $ 1,742,744 Purchases 20,962 79,156 Yield income earned (266,214 ) (282,800 ) Reclassification (to) from non-accretable difference 18,909 53,681 Sales and deconsolidation (20,178 ) (42,671 ) Balance at end of period $ 1,303,589 $ 1,550,110 The table below presents the outstanding principal balance and related amortized cost at December 31, 2017 and December 31, 2016 as it pertains to the Company’s Non-Agency RMBS portfolio accounted for according to the provisions of ASC 310-30. For the Year Ended December 31, 2017 December 31, 2016 (dollars in thousands) Outstanding principal balance: Beginning of period $ 3,138,265 $ 3,550,698 End of period $ 2,673,350 $ 3,138,265 Amortized cost: Beginning of period $ 1,695,079 $ 1,958,726 End of period $ 1,381,839 $ 1,695,079 The following tables present the gross unrealized losses and estimated fair value of the Company’s RMBS by length of time that such securities have been in a continuous unrealized loss position at December 31, 2017 and December 31, 2016 . All securities in an unrealized loss position have been evaluated by the Company for OTTI as discussed in Note 2(d). December 31, 2017 (dollars in thousands) Unrealized Loss Position for Less than 12 Months Unrealized Loss Position for 12 Months or More Total Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Non-Agency RMBS Senior $ 35,229 $ (182 ) 1 $ — $ — — $ 35,229 $ (182 ) 1 Senior, interest-only 28,129 (1,724 ) 27 120,120 (66,183 ) 120 148,249 (67,907 ) 147 Subordinated 235 (38 ) 7 6,261 (261 ) 5 6,496 (299 ) 12 Subordinated, interest-only — — — 945 (445 ) 3 945 (445 ) 3 Agency MBS Residential 660,103 (5,197 ) 21 1,471,464 (28,702 ) 93 2,131,567 (33,899 ) 114 Commercial 830,889 (11,695 ) 176 161,980 (4,404 ) 91 992,869 (16,099 ) 267 Interest-only 15,142 (641 ) 7 57,875 (7,103 ) 24 73,017 (7,744 ) 31 Total $ 1,569,727 $ (19,477 ) 239 $ 1,818,645 $ (107,098 ) 336 $ 3,388,372 $ (126,575 ) 575 December 31, 2016 (dollars in thousands) Unrealized Loss Position for Less than 12 Months Unrealized Loss Position for 12 Months or More Total Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Non-Agency RMBS Senior $ 12,384 $ (250 ) 3 $ — $ — — $ 12,384 $ (250 ) 3 Senior, interest-only 96,399 (13,600 ) 62 78,516 (43,931 ) 86 174,915 (57,531 ) 148 Subordinated 56,015 (412 ) 7 2,826 (824 ) 4 58,841 (1,236 ) 11 Subordinated, interest-only 748 (230 ) 2 11,276 (1,624 ) 3 12,024 (1,854 ) 5 Agency MBS Residential 2,338,910 (48,084 ) 106 54,943 (1,615 ) 1 2,393,853 (49,699 ) 107 Commercial 1,247,923 (45,802 ) 646 51,733 (4,035 ) 46 1,299,656 (49,837 ) 692 Interest-only 63,506 (2,170 ) 20 52,963 (7,098 ) 16 116,469 (9,268 ) 36 Total $ 3,815,885 $ (110,548 ) 846 $ 252,257 $ (59,127 ) 156 $ 4,068,142 $ (169,675 ) 1,002 At December 31, 2017 , the Company did not intend to sell any of its RMBS that were in an unrealized loss position, and it was not more likely than not that the Company would be required to sell these RMBS before recovery of their amortized cost basis, which may be at their maturity. With respect to RMBS held by consolidated VIEs, the ability of any entity to cause the sale by the VIE prior to the maturity of these RMBS is either expressly prohibited, not probable, or is limited to specified events of default, none of which have occurred as of December 31, 2017 . Gross unrealized losses on the Company’s Agency residential and commercial MBS (excluding Agency MBS which are reported at fair value with changes in fair value recorded in earnings) were $41 million and $100 million as of December 31, 2017 and December 31, 2016 , respectively. Given the inherent credit quality of Agency MBS, the Company does not consider any of the current impairments on its Agency MBS to be credit related. In evaluating whether it is more likely than not that it will be required to sell any impaired security before its anticipated recovery, which may be at their maturity, the Company considers the significance of each investment, the amount of impairment, the projected future performance of such impaired securities, as well as the Company’s current and anticipated leverage capacity and liquidity position. Based on these analyses, the Company determined that at December 31, 2017 and December 31, 2016 , unrealized losses on its Agency MBS were temporary. Gross unrealized losses on the Company’s Non-Agency RMBS (excluding Non-Agency MBS which are reported at fair value with changes in fair value recorded in earnings) were $283 thousand and $485 thousand at December 31, 2017 and December 31, 2016 , respectively. Based upon the most recent evaluation, the Company does not consider these unrealized losses to be indicative of OTTI and does not believe that these unrealized losses are credit related, but rather are due to other factors. The Company has reviewed its Non-Agency RMBS that are in an unrealized loss position to identify those securities with losses that are other-than-temporary based on an assessment of changes in cash flows expected to be collected for such RMBS, which considers recent bond performance and expected future performance of the underlying collateral. A summary of the OTTI included in earnings for the years ended December 31, 2017 , 2016 and 2015 are presented below. For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Total other-than-temporary impairment losses $ (5,169 ) $ (9,589 ) $ (8,700 ) Portion of loss recognized in other comprehensive income (loss) (56,687 ) (48,398 ) (58,744 ) Net other-than-temporary credit impairment losses $ (61,856 ) $ (57,987 ) $ (67,444 ) The following table presents a roll forward of the credit loss component of OTTI on the Company’s Non-Agency RMBS for which a portion of loss was previously recognized in OCI. The table delineates between those securities that are recognizing OTTI for the first time as opposed to those that have previously recognized OTTI. For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Cumulative credit loss beginning balance $ 556,485 $ 529,112 $ 507,548 Additions: Other-than-temporary impairments not previously recognized 12,669 25,959 41,233 Reductions for securities sold or deconsolidated during the period (12,405 ) (9,429 ) (19,746 ) Increases related to other-than-temporary impairments on securities with previously recognized other-than-temporary impairments 47,211 32,027 26,138 Reductions for increases in cash flows expected to be collected over the remaining life of the securities (12,439 ) (21,184 ) (26,061 ) Cumulative credit impairment loss ending balance $ 591,521 $ 556,485 $ 529,112 Cash flows generated to determine net other-than-temporary credit impairment losses recognized in earnings are estimated using significant unobservable inputs. The significant inputs used to measure the component of OTTI recognized in earnings for the Company’s Non-Agency RMBS for the periods reported are summarized as follows: For the Year Ended December 31, 2017 December 31, 2016 Loss Severity Weighted Average 64% 58% Range 28% - 89% 25% - 85% 60+ days delinquent Weighted Average 21% 21% Range 11% - 27% 0% - 40% Credit Enhancement (1) Weighted Average 16% 25% Range 0% - 50% 0% - 100% 3 Month CPR Weighted Average 10% 7% Range 0% - 24% 0% - 27% 12 Month CPR Weighted Average 11% 6% Range 1% - 19% 1% - 24% (1) Calculated as the combined credit enhancement to the Re-REMIC and underlying from each of their respective capital structures. The following tables present a summary of unrealized gains and losses at December 31, 2017 and December 31, 2016 . IO MBS included in the tables below represent the right to receive a specified portion of the contractual interest cash flows of the underlying principal balance of specific securities. At December 31, 2017 , IO MBS had a fair value of $323 million , an amortized cost of $382 million and net unrealized losses of $59 million . At December 31, 2016 , IO MBS had a fair value of $410 million , an amortized cost of $458 million and net unrealized losses of $48 million . All changes in fair value of IOs are reflected in Net Income in the Consolidated Statements of Operations. December 31, 2017 (dollars in thousands) Gross Unrealized Gain Included in Accumulated Other Comprehensive Income Gross Unrealized Gain Included in Cumulative Earnings Total Gross Unrealized Gain Gross Unrealized Loss Included in Accumulated Other Comprehensive Income Gross Unrealized Loss Included in Cumulative Earnings Total Gross Unrealized Loss Non-Agency RMBS Senior $ 754,234 $ — $ 754,234 $ (182 ) $ — $ (182 ) Senior, interest-only — 15,761 15,761 — (67,907 ) (67,907 ) Subordinated 62,989 3,715 66,704 (102 ) (197 ) (299 ) Subordinated, interest-only — 902 902 — (445 ) (445 ) Agency MBS Residential 5,706 — 5,706 (29,083 ) (4,816 ) (33,899 ) Commercial 15,462 1,579 17,041 (12,122 ) (3,977 ) (16,099 ) Interest-only — 834 834 — (7,744 ) (7,744 ) Total $ 838,391 $ 22,791 $ 861,182 $ (41,489 ) $ (85,086 ) $ (126,575 ) December 31, 2016 (dollars in thousands) Gross Unrealized Gain Included in Accumulated Other Comprehensive Income Gross Unrealized Gain Included in Cumulative Earnings Total Gross Unrealized Gain Gross Unrealized Loss Included in Accumulated Other Comprehensive Income Gross Unrealized Loss Included in Cumulative Earnings Total Gross Unrealized Loss Non-Agency RMBS Senior $ 732,133 $ — $ 732,133 $ (250 ) $ — $ (250 ) Senior, interest-only — 18,674 18,674 — (57,531 ) (57,531 ) Subordinated 74,584 3,273 77,857 (235 ) (1,001 ) (1,236 ) Subordinated, interest-only — — — — (1,854 ) (1,854 ) Agency MBS Residential 11,235 — 11,235 (49,699 ) — (49,699 ) Commercial 175 — 175 (49,837 ) — (49,837 ) Interest-only — 1,893 1,893 — (9,268 ) (9,268 ) Total $ 818,127 $ 23,840 $ 841,967 $ (100,021 ) $ (69,654 ) $ (169,675 ) Changes in prepayments, actual cash flows, and cash flows expected to be collected, among other items, are affected by the collateral characteristics of each asset class. The Company chooses assets for the portfolio after carefully evaluating each investment’s risk profile. The following tables provide a summary of the Company’s MBS portfolio at December 31, 2017 and December 31, 2016 . December 31, 2017 Principal or Notional Value Weighted Average Amortized Weighted Average Fair Value Weighted Average Weighted Average Yield at Period-End (1) Non-Agency RMBS Senior $ 2,733,926 $ 54.04 $ 81.62 4.6 % 16.7 % Senior, interest-only 4,862,461 5.41 4.34 1.3 % 8.0 % Subordinated 501,455 66.77 80.01 4.1 % 9.6 % Subordinated, interest-only 201,378 3.66 3.89 0.8 % 11.8 % Agency MBS Residential pass-through 2,227,128 105.53 104.27 3.8 % 2.9 % Commercial pass-through 1,894,594 102.26 102.31 3.6 % 3.2 % Interest-only 3,021,840 3.68 3.45 0.7 % 3.4 % (1) Bond Equivalent Yield at period end. December 31, 2016 Principal or Notional Value at Period-End Weighted Average Amortized Weighted Average Fair Value Weighted Average Weighted Average Yield at Period-End (1) Non-Agency RMBS Senior $ 3,190,947 $ 55.76 $ 78.69 4.3 % 15.5 % Senior, interest-only 5,648,339 5.18 4.49 1.5 % 11.7 % Subordinated 673,259 70.83 82.21 3.8 % 9.2 % Subordinated, interest-only 266,927 5.20 4.50 1.1 % 13.5 % Agency MBS Residential pass-through 2,594,570 105.78 104.29 3.9 % 3.0 % Commercial pass-through 1,331,543 102.64 98.91 3.6 % 2.9 % Interest-only 3,356,491 4.53 4.31 0.8 % 3.5 % (1) Bond Equivalent Yield at period end. The following table presents the weighted average credit rating of the Company’s Non-Agency RMBS portfolio at December 31, 2017 and December 31, 2016 . December 31, 2017 December 31, 2016 AAA 0.3 % 0.3 % AA 0.3 % 0.3 % A 0.6 % 0.7 % BBB 1.9 % 0.7 % BB 2.5 % 3.0 % B 2.3 % 3.9 % Below B 59.6 % 67.2 % Not Rated 32.5 % 23.9 % Total 100.0 % 100.0 % Actual maturities of MBS are generally shorter than the stated contractual maturities. Actual maturities of the Company’s MBS are affected by the contractual lives of the underlying mortgages, periodic payments of principal and prepayments of principal. The following tables provide a summary of the fair value and amortized cost of the Company’s MBS at December 31, 2017 and December 31, 2016 according to their estimated weighted-average life classifications. The weighted-average lives of the MBS in the tables below are based on lifetime expected prepayment rates using an industry prepayment model for the Agency MBS portfolio and the Company’s prepayment assumptions for the Non-Agency RMBS. The prepayment model considers current yield, forward yield, steepness of the interest rate curve, current mortgage rates, mortgage rates of the outstanding loan, loan age, margin, and volatility. December 31, 2017 (dollars in thousands) Weighted Average Life Less than one year Greater than one year and less than five years Greater than five years and less than ten years Greater than ten years Total Fair value Non-Agency RMBS Senior $ 2,179 $ 681,086 $ 910,234 $ 637,916 $ 2,231,415 Senior interest-only 19 54,107 72,702 84,022 210,850 Subordinated — 75,495 121,555 204,175 401,225 Subordinated interest-only — 7,165 661 — 7,826 Agency MBS Residential — 21,777 2,300,403 — 2,322,180 Commercial — 45,770 16,559 1,875,952 1,938,281 Interest-only — 74,490 25,271 4,606 104,367 Total fair value $ 2,198 $ 959,890 $ 3,447,385 $ 2,806,671 $ 7,216,144 Amortized cost Non-Agency RMBS Senior $ 2,124 $ 493,965 $ 569,458 $ 411,816 $ 1,477,363 Senior interest-only 1,271 73,758 94,145 93,822 262,996 Subordinated — 61,987 91,044 181,789 334,820 Subordinated interest-only — 6,355 1,014 — 7,369 Agency MBS Residential — 22,069 2,328,304 — 2,350,373 Commercial — 47,170 17,176 1,872,993 1,937,339 Interest-only — 79,356 27,582 4,339 111,277 Total amortized cost $ 3,395 $ 784,660 $ 3,128,723 $ 2,564,759 $ 6,481,537 December 31, 2016 (dollars in thousands) Weighted Average Life Less than one year Greater than one year and less than five years Greater than five years and less than ten years Greater than ten years Total Fair value Non-Agency RMBS Senior $ 25,612 $ 508,979 $ 1,267,000 $ 709,412 $ 2,511,003 Senior interest-only 417 37,796 115,780 99,546 253,539 Subordinated — 94,793 238,630 220,075 553,498 Subordinated interest-only — — 12,024 — 12,024 Agency MBS Residential — 429,869 2,276,109 — 2,705,978 Commercial — 47,354 16,833 1,252,788 1,316,975 Interest-only — 75,863 63,715 5,222 144,800 Total fair value $ 26,029 $ 1,194,654 $ 3,990,091 $ 2,287,043 $ 7,497,817 Amortized cost Non-Agency RMBS Senior $ 21,423 $ 403,250 $ 868,624 $ 485,823 $ 1,779,120 Senior interest-only 1,992 50,252 134,642 105,510 292,396 Subordinated — 76,287 195,538 205,052 476,877 Subordinated interest-only — — 13,878 — 13,878 Agency MBS Residential — 438,270 2,306,172 — 2,744,442 Commercial — 49,027 17,247 1,300,363 1,366,637 Interest-only — 77,598 69,333 5,244 152,175 Total amortized cost $ 23,415 $ 1,094,684 $ 3,605,434 $ 2,101,992 $ 6,825,525 The Non-Agency RMBS portfolio is subject to credit risk. The Non-Agency RMBS portfolio is primarily collateralized by Alt-A first lien mortgages. An Alt-A mortgage is a type of U.S. mortgage that, for various reasons, is considered riskier than A-paper, or prime, and less risky than subprime, the riskiest category. Alt-A interest rates, which are determined by credit risk, therefore tend to be between those of prime and subprime home loans. Typically, Alt-A mortgages are characterized by borrowers with less than full documentation, lower credit scores and higher loan-to-value ratios. At origination of the loan, Alt-A mortgage securities are defined as Non-Agency RMBS where (i) the underlying collateral has weighted average FICO scores between 680 and 720 or (ii) the FICO scores are greater than 720 and RMBS have 30% or less of the underlying collateral composed of full documentation loans. At December 31, 2017 and December 31, 2016 , 66% and 68% of the Non-Agency RMBS collateral was classified as Alt-A, respectively. At December 31, 2017 and December 31, 2016 , 13% and 14% of the Non-Agency RMBS collateral was classified as prime, respectively. The remaining Non-Agency RMBS collateral is classified as subprime. The Non-Agency RMBS in the Portfolio have the following collateral characteristics at December 31, 2017 and December 31, 2016 . December 31, 2017 December 31, 2016 Weighted average maturity (years) 20.7 21.6 Weighted average amortized loan to value (1) 64.4 % 66.5 % Weighted average FICO (2) 697 698 Weighted average loan balance (in thousands) $ 314 $ 319 Weighted average percentage owner occupied 84.4 % 83.2 % Weighted average percentage single family residence 66.3 % 65.8 % Weighted average current credit enhancement 2.2 % 2.3 % Weighted average geographic concentration of top four states CA 31.7 % CA 32.1 % NY 8.5 % FL 8.1 % FL 8.3 % NY 7.9 % NJ 2.7 % NJ 2.7 % (1) Value represents appraised value of the collateral at the time of loan origination. (2) FICO as determined at the time of loan origination. The table below presents the origination year of the underlying loans related to the Company’s portfolio of Non-Agency RMBS at December 31, 2017 and December 31, 2016 . Origination Year December 31, 2017 December 31, 2016 2003 and prior 3.6 % 3.6 % 2004 4.3 % 4.2 % 2005 20.8 % 20.2 % 2006 38.2 % 38.0 % 2007 30.4 % 31.3 % 2008 1.8 % 1.8 % 2009 and later 0.9 % 0.9 % Total 100.0 % 100.0 % Gross realized gains and losses are recorded in “Net realized gains (losses) on sales of investments” on the Company’s Consolidated Statements of Operations. The proceeds and gross realized gains and gross realized losses from sales of investments for the years ended December 31, 2017 , 2016 and 2015 are as follows: For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Proceeds from sales $ 812,005 $ 2,719,329 $ 6,244,613 Gross realized gains 17,538 28,572 94,618 Gross realized losses (8,415 ) (10,417 ) (17,544 ) Net realized gain (loss) $ 9,123 $ 18,155 $ 77,074 Included in the gross realized gains for the year ended December 31, 2017 in the table above are exchanges of securities with a fair value of $63 million . The Company exchanged its investment in a re-remic security for the underlying collateral supporting the group related to the exchanged asset. These exchanges were treated as non-cash sales and purchases and resulted in a realized gain of $9 million , reflected in earnings for the year ended December 31, 2017 . For the year ended December 31, 2016, the fair value of these exchanges of securities was $65 million and resulted in a realized gain of $13 million . For the year ended December 31, 2015, the fair value of these exchanges of securities was $95 million and resulted in a realized gain of $24 million .

Loans Held for Investment

Loans Held for Investment	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Loans Held for Investment	Loans Held for Investment The Loans held for investment is comprised primarily of loans collateralized by seasoned subprime residential mortgages. Additionally, it includes non-conforming, single family, owner occupied, jumbo, prime residential mortgages. At December 31, 2017 , all Loans held for investment are carried at fair value. See Note 5 for a discussion on how the Company determines the fair values of the Loans held for investment. As changes in the fair value of these loans are reflected in earnings, the Company does not estimate or record a loan loss provision. The total amortized cost of our Loans held for investments was $13.3 billion and $8.6 billion as of December 31, 2017 and December 31, 2016 , respectively. The following table provides a summary of the changes in the carrying value of Loans held for investment at fair value at December 31, 2017 and December 31, 2016 : For the Year Ended December 31, 2017 December 31, 2016 (dollars in thousands) Balance, beginning of period $ 8,753,653 $ 4,768,416 Purchases 6,539,765 4,897,370 Principal paydowns (1,788,409 ) (1,022,414 ) Sales and settlements 2,876 5,007 Net periodic accretion (amortization) (35,803 ) (41,363 ) Change in fair value 206,181 146,637 Balance, end of period $ 13,678,263 $ 8,753,653 The primary cause of the change in fair value is due to market demand for mortgage loans. Residential mortgage loans The loan portfolio for all residential mortgages were originated during the following years: Origination Year December 31, 2017 December 31, 2016 2002 and prior 7.5 % 8.9 % 2003 6.7 % 5.2 % 2004 14.6 % 11.9 % 2005 20.4 % 20.5 % 2006 23.1 % 22.0 % 2007 19.0 % 20.9 % 2008 6.0 % 6.5 % 2009 0.7 % 0.6 % 2010 and later 2.0 % 3.5 % Total 100.0 % 100.0 % The following table presents a summary of key characteristics of the residential loan portfolio at December 31, 2017 and December 31, 2016 : December 31, 2017 December 31, 2016 Number of loans 149,172 95,155 Weighted average maturity (years) 18.8 19.8 Weighted average loan to value (1) 88.0 % 86.9 % Weighted average FICO (1) 631 627 Weighted average loan balance (in thousands) $ 91 $ 93 Weighted average percentage owner occupied 95.0 % 96.6 % Weighted average percentage single family residence 86.0 % 85.0 % Weighted average geographic concentration of top five states CA 9.0 % CA 10.0 % FL 7.2 % FL 6.7 % OH 6.1 % OH 6.5 % PA 5.6 % VA 5.9 % VA 5.5 % NC 5.1 % (1) As provided by the Trustee. The following tables show various characteristics of our residential loan portfolio and outstanding principal balance of the loans that are 30 days delinquent and greater for the years ended December 31, 2017 and 2016, respectively. December 31, 2017 (dollars in thousands) Loan Balance Number of Loans Interest Rate Maturity Date Total Principal 30-89 Days Delinquent 90+ Days Delinquent Held-for-Investment at fair value: Adjustable rate loans: $1 to $250 9,227 1.00% to 18.74% 9/1/1992 - 6/1/2057 $ 827,020 $ 95,952 $ 46,343 $250 to $500 529 2.00% to 11.88% 11/1/2028 - 12/1/2056 171,266 19,289 11,855 $500 to $750 67 2.00% to 9.25% 1/1/2034 - 9/1/2046 39,212 3,041 2,382 $750 to $1,000 9 3.88% to 5.55% 1/1/2035 - 12/1/2045 7,663 757 — Over $1,000 8 3.88% to 4.00% 7/1/2037 - 8/1/2039 13,702 2,705 1,164 9,840 $ 1,058,863 $ 121,744 $ 61,744 Hybrid loans: $500 to $750 1 6.88% to 6.88% 1/1/2038 - 1/1/2038 $ 702 $ — $ — 1 $ 702 $ — $ — Fixed loans: $1 to $250 133,437 0.00% to 24.00% 9/1/1994 - 5/1/2062 $ 10,371,829 $ 960,564 $ 562,271 $250 to $500 5,324 0.00% to 12.52% 4/1/2018 - 11/1/2065 1,713,839 188,257 114,616 $500 to $750 440 2.00% to 10.69% 7/1/2031 - 9/1/2057 258,058 12,789 13,459 $750 to $1,000 99 2.00% to 7.69% 3/1/2013 - 12/1/2055 84,701 1,706 877 Over $1,000 31 3.00% to 5.75% 12/1/2040 - 7/1/2056 37,828 1,155 — 139,331 $ 12,466,255 $ 1,164,471 $ 691,223 Total 149,172 $ 13,525,820 $ 1,286,215 $ 752,967 The foreclosure, bankruptcy and REO balances on our loans were $200 million , $273 million and $31 million , respectively, as of December 31, 2017, which are included in the table above. December 31, 2016 (dollars in thousands) Loan Balance Number of Loans Interest Rate Maturity Date Total Principal 30-89 Days Delinquent 90+ Days Delinquent Held-for-Investment at fair value: Adjustable rate loans: $1 to $250 6,417 1.38% to 15.20% 2/1/2003 - 10/1/2056 $ 609,584 $ 67,705 $ 25,102 $250 to $500 458 2.13% to 10.00% 4/1/2030 - 9/1/2055 147,410 22,821 7,684 $500 to $750 45 2.00% to 9.25% 7/1/2034 - 9/1/2046 26,383 $ 3,033 1,131 $750 to $1,000 7 3.13% to 5.17% 1/1/2038 - 12/1/2045 5,754 $ 768 — Over $1,000 5 3.13% to 3.38% 1/1/2038 - 4/1/2038 6,641 $ — 1,428 6,932 795,772 94,326 35,345 Hybrid loans: $1 to $250 2 6.67% to 6.83% 8/1/2037 - 9/1/2037 $ 190 $ 97 $ — $250 to $500 1 5.88% to 5.88% 7/1/2037 - 7/1/2037 496 — — $500 to $750 3 5.63% to 6.88% 7/1/2037 - 3/1/2038 1,842 — — $750 to $1,000 1 5.75% to 5.75% 4/1/2037 - 4/1/2037 940 — — 7 $ 3,468 $ 97 $ — Fixed loans: $1 to $250 83,925 0.00% to 24.00% 7/1/2002 - 5/1/2062 $ 6,487,251 $ 603,388 $ 424,980 $250 to $500 3,769 0.00% to 12.52% 5/1/2018 - 10/1/2065 1,225,999 136,702 80,984 $500 to $750 381 2.00% to 10.69% 5/1/2032 - 9/1/2057 223,638 9,531 5,788 $750 to $1,000 103 3.75% to 7.29% 4/1/2037 - 5/1/2047 87,680 — 1,746 Over $1,000 38 3.25% to 7.13% 3/1/2013 - 8/1/2046 44,975 — — 88,216 $ 8,069,543 $ 749,621 $ 513,498 Total 95,155 $ 8,868,783 $ 844,044 $ 548,843 The foreclosure, bankruptcy and REO balances on our loans were $203 million , $207 million and $41 million , respectively, as of December 31, 2016, which are included in the table above. The fair value of residential mortgage loans 90 days or more past due was $577 million and $449 million as of December 31, 2017 and December 31, 2016 , respectively.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company applies fair value guidance in accordance with GAAP to account for its financial instruments. The Company categorizes its financial instruments, based on the priority of the inputs to the valuation technique, into a three-level fair value hierarchy. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). If the inputs used to measure the financial instruments fall within different levels of the hierarchy, the categorization is based on the lowest level input that is significant to the fair value measurement of the instrument. Financial assets and liabilities recorded at fair value on the Consolidated Statements of Financial Condition or disclosed in the related notes are categorized based on the inputs to the valuation techniques as follows: Level 1 – inputs to the valuation methodology are quoted prices (unadjusted) for identical assets and liabilities in active markets. Level 2 – inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level 3 – inputs to the valuation methodology are unobservable and significant to fair value. Fair value measurements categorized within Level 3 are sensitive to changes in the assumptions or methodology used to determine fair value and such changes could result in a significant increase or decrease in the fair value. Any changes to the valuation methodology are reviewed by management to ensure the changes are appropriate. As markets and products evolve and the pricing for certain products becomes more transparent, the Company will continue to refine its valuation methodologies. The methodology utilized by the Company for the periods presented is unchanged. The methods used to produce a fair value calculation may not be indicative of net realizable value or reflective of future fair values. Furthermore, the Company believes its valuation methods are appropriate and consistent with other market participants. Using different methodologies, or assumptions, to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. The Company uses inputs that are current as of the measurement date, which may include periods of market dislocation, during which price transparency may be reduced. During times of market dislocation, the observability of prices and inputs can be difficult for certain investments. If third party pricing services are unable to provide a price for an asset, or if the price provided by them is deemed unreliable by the Company, then the asset will be valued at its fair value as determined by the Company without validation to third-party pricing. Illiquid investments typically experience greater price volatility as an active market does not exist. Observability of prices and inputs can vary significantly from period to period and may cause instruments to change classifications within the three level hierarchy. A description of the methodologies utilized by the Company to estimate the fair value of its financial instruments by instrument class follows: Agency MBS and Non-Agency RMBS The Company determines the fair value of all of its investment securities based on discounted cash flows utilizing an internal pricing model that incorporates factors such as coupon, prepayment speeds, loan size, collateral composition, borrower characteristics, expected interest rates, life caps, periodic caps, reset dates, collateral seasoning, delinquency, expected losses, expected default severity, credit enhancement, and other pertinent factors. To corroborate that the estimates of fair values generated by these internal models are reflective of current market prices, the Company compares the fair values generated by the model to non-binding independent prices provided by two independent third party pricing services. For certain highly liquid asset classes, such as Agency fixed-rate pass-through bonds, the Company’s valuations are also compared to quoted prices for To-Be-Announced (“TBA”) securities. Each quarter the Company develops thresholds which are determined utilizing current bid/ask spreads, liquidity, price volatility and other factors as appropriate. If internally developed model prices differ from the independent prices provided by greater than a market derived predetermined threshold for the period, the Company highlights these differences for further review, both internally and with the third party pricing service. The Company obtains the inputs used by the third party pricing services and compares them to the Company’s inputs. The Company updates its own inputs if the Company determines the third party pricing inputs more accurately reflect the current market environment. If the Company believes that its internally developed inputs more accurately reflect the current market environment, it will request that the third party pricing service review market factors that may not have been considered by the third party pricing service and provide updated prices. The Company reconciles and resolves all pricing differences in excess of the predetermined thresholds before a final price is established. At December 31, 2017 , four investment holdings with an internally developed fair value of $25 million had a difference between the model generated prices and third party prices provided in excess of the derived predetermined threshold for the period. The internally developed prices were $3 million lower than the third party prices provided of $28 million . After review and discussion, the Company affirmed and valued the investments at the lower internally developed prices. No other differences were noted at December 31, 2017 in excess of the derived predetermined threshold for the period. At December 31, 2016, ten investment holdings with an internally developed fair value of $123 million had a difference between the model generated prices and third party prices provided in excess of the derived predetermined threshold for the period. The internally developed prices were $16 million higher than the third party prices provided of $107 million . After review and discussion, the Company affirmed and valued the investments at the higher internally developed prices. The Company’s estimate of prepayment, default and severity curves all involve judgment and assumptions that are deemed to be significant to the fair value measurement process, which renders the resulting Non-Agency RMBS fair value estimates Level 3 inputs in the fair value hierarchy. As the fair values of Agency MBS are more observable, these investments are classified as level 2 in the fair value hierarchy. Loans Held for Investment Loans consisting of seasoned subprime residential mortgage loans: The Company estimates the fair value of its Loans held for investment consisting of seasoned subprime residential mortgage loans on a loan by loan basis using an internally developed model which compares the loan held by the Company with a loan currently offered in the market. The loan price is adjusted in the model by considering the loan factors which would impact the value of a loan. These loan factors include: loan coupon as compared to coupon currently available in the market, FICO, loan-to-value ratios, delinquency history, owner occupancy, and property type, among other factors. A baseline is developed for each significant loan factor and adjusts the price up or down depending on how that factor for each specific loan compares to the baseline rate. Generally, the most significant impact on loan value is the loan interest rate as compared to interest rates currently available in the market and delinquency history. These two factors are based on relevant observable inputs. The Company also monitors market activity to identify trades which may be used to compare internally developed prices; however, as the portfolio of loans held at fair value is a seasoned subprime pool of mortgage loans, comparable loan pools are not common or directly comparable. There are limited transactions in the market place to develop a comprehensive direct range of values. However, if market data becomes available, the Company will compare this data to the internally developed prices to ensure reasonableness of the valuation. The Company reviews the fair values generated by the model to determine whether prices are reflective of the current market by corroborating its estimates of fair value by comparing the results to non-binding independent prices provided by two independent third party pricing services for the loan portfolio. Each quarter the Company develops thresholds which are determined utilizing the securitization market. If the internally developed fair values of the loan pools differ from the independent prices provided by greater than a predetermined threshold for the period, the Company highlights these differences for further review, both internally and with the third party pricing service. The Company obtains certain inputs used by the third party pricing services and evaluates them for reasonableness. The Company updates its own model if the Company determines the third party pricing inputs more accurately reflect the current market environment or observed information from the third party vendors. If the Company believes that its internally developed inputs more accurately reflect the current market environment, it will request that the third party pricing service review market factors that may not have been considered by the third party pricing service. The Company reconciles and resolves all pricing differences in excess of the predetermined thresholds before a final price is established. At December 31, 2017, there were no pricing differences in excess of the predetermined thresholds between the model generated prices and third party prices. At December 31, 2016 , the internally developed fair values of loan pools of $1.60 billion had a difference between the model generated prices and third party prices provided in excess of the derived predetermined threshold for the period. The internally developed prices were $50 million higher than the third party prices provided of $1.55 billion . After review and discussion, the Company affirmed and valued the investments at the higher internally developed prices. No other differences were noted at December 31, 2016 in excess of the derived predetermined threshold for the period. The Company’s estimates of fair value of Loans held for investment involve management judgment and assumptions that are deemed to be significant to the fair value measurement process, which renders the resulting fair value estimates level 3 inputs in the fair value hierarchy. Loans collateralized by jumbo, prime residential mortgages : The loans collateralized by jumbo, prime residential mortgages are carried at fair value. The loans are held as part of a consolidated Collateralized Financing Entity (“CFE”). A CFE is a variable interest entity that holds financial assets, issues beneficial interests in those assets and has no more than nominal equity and the beneficial interests have contractual recourse only to the related assets of the CFE. Accounting guidance for CFEs allow the Company to elect to measure the CFE’s financial assets using the fair value of the CFE’s financial liabilities as the fair values of the financial liabilities of the CFE are more observable. Therefore, the fair value of the loans collateralized by jumbo, prime residential mortgages is based on the fair value of the financial liabilities. See discussion of the fair value of Securitized Debt, collateralized by Loans Held for Investment at fair value below. As the more observable financial liabilities are considered level 3 in the fair value hierarchy, the Loans collateralized by jumbo, prime residential mortgages are also level 3 in the fair value hierarchy. Securitized Debt, collateralized by Non-Agency RMBS The Company carries securitized debt, collateralized by Non-Agency RMBS at the principal balance outstanding plus unamortized premiums, less unaccreted discounts recorded in connection with the financing of the loans or RMBS with third parties. The Company estimates the fair value of securitized debt, collateralized by Non-Agency RMBS by estimating the future cash flows associated with the underlying assets collateralizing the secured debt outstanding. The Company models the fair value of each underlying asset by considering, among other items, the structure of the underlying security, coupon, servicer, delinquency, actual and expected defaults, actual and expected default severities, reset indices, and prepayment speeds in conjunction with market research for similar collateral performance and management’s expectations of general economic conditions in the sector and other economic factors. This process, including the review process, is consistent with the process used for Agency MBS and Non-Agency RMBS using internal models. For further discussion of the valuation process and benchmarking process, see Agency MBS and Non-Agency RMBS discussion herein. The Company’s estimates of fair value of securitized debt, collateralized by Non-Agency RMBS involve management’s judgment and assumptions that are deemed to be significant to the fair value measurement process, which renders the resulting fair value estimates level 3 inputs in the fair value hierarchy. Securitized Debt, collateralized by Loans Held for Investment The process for determining the fair value of securitized debt, collateralized by loans held for investment based on discounted cash flows utilizing an internal pricing model that incorporates factors such as coupon, prepayment speeds, loan size, collateral composition, borrower characteristics, expected interest rates, life caps, periodic caps, reset dates, collateral seasoning, expected losses, expected default severity, credit enhancement, and other pertinent factors. This process, including the review process, is consistent with the process used for Agency MBS and Non-Agency RMBS using internal models. For further discussion of the valuation process and benchmarking process, see Agency MBS and Non-Agency RMBS discussion herein. The Company’s estimates of fair value of securitized debt, collateralized by loans held for investment involve management’s judgment and assumptions that are deemed to be significant to the fair value measurement process, which renders the resulting fair value estimates level 3 inputs in the fair value hierarchy. Fair value option The table below shows the unpaid principal, fair value and impact of change in fair value on each of the financial instruments carried with fair value option as of December 31, 2017 and 2016 , respectively: December 31, 2017 (dollars in thousands) Unpaid Fair Value Quarter to Date Gain/(Loss) on Change in Fair Value Year to Date Gain/(Loss) on Change in Fair Value Assets: Non-agency RMBS Subordinated N/A $ 13,993 $ (545 ) $ 1,246 Senior, interest-only 4,862,461 210,850 3,156 (13,290 ) Subordinated, interest-only 201,378 7,826 1,836 2,311 Agency MBS Residential Pass-through 577,522 602,829 (2,359 ) (4,816 ) Commercial Pass-through 564,379 570,105 (546 ) (2,398 ) Interest-only 3,021,840 104,367 (367 ) 465 Loans held for investment, at fair value 13,525,820 13,678,263 (65,643 ) 206,181 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 9,395,854 9,388,657 16,831 (78,289 ) December 31, 2016 (dollars in thousands) Unpaid Fair Value Quarter to Date Gain/(Loss) on Change in Fair Value Year to Date Gain/(Loss) on Change in Fair Value Assets: Non-agency RMBS Subordinated N/A $ 18,602 $ (1,983 ) $ 5,568 Senior, interest-only 5,648,339 253,539 (26,844 ) (4,512 ) Subordinated, interest-only 266,927 12,024 (1,169 ) 2,118 Agency MBS Interest-only 3,356,491 144,800 (920 ) (490 ) Loans held for investment, at fair value 8,868,783 8,753,653 32,991 146,635 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 7,059,265 6,941,097 (22,738 ) (89,767 ) Derivatives Interest Rate Swaps and Swaptions The Company uses clearing exchange market prices to determine the fair value of its exchange cleared interest rate swaps. For bi-lateral swaps, the Company determines the fair value based on the net present value of expected future cash flows on the swap. The Company uses option pricing model to determine the fair value of its swaptions. For bi-lateral swaps and swaptions, the Company compares its own estimate of fair value with counterparty prices to evaluate for reasonableness. Both the clearing exchange and counter-party pricing quotes, incorporate common market pricing methods, including a spread measurement to the Treasury yield curve or interest rate swap curve as well as underlying characteristics of the particular contract. Interest rate swaps and swaptions are modeled by the Company by incorporating such factors as the term to maturity, swap curve, overnight index swap rates, and the payment rates on the fixed portion of the interest rate swaps. The Company has classified the characteristics used to determine the fair value of interest rate swaps as Level 2 inputs in the fair value hierarchy. Treasury Futures The fair value of Treasury futures is determined by quoted market prices in an active market. The Company has classified the characteristics used to determine the fair value of Treasury futures as Level 1 inputs in the fair value hierarchy. Repurchase Agreements Repurchase agreements are collateralized financing transactions utilized by the Company to acquire investment securities. Due to the short term nature of these financial instruments, the Company estimates the fair value of these repurchase agreements using the contractual obligation plus accrued interest payable. Short-term Financial Instruments The carrying value of cash and cash equivalents, accrued interest receivable, receivable for securities sold, dividends payable, payable for investments purchased and accrued interest payable are considered to be a reasonable estimate of fair value due to the short term nature and low credit risk of these short-term financial instruments. The Company’s financial assets and liabilities carried at fair value on a recurring basis, including the level in the fair value hierarchy, at December 31, 2017 and December 31, 2016 are presented below. December 31, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Counterparty and Cash Collateral, netting Total Assets: Non-Agency RMBS, at fair value $ — $ — $ 2,851,316 $ — $ 2,851,316 Agency MBS, at fair value — 4,364,828 — — 4,364,828 Loans held for investment, at fair value — — 13,678,263 — 13,678,263 Derivatives 3,553 46,978 — (1,617 ) 48,914 Liabilities: Securitized debt at fair value, collateralized by loans held for investment — — (9,388,657 ) — (9,388,657 ) Derivatives — (1,937 ) — 1,617 (320 ) December 31, 2016 (dollars in thousands) Level 1 Level 2 Level 3 Counterparty and Cash Collateral, netting Total Assets: Non-Agency RMBS, at fair value $ — $ — 3,330,063 $ — $ 3,330,063 Agency MBS, at fair value — 4,167,754 — — 4,167,754 Loans held for investment, at fair value — — 8,753,653 — 8,753,653 Derivatives 1,785 22,327 — (14,435 ) 9,677 Liabilities: Securitized debt at fair value, collateralized by loans held for investment — — (6,941,097 ) — (6,941,097 ) Derivatives — (17,225 ) — 14,875 (2,350 ) The table below provides a summary of the changes in the fair value of securities classified as Level 3 at December 31, 2017 and December 31, 2016 . Fair Value Reconciliation, Level 3 For the Year Ended, December 31, 2017 (dollars in thousands) Non-Agency RMBS Loans held for investment Securitized Debt Beginning balance Level 3 assets $ 3,330,063 $ 8,753,653 $ (6,941,097 ) Transfers in to Level 3 assets 6,112 — — Transfers out of Level 3 assets — — — Purchases 78,400 6,539,765 (5,173,430 ) Principal payments (568,339 ) (1,788,409 ) 1,787,368 Sales and Settlements (68,162 ) 2,876 1,056,765 Accretion (amortization) of purchase discounts 120,119 (35,803 ) (4,701 ) Gains (losses) included in net income Other than temporary credit impairment losses (59,881 ) — — Realized gains (losses) on sales and settlements 12,031 — (35,273 ) Net unrealized gains (losses) included in income (9,733 ) 206,181 (78,289 ) Gains (losses) included in other comprehensive income Total unrealized gains (losses) for the period 10,706 — — Ending balance Level 3 assets $ 2,851,316 $ 13,678,263 $ (9,388,657 ) Fair Value Reconciliation, Level 3 For the Year Ended, December 31, 2016 (dollars in thousands) Non-Agency RMBS Loans held for investment Securitized Debt Beginning balance Level 3 assets $ 3,675,841 $ 4,768,416 $ (3,720,496 ) Transfers in to Level 3 assets — — — Transfers out of Level 3 assets — — — Purchases 257,914 4,897,370 (4,797,255 ) Principal payments (532,696 ) (1,022,414 ) 1,059,854 Sales and Settlements (149,938 ) 5,007 608,816 Accretion (amortization) of purchase discounts 120,638 (41,363 ) (2,128 ) Gains (losses) included in net income Other than temporary credit impairment losses (57,986 ) — — Realized gains (losses) on sales and settlements 13,761 — (122 ) Net unrealized gains (losses) included in income 3,173 146,637 (89,766 ) Gains (losses) included in other comprehensive income Total unrealized gains (losses) for the period (644 ) — — Ending balance Level 3 assets $ 3,330,063 $ 8,753,653 $ (6,941,097 ) There were $6 million of IOs transferred to Level 3 and no transfers out from Level 3, during the year ended December 31, 2017 . There were no transfers to or from Level 3 for the year ended December 31, 2016 . The primary cause of the changes in fair value of the loans and the securitized debt are due to market demand for these instruments and changes in credit risk of the portfolio. The significant unobservable inputs used in the fair value measurement of the Company’s Non-Agency RMBS and securitized debt are the weighted average discount rates, constant prepayment speed (“CPR”), cumulative default rate, and the loss severity. Constant Prepayment Rates For securitized debt carried at fair value issued at a premium, as prepayment speeds increase, the amount of interest expense the Company recognizes decreases as the issued premium on the debt amortizes faster than expected. Conversely, decreases in prepayment speeds result in increased expense and can extend the period over which the Company amortizes the premium. For debt issued at a discount, as prepayment speeds increase, the amount of interest the Company expenses increases from the acceleration of the accretion of the discount into interest expense. Conversely, decreases in prepayment speeds result in decreased expense as the accretion of the discount into interest expense occurs over a longer period. Constant Default Rates Cumulative default rates represent an annualized rate of default on a group of mortgages. The constant default rate (“CDR”) represents the percentage of outstanding principal balances in the pool that are in default, which typically equates to the home being past 60-day and 90-day notices and in the foreclosure process. When default rates increase, expected cash flows on the underlying collateral decreases. When default rates decrease, expected cash flows on the underlying collateral increases. Loss Severity Loss severity rates reflect the amount of loss expected from a foreclosure and liquidation of the underlying collateral in the mortgage loan pool. When a mortgage loan is foreclosed the collateral is sold and the resulting proceeds are used to settle the outstanding obligation. In many circumstances, the proceeds from the sale do not fully repay the outstanding obligation. In these cases, a loss is incurred by the lender. Loss severity is used to predict how costly future losses are likely to be. An increase in loss severity results in a decrease in expected future cash flows. A decrease in loss severity results in an increase in expected future cash flows. Discount Rate The discount rate refers to the interest rate used in the discounted cash flow analysis to determine the present value of future cash flows. The discount rate takes into account not just the time value of money, but also the risk or uncertainty of future cash flows. An increased uncertainty of future cash flows results in a higher discount rate. The discount rate used to calculate the present value of the expected future cash flows is based on the discount rate implicit in the security as of the last measurement date. As discount rates move up, the discounted cash flows are reduced. Sensitivity of Significant Inputs – Non-Agency RMBS and securitized debt, collateralized by loans held for investment Prepayment speeds, as reflected by the CPR, vary according to interest rates, the type of financial instrument, conditions in financial markets, and other factors, none of which can be predicted with any certainty. In general, when interest rates rise, it is relatively less attractive for borrowers to refinance their mortgage loans, and as a result, prepayment speeds tend to decrease. When interest rates fall, prepayment speeds tend to increase. For RMBS investments purchased at a premium, as prepayment speeds increase, the amount of income the Company earns decreases as the purchase premium on the bonds amortizes faster than expected. Conversely, decreases in prepayment speeds result in increased income and can extend the period over which the Company amortizes the purchase premium. For RMBS investments purchased at a discount, as prepayment speeds increase, the amount of income the Company earns increases from the acceleration of the accretion of the discount into interest income. Conversely, decreases in prepayment speeds result in decreased income as the accretion of the purchase discount into interest income occurs over a longer period. A summary of the significant inputs used to estimate the fair value of Non-Agency RMBS held for investment at fair value as of December 31, 2017 and December 31, 2016 follows: December 31, 2017 December 31, 2016 Significant Inputs Significant Inputs Weighted Average Discount Rate CPR CDR Loss Severity Weighted Average Discount Rate CPR CDR Loss Severity Range Range Non-Agency RMBS Senior 4.4% 1% -45% 0% -55% 35% -89% 5.4% 1% -35% 0% -22% 35% -95% Senior interest-only 11.2% 3% -25% 0% -50% 35% -95% 12.5% 3% -30% 0% -22% 35% -95% Subordinated 5.8% 1% -20% 0% -33% 35% -69% 6.2% 1% -25% 0% -18% 0% -79% Subordinated interest-only 12.0% 6% -22% 0% -9% 35% -63% 13.2% 6% -15% 0% -11% 35% -76% A summary of the significant inputs used to estimate the fair value of securitized debt at fair value, collateralized by loans held for investment, as of December 31, 2017 and December 31, 2016 follows: December 31, 2017 December 31, 2016 Significant Inputs Significant Inputs Weighted Average Discount Rate CPR Range CDR Range Loss Severity Range Weighted Average Discount Rate CPR Range CDR Range Loss Severity Range Securitized debt at fair value, collateralized by loans held for investment 4.1% 6% - 15% 0% - 6% 35% - 60% 4.4% 1% - 35% 0% - 30% 35% - 65% All of the significant inputs listed have some degree of market observability, based on the Company’s knowledge of the market, information available to market participants, and use of common market data sources. Collateral default and loss severity projections are in the form of “curves” that are updated quarterly to reflect the Company’s collateral cash flow projections. Methods used to develop these projections conform to industry conventions. The Company uses assumptions it considers its best estimate of future cash flows for each security. Constant Prepayment Rates The prepayment speed specifies the percentage of the collateral balance that is expected to prepay at each point in the future. The prepayment speed is based on factors such as collateral FICO score, loan-to-value ratio, debt-to-income ratio, and vintage on a loan level basis and is scaled up or down to reflect recent collateral-specific prepayment experience as obtained from remittance reports and market data services. Constant Default Rates Default vectors are determined from the current “pipeline” of loans that are more than 30 days delinquent, in foreclosure, bankruptcy, or are REO. These delinquent loans determine the first 30 months of the default curve. Beyond month 30, the default curve transitions to a value that is reflective of a portion of the current delinquency pipeline. Loss Severity The curve generated to reflect the Company’s expected loss severity is based on collateral-specific experience with consideration given to other mitigating collateral characteristics. Characteristics such as seasoning are taken into consideration because severities tend to initially increase on newly originated securities, before beginning to decline as the collateral ages and eventually stabilize. Collateral characteristics such as loan size, loan-to-value, and geographic location of collateral also effect loss severity. Discount Rate The discount rates applied to the expected cash flows to determine fair value are derived from a range of observable prices on securities backed by similar collateral. As the market becomes more or less liquid, the availability of these observable inputs will change. Sensitivity of Significant Inputs – Loans held for investment The Loans held for investment are comprised primarily of loans collateralized by seasoned subprime residential mortgages. Additionally, it includes non-conforming, single family, owner occupied, jumbo, prime residential mortgages. The significant unobservable inputs used to estimate the fair value of the Loans held for investment collateralized by seasoned subprime residential mortgage loans, as of December 31, 2017 and December 31, 2016 include coupon, FICO score at origination, loan-to-value ratios (LTV), owner occupancy status, and property type. A summary of the significant inputs used to estimate the fair value of Loans held for investment collateralized by seasoned subprime mortgages at fair value as of December 31, 2017 and December 31, 2016 follows: December 31, 2017 December 31, 2016 Factor: Coupon Base Rate 4.8% 5.2% Actual 6.9% 7.1% FICO Base Rate 636 632 Actual 627 621 Loan-to-value (LTV) Base Rate 89% 87% Actual 88% 88% Loan Characteristics: Occupancy Owner Occupied 95% 97% Investor 1% 2% Secondary 4% 1% Property Type Single family 87% 86% Manufactured housing 4% 6% Multi-family/mixed use/other 9% 8% The loan factors are generally not observable for the individual loans and the base rates developed by the Company’s internal model are subjective and change as market conditions change. The impact of the loan coupon on the value of the loan is dependent on whether the loan is clean or reperforming. A clean loan, with no history of delinquent payments and a relatively high loan interest rate would result in a higher overall value than a reperforming loan which has a history of delinquency. Similarly, a higher FICO score and a lower LTV ratio results in increases in the fair market value of the loan and a lower FICO score and a higher LTV ratio results in a lower value. Property types also affect the overall loan values. Property types include single family, manufactured housing and multi-family/mixed use and other types of properties. Single family homes represent properties which house only one family unit. Manufactured homes include mobile homes and modular homes. Loan value for properties that are investor or secondary homes have a reduced value as compared to the baseline loan value. Additionally, single family homes will result in an increase to the loan value where manufactured and multi-family/mixed use and other properties will result in a decrease to the loan value, as compared to the baseline. Financial instruments not carried at fair value The following table presents the carrying value and fair value, as described above, of the Company’s financial instruments not carried at fair value on a recurring basis at December 31, 2017 and December 31, 2016 . December 31, 2017 (dollars in thousands) Level in Fair Value Hierarchy Carrying Amount Fair Value Repurchase agreements 2 7,250,452 7,269,193 Securitized debt, collateralized by Non-Agency RMBS 3 205,780 192,259 December 31, 2016 (dollars in thousands) Level in Fair Value Hierarchy Carrying A

Repurchase Agreements

Repurchase Agreements	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Repurchase Agreements	Repurchase Agreements The interest rates of the Company’s repurchase agreements are generally indexed to the one-month, three-month and twelve-month LIBOR rates and re-price accordingly. The repurchase agreements outstanding, weighted average borrowing rates, weighted average remaining maturities, average daily balances and the fair value of collateral pledged as of December 31, 2017 and December 31, 2016 were: December 31, 2017 December 31, 2016 Repurchase agreements outstanding secured by: Agency MBS (in thousands) $ 3,202,056 $ 3,087,734 Non-agency MBS and Loans held for investment (in thousands) 4,048,396 2,513,169 Total: $ 7,250,452 $ 5,600,903 Average balance of Repurchase agreements secured by: Agency MBS (in thousands) $ 3,120,474 $ 4,159,651 Non-agency MBS and Loans held for investment (in thousands) 3,203,700 2,322,683 Total: $ 6,324,174 $ 6,482,334 Average borrowing rate of Repurchase agreements secured by: Agency MBS 1.47 % 0.90 % Non-agency MBS and Loans held for investment 3.41 % 3.05 % Average remaining maturity of Repurchase agreements secured by: Agency MBS 28 Days 32 Days Non-agency MBS and Loans held for investment 93 Days 98 Days Average original maturity of Repurchase agreements secured by: Agency MBS 87 Days 112 Days Non-agency MBS and Loans held for investment 123 Days 155 Days MBS pledged as collateral at fair value on Repurchase agreements: Agency MBS (in thousands) $ 3,450,123 $ 3,334,245 Non-agency MBS and Loans held for investment (in thousands) 5,338,557 3,699,621 Total: $ 8,788,680 $ 7,033,866 At December 31, 2017 and December 31, 2016 , the repurchase agreements collateralized by MBS and Loans held for investment had the following remaining maturities. December 31, 2017 December 31, 2016 (dollars in thousands) Overnight $ — $ — 1 to 29 days 4,745,342 2,947,604 30 to 59 days 1,206,769 958,956 60 to 89 days 592,865 407,625 90 to 119 days — 559,533 Greater than or equal to 120 days 705,476 727,185 Total $ 7,250,452 $ 5,600,903 At December 31, 2017 , the Company had an amount at risk with Credit Suisse of 12% of its equity related to the collateral posted on repurchase agreements. As of December 31, 2017 the weighted average remaining maturity of the repurchase agreements with Credit Suisse was 25 days and the amount at risk was $451 million . At December 31, 2016 , the Company had an amount at risk with Nomura Securities Company Limited of 10% of its equity related to the collateral posted on repurchase agreements. As of December 31, 2016 , the weighted average maturity of the repurchase agreements with Nomura Securities Company Limited was 104 days and the amount at risk was $320 million . There were no other amounts at risk with any other counterparties greater than 10% of the Company’s equity as of December 31, 2017 and December 31, 2016 .

Securitized Debt

Securitized Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Securitized Debt	Securitized Debt All of the Company’s securitized debt is collateralized by residential mortgage loans or Non-Agency RMBS. For financial reporting purposes, the Company’s securitized debt is accounted for as secured borrowings. Thus, the residential mortgage loans or RMBS held as collateral are recorded in the assets of the Company as Loans held for investment or Non-Agency RMBS and the securitized debt is recorded as a non-recourse liability in the accompanying Consolidated Statements of Financial Condition. Securitized Debt Collateralized by Non-Agency RMBS At December 31, 2017 and December 31, 2016 the Company’s securitized debt collateralized by Non-Agency RMBS is carried at amortized cost and had a principal balance of $219 million and $350 million , respectively. At December 31, 2017 and December 31, 2016 , the debt carried a weighted average cost of financing equal to 6.2% and 5.2% , respectively. The debt matures between the years 2035 and 2047 . None of the Company’s securitized debt collateralized by Non-Agency RMBS is callable. During the year ended December 31, 2017 , the Company acquired securitized debt collateralized by Non-Agency RMBS with an amortized cost balance of $166 thousand for $167 thousand . This transaction resulted in a net loss on the extinguishment of debt of $1 thousand , which is reflected in earnings for the year ended December 31, 2017 . During the year ended December 31, 2016 , the Company acquired securitized debt collateralized by Non-Agency RMBS with an amortized cost balance of $10 million for $11 million . This transaction resulted in a net loss on the extinguishment of debt of $355 thousand . This loss is reflected in earnings for the year ended December 31, 2016 . The following table presents the estimated principal repayment schedule of the securitized debt collateralized by Non-Agency RMBS at December 31, 2017 and December 31, 2016 , based on expected cash flows of the residential mortgage loans or RMBS, as adjusted for projected losses on the underlying collateral of the debt. All of the securitized debt recorded in the Company’s Consolidated Statements of Financial Condition is non-recourse to the Company. December 31, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 42,217 $ 98,565 One to Three Years 45,916 82,563 Three to Five Years 16,524 23,854 Greater Than Five Years 4,867 31,973 Total $ 109,524 $ 236,955 Maturities of the Company’s securitized debt collateralized by Non-Agency RMBS are dependent upon cash flows received from the underlying loans. The estimate of their repayment is based on scheduled principal payments on the underlying loans. This estimate will differ from actual amounts to the extent prepayments or loan losses are experienced. See Note 3 for a more detailed discussion of the securities collateralizing the securitized debt. Securitized Debt Collateralized by Loans Held for Investment At December 31, 2017 and December 31, 2016 the Company’s securitized debt collateralized by loans held for investment had a principal balance of $9.4 billion and $7.1 billion , respectively. At December 31, 2017 and December 31, 2016 the total securitized debt collateralized by loans held for investment carried a weighted average cost of financing equal to 4.2% and 4.0% respectively. As at December 31, 2017 , the maturities of the debt ranges between the years 2023 and 2067 . The debt maturity ranges as at December 31, 2016 were between the years 2021 and 2065. During the year ended December 31, 2017 , the Company acquired securitized debt collateralized by loans with an amortized cost balance of $1.0 billion for $1.1 billion . These transactions resulted in a net loss on the extinguishment of debt of $35 million , which is reflected in earnings for the year ended December 31, 2017 . As the Company's securitized debt is carried at fair value with changes in fair value reflected in earnings, some of this loss was recognized during prior periods. During the year ended December 31, 2016 , the Company acquired securitized debt collateralized by loans with an amortized cost balance of $609 million for $609 million . These transactions resulted in a net loss on the extinguishment of debt of $122 thousand . This loss is reflected in earnings for the year ended December 31, 2016 . The following table presents the estimated principal repayment schedule of the securitized debt collateralized by loans held for investment at December 31, 2017 and December 31, 2016 , based on expected cash flows of the residential mortgage loans or RMBS, as adjusted for projected losses on the underlying collateral of the debt. All of the securitized debt recorded in the Company’s Consolidated Statements of Financial Condition is non-recourse to the Company. December 31, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 1,819,018 $ 1,151,519 One to Three Years 2,872,572 1,841,808 Three to Five Years 2,140,434 1,423,706 Greater Than Five Years 2,439,872 2,477,123 Total $ 9,271,896 $ 6,894,156 Maturities of the Company’s securitized debt collateralized by loans held for investment are dependent upon cash flows received from the underlying loans. The estimate of their repayment is based on scheduled principal payments on the underlying loans. This estimate will differ from actual amounts to the extent prepayments or loan losses are experienced. See Note 4 for a more detailed discussion of the loans collateralizing the securitized debt. Certain of the securitized debt collateralized by loans held for investment contain call provisions and are callable at par, at the option of the Company. The following table presents the par value of the callable debt by year at December 31, 2017 . December 31, 2017 (dollars in thousands) Year Principal 2018 $ 943,573 2019 397,734 2020 4,744,768 2021 2,811,850 2022 287,157 Total $ 9,185,082

Consolidated Securitization Veh

Consolidated Securitization Vehicles and Other Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidated Securitization Vehicles and Other Variable Interest Entities	Consolidated Securitization Vehicles and Other Variable Interest Entities Since its inception, the Company has utilized VIEs for the purpose of securitizing whole mortgage loans or re-securitizing RMBS and obtaining long-term, non-recourse financing. The Company evaluated its interest in each VIE to determine if it is the primary beneficiary. As of December 31, 2017 , the Company’s Consolidated Statement of Financial Condition includes assets of consolidated VIEs with a carrying value of $15.0 billion and liabilities with a carrying value of $9.6 billion . As of December 31, 2016 , the Company’s Consolidated Statement of Financial Condition includes assets of consolidated VIEs with a carrying value of $10.8 billion of and liabilities with a carrying value of $7.3 billion . During the year ended December 31, 2017 , the Company consolidated approximately $7.4 billion unpaid principal balance (excluding $509 million of loans held by a subsidiary of the Company) of seasoned residential subprime mortgage loans. The Company generally sells these loans to multiple real estate mortgage investment conduit trusts (the “Trusts”). The Company purchased certain subordinate notes and trust certificates of the Trusts. The Company evaluated the Trusts and determined that the total equity investment at risk is not sufficient to permit these trusts to finance its activities without additional subordinated financial support provided by another party. Therefore, the Company concluded that the Trusts were VIEs. The Company further determined that their interests in the Trusts gave the Company the power to direct the activity of these VIEs that most significantly impacted the Company's economic performance of the VIEs. As the Company concluded that it was the primary beneficiary of the Trusts, the Company consolidated the assets and liabilities of the Trusts. All intercompany balances and transactions are eliminated in consolidation. The consolidation of these Trusts resulted in the addition of the following amounts, net of eliminations, at the time of securitization. Consolidated Trusts (dollars in thousands) Assets: Loans held for investment, at fair value $ 7,407,677 Other Assets 51,711 Liabilities: Securitized debt at fair value (1) $ 5,188,457 (1) After the elimination of intercompany balances. As sponsor of the Trusts, the Company has retained an eligible horizontal retained interest consisting of the Class B and Class C notes in the Trusts in order to satisfy the U.S. risk retention rules (the “Required Credit Risk”). The U.S. risk retention rules impose limitations on the ability of the Company to dispose of or hedge the Required Credit Risk until the later of (i) the fifth anniversary of the closing date of the securitization transactions (the “Closing Date”) and (ii) the date on which the aggregate unpaid principal balance of the mortgage loans has been reduced to 25% of the aggregate unpaid principal balance of the mortgage loans as of the Closing Date, but in any event no longer than the seventh anniversary of the Closing Date. These investments have been eliminated in consolidation of the Trusts as of December 31, 2017 . VIEs for Which the Company is the Primary Beneficiary The retained beneficial interests in VIEs for which the Company is the primary beneficiary are typically the subordinated tranches of these re-securitizations and in some cases the Company may hold interests in additional tranches. The table below reflects the assets and liabilities recorded in the Consolidated Statements of Financial Condition related to the consolidated VIEs as of December 31, 2017 and December 31, 2016 . December 31, 2017 December 31, 2016 (dollars in thousands) Assets: Non-Agency RMBS, at fair value $ 1,579,793 $ 1,842,080 Loans held for investment, at fair value 13,263,338 8,753,653 Accrued interest receivable 75,489 57,153 Other assets 68,844 109,068 Liabilities: Securitized debt, collateralized by Non-Agency RMBS $ 205,780 $ 334,124 Securitized debt at fair value, collateralized by loans held for investment 9,388,657 6,941,097 Accrued interest payable 33,870 24,942 Other liabilities 3,513 2,742 Income, OTTI and expense amounts related to consolidated VIEs recorded in the Consolidated Statements of Operations is presented in the tables below. For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Interest income, Assets of consolidated VIEs $ 914,022 $ 678,623 $ 575,715 Interest expense, Non-recourse liabilities of VIEs 390,858 249,708 191,922 Net interest income $ 523,164 $ 428,915 $ 383,793 Total other-than-temporary impairment losses $ (2,174 ) $ (1,274 ) $ (2,066 ) Portion of loss recognized in other comprehensive income (loss) (51,118 ) (37,475 ) (55,552 ) Net other-than-temporary credit impairment losses $ (53,292 ) $ (38,749 ) $ (57,618 ) Servicing fees $ 41,493 $ 31,178 $ 25,244 VIEs for Which the Company is Not the Primary Beneficiary The Company is not required to consolidate VIEs in which it has concluded it does not have a controlling financial interest, and thus is not the primary beneficiary. In such cases, the Company does not have both the power to direct the entities’ most significant activities and the obligation to absorb losses or right to receive benefits that could potentially be significant to the VIEs. The Company’s investments in these unconsolidated VIEs are carried in Non-Agency RMBS on the Consolidated Statements of Financial Condition and include senior and subordinated bonds issued by the VIEs. The fair value of the Company’s investments in each unconsolidated VIEs at December 31, 2017 , ranged from less than $1 million to $52 million , with an aggregate amount of $1.3 billion . The fair value of the Company’s investments in each unconsolidated VIEs at December 31, 2016 , ranged from less than $1 million to $51 million , with an aggregate amount of $1.5 billion . The Company’s maximum exposure to loss from these unconsolidated VIEs was $1.2 billion and $1.4 billion at December 31, 2017 and December 31, 2016 , respectively. The maximum exposure to loss was determined as the amortized cost of the unconsolidated VIE, which represents the purchase price of the investment adjusted by any unamortized premiums or discounts as of the reporting date.

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments In connection with the Company’s interest rate risk management strategy, the Company economically hedges a portion of its interest rate risk by entering into derivative financial instrument contracts in the form of interest rate swaps, swaptions, and Treasury futures. The Company’s swaps are used to lock in a fixed rate related to a portion of its current and anticipated payments on its repurchase agreements. The Company typically agrees to pay a fixed rate of interest (“pay rate”) in exchange for the right to receive a floating rate of interest (“receive rate”) over a specified period of time. Treasury futures are derivatives which track the prices of specific Treasury securities and are traded on an active exchange. It is generally the Company’s policy to close out any Treasury futures positions prior to taking delivery of the underlying security. The Company uses Treasury futures to lock in a fixed rate related to a portion of its current and anticipated payments on its repurchase agreements. The use of derivatives creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. In the event of a default by the counterparty, the Company could have difficulty obtaining its RMBS or cash pledged as collateral for these derivative instruments. The Company periodically monitors the credit profiles of its counterparties to determine if it is exposed to counterparty credit risk. See Note 14 for further discussion of counterparty credit risk. The table below summarizes the location and fair value of the derivatives reported in the Consolidated Statements of Financial Condition after counterparty netting and posting of cash collateral as of December 31, 2017 and December 31, 2016 . December 31, 2017 Derivative Assets Derivative Liabilities Derivative Instruments Notional Amount Outstanding Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value (dollars in thousands) Interest Rate Swaps $ 3,816,400 Derivatives, at fair value, net $ 43,257 Derivatives, at fair value, net $ — Swaptions 391,000 Derivatives, at fair value, net 2,105 Derivatives, at fair value, net (320 ) Treasury Futures 619,700 Derivatives, at fair value, net 3,552 Derivatives, at fair value, net — Total $ 4,827,100 $ 48,914 $ (320 ) December 31, 2016 Derivative Assets Derivative Liabilities Derivative Instruments Notional Amount Outstanding Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value (dollars in thousands) Interest Rate Swaps $ 1,396,900 Derivatives, at fair value, net $ — Derivatives, at fair value, net $ — Swaptions 624,000 Derivatives, at fair value, net 7,892 Derivatives, at fair value, net (2,350 ) Treasury Futures 619,700 Derivatives, at fair value, net 1,785 Derivatives, at fair value, net — Total $ 2,640,600 $ 9,677 $ (2,350 ) The effect of the Company’s derivatives on the Consolidated Statements of Operations is presented below. Net gains (losses) on derivatives Derivative Instruments Location on Consolidated Statements of December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Interest Rate Swaps Net unrealized gains (losses) on derivatives $ 43,697 $ 47,170 $ 64,819 Interest Rate Swaps Net realized gains (losses) on derivatives (1) (31,593 ) (88,722 ) (146,173 ) Mortgage Options Net unrealized gains (losses) on derivatives — — 225 Mortgage Options Net realized gains (losses) on derivatives — — 443 Treasury Futures Net unrealized gains (losses) on derivatives 1,768 378 8,634 Treasury Futures Net realized gains (losses) on derivatives (4,061 ) (9,170 ) (35,523 ) Swaptions Net unrealized gains (losses) on derivatives 2,511 2,545 (6,294 ) Swaptions Net realized gains (losses) on derivatives (6,134 ) (7,044 ) (353 ) Other Derivative Assets Net unrealized gains (losses) on derivatives — — — Other Derivative Assets Net realized gains (losses) on derivatives — (566 ) (415 ) Total $ 6,188 $ (55,409 ) $ (114,637 ) (1) Includes loss on termination of interest rate swap of $16 million , $61 million , and $99 million for the years ended December 31, 2017 , 2016 , and 2015 respectively. The Company paid $16 million to terminate interest rate swaps with a notional value of $250 million during the year ended December 31, 2017 . The terminated swaps had original maturities ranging from 2024 to 2034. The Company paid $61 million to terminate interest rate swaps with a notional value of $3.3 billion during the year ended December 31, 2016 . The terminated swaps had original maturities ranging from 2017 to 2034. These amounts represented the fair value of the terminated interest rate swaps, not counting any accrued interest at the time of settlement. The weighted average pay rate on the Company’s interest rate swaps at December 31, 2017 was 1.93% and the weighted average receive rate was 1.53% . The weighted average pay rate on the Company’s interest rate swaps at December 31, 2016 was 2.13% and the weighted average receive rate was 0.90% . The weighted average maturity on the Company’s interest rate swaps at December 31, 2017 and December 31, 2016 was 5 years and 8 years , respectively. Certain of the Company’s derivative contracts are subject to International Swaps and Derivatives Association Master Agreements or other similar agreements which may contain provisions that grant counterparties certain rights with respect to the applicable agreement upon the occurrence of certain events such as (i) a decline in stockholders’ equity in excess of specified thresholds or dollar amounts over set periods of time, (ii) the Company’s failure to maintain its REIT status, (iii) the Company’s failure to comply with limits on the amount of leverage, and (iv) the Company’s stock being delisted from the New York Stock Exchange (NYSE). Upon the occurrence of any one of items (i) through (iv), or another default under the agreement, the counterparty to the applicable agreement has a right to terminate the agreement in accordance with its provisions. Certain of the Company’s interest rate swaps are cleared through a registered commodities exchange. Each of the Company’s ISDAs and clearing exchange agreements contains provisions under which the Company is required to fully collateralize its obligations under the interest rate swap agreements if at any point the fair value of the swap represents a liability greater than the minimum transfer amount contained within the agreements. The Company is also required to post initial collateral upon execution of certain of its swap transactions. If the Company breaches any of these provisions, it will be required to settle its obligations under the agreements at their termination values, which approximates fair value. The Company uses clearing exchange market prices to determine the fair value of its interest rate swaps. The aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a net asset position at December 31, 2017 is approximately $37 million including accrued interest, which represents the maximum amount the Company would receive upon termination, which is fully collateralized.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Capital Stock	Capital Stock Preferred Stock In February 2017, the Company issued 13,000,000 shares of 8.00% Series B Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock, par value $0.01 per share (the “Series B Preferred Stock”), at a public offering price of $25.00 per share. The Series B Preferred Stock is redeemable at $25.00 per share plus accrued and unpaid dividends (whether or not authorized or declared) exclusively at the Company’s option commencing in March 30, 2024, subject to the Company’s right, under limited circumstances, to redeem the Series B Preferred Stock prior to that date. The initial dividend rate for the Series B Preferred Stock, from and including February 27, 2017, to but not including March 30, 2024, will be equal to 8.00% per annum of the $25.00 liquidation preference per share (equivalent to the fixed annual rate of $2.00 per share). On and after March 30, 2024, dividends on the Series B Preferred Stock will accumulate at a percentage of the $25.00 liquidation preference equal to an annual floating rate of the three-month LIBOR plus a spread of 5.791% per annum. The Series B Preferred Stock is entitled to receive, when and as declared, a dividend at a rate of 8.0% per year on the $25.00 liquidation preference before the common stock is paid any dividends and is senior to the common stock with respect to distributions upon liquidation, dissolution or winding up. This transaction was completed in February 2017, pursuant to which the Company received proceeds, net of offering costs, of $314 million . The Company declared dividends to Series B preferred stockholders of $22 million , or $1.68 per preferred share during the year ended December 31, 2017 . In October 2016, the Company issued 5,800,000 shares of 8.00% Series A Cumulative Redeemable Preferred Stock, par value $0.01 per share (the “Series A Preferred Stock”), at a public offering price of $25.00 per share. The Series A Preferred Stock is redeemable at $25.00 per share plus accrued and unpaid dividends (whether or not authorized or declared) exclusively at the Company’s option commencing in October 30, 2021, subject to the Company’s right, under limited circumstances, to redeem the Series A Preferred Stock prior to that date. The Series A Preferred Stock is entitled to receive, when and as declared, a dividend at a rate of 8.0% per year on the $25.00 liquidation preference before the common stock is paid any dividends and is senior to the common stock with respect to distributions upon liquidation, dissolution or winding up. This transaction was completed in October 2016, pursuant to which the Company received proceeds, net of offering costs, of $140 million . The Company declared dividends to Series A preferred stockholders of $12 million , or $2.00 per preferred share during the year ended December 31, 2017 . Common Stock In August 2015, our Board of Directors adopted a share repurchase program (the “Repurchase Program”) that authorized repurchases of our common stock up to $250 million . In February 2016, our Board of Directors increased the Repurchase Program by $100 million . In February 2018, our Board of Directors reauthorized the $100 million available under the Repurchase Program. Such authorization does not have an expiration date and, at present, there is no intention to modify or otherwise rescind such authorization. Shares of our common stock may be purchased in the open market, including through block purchases, through privately negotiated transactions, or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The timing, manner, price and amount of any repurchases will be determined at our discretion and the program may be suspended, terminated or modified at any time for any reason. Among other factors, the Company intends to only consider repurchasing shares of our common stock when the purchase price is less than its estimate of its current book value per common share. In addition, the Company does not intend to repurchase any shares from directors, officers or other affiliates. The program does not obligate the Company to acquire any specific number of shares, and all repurchases will be made in accordance with Rule 10b-18, which sets certain restrictions on the method, timing, price and volume of stock repurchases. The Company did no t repurchase any shares during the year ended December 31, 2017 , and has $100 million in the Repurchase Program that may be used to repurchase shares in the future. During the year ended December 31, 2017 , the Company declared regular dividends to common shareholders of $377 million , or $2.00 per share. For the year ended December 31, 2016 , the Company declared regular dividends to common shareholders of $364 million , or $1.94 per share, and a special dividend of $94 million , or $0.50 per share. For the year ended December 31, 2015, the Company declared regular dividends to common shareholders of $379 million , or $1.92 per share. Earnings per share for the years ended December 31, 2017 , 2016 , and 2015 respectively, are computed as follows: For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Numerator: Net income available to common shareholders $ 491,184 $ 549,494 $ 250,349 Effect of dilutive securities: — — — Dilutive net income available to common shareholders $ 491,184 $ 549,494 $ 250,349 Denominator: Weighted average basic shares 187,780,355 187,728,634 199,563,196 Effect of dilutive securities 506,965 296,204 86,981 Weighted average dilutive shares 188,287,320 188,024,838 199,650,177 Net income per average share attributable to common stockholders - Basic $ 2.62 $ 2.93 $ 1.25 Net income per average share attributable to common stockholders - Diluted $ 2.61 $ 2.92 $ 1.25

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income The following table presents the changes in the components of Accumulated Other Comprehensive Income (“AOCI”) for the year ended December 31, 2017 and 2016 : December 31, 2017 (dollars in thousands) Unrealized gains (losses) on available-for-sale securities, net Total Accumulated OCI Balance Balance as of December 31, 2016 $ 718,106 $ 718,106 OCI before reclassifications 24,218 24,218 Amounts reclassified from AOCI 54,578 54,578 Net current period OCI 78,796 78,796 Balance as of December 31, 2017 $ 796,902 $ 796,902 December 31, 2016 (dollars in thousands) Unrealized gains (losses) on available-for-sale securities, net Total Accumulated OCI Balance Balance as of December 31, 2015 $ 773,791 $ 773,791 OCI before reclassifications (88,527 ) (88,527 ) Amounts reclassified from AOCI 32,842 32,842 Net current period OCI (55,685 ) (55,685 ) Balance as of December 31, 2016 $ 718,106 $ 718,106 The following table presents the details of the reclassifications from AOCI for the year ended December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 Details about Accumulated OCI Components Amounts Reclassified from Accumulated OCI Amounts Reclassified from Accumulated OCI Affected Line on the Consolidated Statements Of Operations Unrealized gains and losses on available-for-sale securities $ 7,278 $ 25,145 Net realized gains (losses) on sales of investments (61,856 ) (57,987 ) Net other-than-temporary credit impairment losses $ (54,578 ) $ (32,842 ) Income before income taxes — — Income taxes $ (54,578 ) $ (32,842 ) Net of tax

Equity Compensation, Employment

Equity Compensation, Employment Agreements and other Benefit Plans	12 Months Ended
	Dec. 31, 2017
Compensation Related Costs [Abstract]
Equity Compensation, Employment Agreements and other Benefit Plans	Equity Compensation, Employment Agreements and other Benefit Plans In accordance with the terms of the Company’s 2007 Equity Incentive Plan (as amended and restated on December 10, 2015) (the “Incentive Plan”), directors, officers and employees of the Company are eligible to receive restricted stock grants. These awards generally have a restriction period lasting between three and ten years depending on the award, after which time the awards fully vest. During the vesting period, these shares may not be sold. There were approximately 6 million shares available for future grants under the Incentive Plan as of December 31, 2017 . During the first quarter of 2016 , the Compensation Committee of the Board of Directors of the Company approved a Stock Award Deferral Program (the “Deferral Program”). Under the Deferral Program, non-employee directors and certain executive officers can elect to defer payment of certain stock awards made pursuant to the Equity Plan. Deferred awards are treated as deferred stock units and paid at the earlier of separation from service or a date elected by the participant. Payments are generally made in a lump sum or, if elected by the participant, in five annual installments. Deferred awards receive dividend equivalents during the deferral period in the form of additional deferred stock units. Amounts are paid at the end of the deferral period by delivery of shares from the Incentive Plan (plus cash for any fractional deferred stock units), less any applicable tax withholdings. Deferral elections do not alter any vesting requirements applicable to the underlying stock award. During the year ended December 31, 2017 and 2016 , the Company granted certain of its employees Restricted Stock Units (“RSU”) awards. RSU awards are designed to reward certain employees of the Company for services provided over the previous year. The RSU awards vest equally over a three -year period beginning from the grant date and will fully vest after three years . The RSU awards are valued at the market price of the Company’s common stock on the grant date and the employees must be employed by the Company on the vesting dates to receive the RSU awards. The Company granted 204 thousand and 360 thousand RSU awards during the year ended December 31, 2017 and 2016 , with a grant date fair value of $4 million and $5 million , respectively, which will be recognized as compensation expense on a straight-line basis over the three year vesting period. During the year ended December 31, 2017 and 2016 , the Company granted certain of its employees 144 thousand and 180 thousand Performance Share Units (“PSU”) awards, respectively. PSU awards are designed to align compensation with the Company’s future performance. The PSU awards include a three year performance period ending on December 31, 2019 and December 31, 2018 , respectively. The final number of shares that will vest will be between 0% to 150% of the total PSU awards granted based on the stock performance of the Company as compared to an index of comparable financial institutions and will cliff vest at the end of the performance period. The PSU awards are measured at fair value on the grant date which will be recognized as compensation expense ratably over the three -year vesting period. Fair value is determined using a Monte Carlo valuation model developed to value the specific features of the PSU awards, including market based conditions. Inputs into the model include the Company’s historical volatility, the peer average historical volatility, and the correlation coefficient of the volatility. In addition, inputs also included the share price at the beginning of the measurement period and an estimated total shareholder return for both the Company and the peer group of comparable financial institutions. Based on the model results, the 144 thousand PSU awards granted during 2017 had a grant date value of $3 million that will cliff vest on December 31, 2019. The 180 thousand PSU awards granted during 2016 had a grant date value of $3 million which will cliff vest on December 31, 2018. The following table presents information with respect to the Company's stock awards during the years ended December 31, 2017 and 2016 . For the Year Ended December 31, 2017 December 31, 2016 Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Unvested shares outstanding - beginning of period 577,547 14.53 71,000 28.39 Granted 348,244 18.68 539,847 13.49 Vested (155,976 ) 30.74 (33,300 ) 27.23 Forfeited — — — — Unvested shares outstanding - end of period 769,815 25.58 577,547 14.53 The Company recognized stock based compensation expenses of $4 million , $2 million and $1 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company also maintains a qualified 401(k) plan. The plan is a retirement savings plan that allows eligible employees to contribute a portion of their wages on a tax-deferred basis under Section 401(k) of the Code. Employees may contribute, through payroll deductions, up to $18,000 if under the age of 50 years and an additional $6,000 “catch-up” contribution for employees 50 years or older. The Company matches 100% of the first 6% of the eligible compensation deferred by employee contributions. The employer funds the 401(k) matching contributions in the form of cash, and participants may direct the Company match to an investment of their choice. The benefit of the Company’s contributions vests immediately. Generally, a participating employee is entitled to distributions from the plans upon termination of employment, retirement, death or disability. The 401(k) expense related to the Company’s qualified plan for the years ended December 31, 2017 , 2016 and 2015 was $376 thousand , $335 thousand and $82 thousand , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the years ended December 31, 2017 and 2016 , the Company qualified to be taxed as a REIT under Code Sections 856 through 860. As a REIT, the Company is not subject to federal income tax to the extent that it makes qualifying distributions of taxable income to its stockholders. To maintain qualification as a REIT, the Company must distribute at least 90% of its annual REIT taxable income to its shareholders and meet certain other requirements such as assets it may hold, income it may generate and its shareholder composition. It is generally the Company’s policy to distribute to its shareholders all of the Company’s taxable income. The state and local tax jurisdictions to which the Company is subject to tax-filing obligations, recognize the Company’s status as a REIT, and therefore, the Company generally does not pay income tax in such jurisdictions. The Company may, however, be subject to certain minimum state and local tax filing fees and its TRSs are subject to federal, state and local taxes. There were no significant income tax expenses for the years ended December 31, 2017 , 2016 , and 2015 . On December 22, 2017, H.R.1, informally known as the Tax Cuts and Jobs Act (the "TCJA"), was enacted that included, among other items, a reduction in the U.S. federal corporate income tax rate from 35% to 21% effective January 1, 2018. Under generally accepted accounting principles, the Company is required to recognize the effect of this rate change in its deferred tax assets and liabilities in the period the tax rate change is enacted. The Company recorded a deferred tax asset of $4 million and $5 million for the years ended December 31, 2017 and 2016 , respectively, relating to activities of its TRSs. Of these amounts, the amount related to cumulative net operating losses was $1 million and $2 million as of December 31, 2017 and 2016 , respectively, and the amount related to losses which were disallowed under Code Section 267(a) was $3 million as of December 31, 2017 and 2016 . The Company evaluates, based on both positive and negative evidence, the likelihood of realizing its deferred tax assets and established a valuation allowance of $4 million and $5 million for the years ended December 31, 2017 and 2016 . We continue to analyze and monitor the application of TCJA to our business. In general, cash dividends declared by the Company will be considered ordinary income to stockholders for income tax purposes. From time to time, a portion of the Company’s dividends may be characterized as capital gains or return of capital distributions. The Company’s effective tax rate differs from its combined federal, state and city corporate statutory tax rate primarily due to the deduction of dividend distributions required to be paid under Code Section 857(a). The Company’s 2016, 2015 and 2014 federal, state and local tax returns remain open for examination.

Credit Risk and Interest Rate R

Credit Risk and Interest Rate Risk	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Credit Risk and Interest Rate Risk	Credit Risk and Interest Rate Risk The Company’s primary components of market risk are credit risk and interest rate risk. The Company is subject to interest rate risk in connection with its investments in Agency MBS and Non-Agency RMBS, residential mortgage loans, borrowings under repurchase agreements and securitized debt. When the Company assumes interest rate risk, it attempts to minimize interest rate risk through asset selection, hedging and matching the income earned on mortgage assets with the cost of related financing. The Company attempts to minimize credit risk through due diligence, asset selection and portfolio monitoring. The Company has established a whole loan target market including prime and subprime borrowers, Alt-A documentation, geographic diversification, owner-occupied property, and moderate loan-to-value ratios. These factors are considered to be important indicators of credit risk. By using derivative instruments and repurchase agreements, the Company is exposed to counterparty credit risk if counterparties to the contracts do not perform as expected. If a counterparty fails to perform on a derivative hedging instrument, the Company’s counterparty credit risk is equal to the amount reported as a derivative asset on its balance sheet to the extent that amount exceeds collateral obtained from the counterparty or, if in a net liability position, the extent to which collateral posted exceeds the liability to the counterparty. The amounts reported as a derivative asset/(liability) are derivative contracts in a gain/(loss) position, and to the extent subject to master netting arrangements, net of derivatives in a loss/(gain) position with the same counterparty and collateral received/(pledged). If the counterparty fails to perform on a repurchase agreement, the Company is exposed to a loss to the extent that the fair value of collateral pledged exceeds the liability to the counterparty. The Company attempts to minimize counterparty credit risk by evaluating and monitoring the counterparty’s credit, executing master netting arrangements and obtaining collateral, and executing contracts and agreements with multiple counterparties to reduce exposure to a single counterparty. Our repurchase agreements and derivative transactions are governed by underlying agreements that provide for a right of setoff under master netting arrangements, including in the event of default or in the event of bankruptcy of either party to the transactions. The Company presents its assets and liabilities subject to such arrangements on a net basis in our consolidated statements of financial condition. The following table presents information about our liabilities that are subject to such arrangements and can potentially be offset on our consolidated statements of financial condition as of December 31, 2017 and December 31, 2016 . December 31, 2017 (dollars in thousands) Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts Offset in the Consolidated Statements of Financial Position Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position Financial Instruments Cash Collateral (Received) Pledged (1) Net Amount Repurchase Agreements $ (7,250,452 ) $ — $ (7,250,452 ) $ 8,788,680 $ 1,156 $ 1,539,384 Interest Rate Swaps - Gross Assets 44,874 (1,617 ) 43,257 — 11,570 54,827 Interest Rate Swaps - Gross Liabilities (1,617 ) 1,617 — — — — Treasury Futures - Gross Assets 3,552 — 3,552 — 376 3,928 Treasury Futures - Gross Liabilities — — — — — — Swaptions - Gross Assets 2,105 — 2,105 — — 2,105 Swaptions - Gross Liabilities (320 ) — (320 ) — — (320 ) Total Liabilities $ (7,201,858 ) $ — $ (7,201,858 ) $ 8,788,680 $ 13,102 $ 1,599,924 (1) Included in other assets December 31, 2016 (dollars in thousands) Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts Offset in the Consolidated Statements of Financial Position Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position Financial Instruments Cash Collateral (Received) Pledged (1) Net Amount Repurchase Agreements $ (5,600,903 ) $ — $ (5,600,903 ) $ 7,033,866 $ 2,545 $ 1,435,508 Interest Rate Swaps - Gross Assets 14,435 (14,435 ) — — — — Interest Rate Swaps - Gross Liabilities (14,875 ) 14,875 — — 39,627 39,627 Treasury Futures - Gross Assets 1,785 — 1,785 — 3,320 5,105 Treasury Futures - Gross Liabilities — — — — — — Swaptions - Gross Assets 7,892 — 7,892 — — 7,892 Swaptions - Gross Liabilities (2,350 ) — (2,350 ) 10,341 — 7,991 Total Liabilities $ (5,594,016 ) $ 440 $ (5,593,576 ) $ 7,044,207 $ 45,492 $ 1,496,123 (1) Included in other assets

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time, the Company may become involved in various claims and legal actions arising in the ordinary course of business. In connection with certain re-securitization transactions engaged in by the Company, it has the obligation under certain circumstances to repurchase assets from the VIE upon breach of certain representations and warranties.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events None.

Summarized Quarterly Results (U

Summarized Quarterly Results (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summarized Quarterly Results (Unaudited)	Summarized Quarterly Results (Unaudited) The following is a presentation of the results of operations for the quarters ended December 31, 2017, September 30, 2017, June 30, 2017 and March 31, 2017. For the Quarter Ended December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 (dollars in thousands, except per share data) Net Interest Income: Interest income $ 301,957 $ 296,813 $ 288,644 $ 251,344 Interest expense 144,204 140,358 137,955 110,231 Net interest income 157,753 156,455 150,689 141,113 Other-than-temporary impairments: Total other-than-temporary impairment losses (923 ) (784 ) (749 ) (2,713 ) Portion of loss recognized in other comprehensive income (17,256 ) (10,684 ) (12,760 ) (15,988 ) Net other-than-temporary credit impairment losses (18,179 ) (11,468 ) (13,509 ) (18,701 ) Net gains (losses) on derivatives 31,108 1,363 (21,822 ) (4,462 ) Net unrealized gains (losses) on financial instruments at fair value (47,637 ) 19,042 67,762 72,243 Net realized gains (losses) on sales of investments (586 ) 1 4,541 5,167 Gain (loss) on Extinguishment of Debt 12,742 (1 ) (48,014 ) — Total other expenses 27,657 26,142 24,491 32,537 Net income (loss) $ 107,608 $ 139,232 $ 115,017 $ 162,807 Dividend on preferred stock $ 9,400 $ 9,400 $ 9,400 $ 5,283 Net income (loss) available to common shareholders $ 98,208 $ 129,832 $ 105,617 $ 157,524 Net income per common share-basic $ 0.52 $ 0.69 $ 0.56 $ 0.84 The following is a presentation of the results of operations for the quarters ended December 31, 2016, September 30, 2016, June 30, 2016 and March 31, 2016. For the Quarter Ended December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 (dollars in thousands, except per share data) Net Interest Income: Interest income $ 260,823 $ 250,953 $ 221,096 $ 201,194 Interest expense 106,737 94,911 83,227 62,981 Net interest income 154,086 156,042 137,869 138,213 Other-than-temporary impairments: Total other-than-temporary impairment losses (1,034 ) (993 ) (3,129 ) (4,423 ) Portion of loss recognized in other comprehensive income (13,746 ) (10,581 ) (17,816 ) (6,255 ) Net other-than-temporary credit impairment losses (14,780 ) (11,574 ) (20,955 ) (10,678 ) Net gains (losses) on derivatives 115,523 13,360 (47,755 ) (136,537 ) Net unrealized gains (losses) on financial instruments at fair value (20,664 ) 32,999 30,347 16,871 Net realized gains (losses) on sales of investments 11,121 3,079 6,631 (2,674 ) Gain (loss) on Extinguishment of Debt 1,334 (45 ) — (1,766 ) Other Income — — — 95,000 Total other expenses 24,698 21,031 31,987 15,302 Net income (loss) $ 221,903 $ 172,817 $ 74,127 $ 83,098 Dividend on preferred stock $ 2,449 $ — $ — $ — Net income (loss) available to common shareholders $ 219,454 $ 172,817 $ 74,127 $ 83,098 Net income per common share-basic $ 1.17 $ 0.92 $ 0.39 $ 0.44

Summary of the Significant Ac26

Summary of the Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying consolidated financial statements and related notes of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). In the opinion of management, all adjustments considered necessary for a fair presentation of the Company's financial position, results of operations and cash flows have been included. Certain prior period amounts have been reclassified to conform to the current period's presentation. The consolidated financial statements include, the Company’s accounts, the accounts of its wholly-owned subsidiaries, and variable interest entities (“VIEs”) in which the Company is the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation. The Company uses securitization trusts considered to be VIEs in its securitization and re-securitization transactions. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest, or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary, and is generally the entity with (i) the power to direct the activities that most significantly impact the VIEs’ economic performance, and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. For VIEs that do not have substantial on-going activities, the power to direct the activities that most significantly impact the VIEs’ economic performance may be determined by an entity’s involvement with the design and structure of the VIE. The trusts are structured as pass through entities that receive principal and interest on the underlying collateral and distribute those payments to the security holders. The assets held by the securitization entities are restricted in that they can only be used to fulfill the obligations of the securitization entity. The Company’s risks associated with its involvement with these VIEs are limited to its risks and rights as a holder of the security it has retained. Determining the primary beneficiary of a VIE requires judgment. The Company determined that for the securitizations it consolidates, its ownership provides the Company with the obligation to absorb losses or the right to receive benefits from the VIE that could be significant to the VIE. In addition, the Company has the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance (“power”) such as rights to direct servicer activity or the Company was determined to have power in connection with its involvement with the structure and design of the VIE. The Company’s interest in the assets held by these securitization vehicles, which are consolidated on the Company’s Statements of Financial Condition, is restricted by the structural provisions of these trusts, and a recovery of the Company’s investment in the vehicles will be limited by each entity’s distribution provisions. The liabilities of the securitization vehicles, which are also consolidated on the Company’s Statements of Financial Condition, are non-recourse to the Company, and can only be satisfied from each securitization vehicle’s respective asset pool. The assets of securitization entities are comprised of residential mortgage backed securities (“RMBS”) or residential mortgage loans.
Statements of Financial Condition Presentation	Statements of Financial Condition Presentation The Company’s Consolidated Statements of Financial Condition include both the Company’s direct assets and liabilities and the assets and liabilities of consolidated securitization vehicles. Assets of each consolidated VIE can only be used to satisfy the obligations of that VIE, and the liabilities of consolidated VIEs are non-recourse to the Company. The Company is not obligated to provide, nor does it intend to provide, any financial support to these consolidated securitization vehicles. The notes to the consolidated financial statements describe the Company’s assets and liabilities including the assets and liabilities of consolidated securitization vehicles.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand and cash deposited overnight in money market funds, which are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation.
Agency and Non-Agency Mortgage-Backed Securities	Agency and Non-Agency Mortgage-Backed Securities The Company invests in mortgage backed securities (“MBS”) representing interests in obligations backed by pools of mortgage loans. The Company delineates between Agency MBS and Non-Agency MBS as follows: (1) Agency MBS are mortgage pass-through certificates, collateralized mortgage obligations (“CMOs”), and other MBS representing interests in or obligations backed by pools of mortgage loans issued or guaranteed by agencies of the U.S. Government, such as Ginnie Mae, or federally chartered corporations such as Freddie Mac or Fannie Mae where principal and interest repayments are guaranteed by the respective agency of the U.S. Government or federally chartered corporation; and (2) Non-Agency MBS are not issued or guaranteed by a U.S. Government Agency or other institution and are subject to credit risk. Repayment of principal and interest on Non-Agency MBS is subject to the performance of the mortgage loans or MBS collateralizing the obligation. The Company also invests in Interest Only Agency MBS strips and Interest Only Non-Agency RMBS strips (“IO MBS strips”). IO MBS strips represent the Company’s right to receive a specified proportion of the contractual interest flows of the collateral. Interest income on IO MBS strips is accrued based on the outstanding notional balance and the security’s contractual terms, and amortization of any premium is calculated in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 325-40, Beneficial Interests in Securitized Financial Assets (“ASC 325-40”). The Company accounts for IO MBS strips at fair value with changes in fair value recognized in the Company’s Consolidated Statements of Operations. The Company classifies the majority of its MBS as available-for-sale and records investments at estimated fair value as described in Note 5 of these consolidated financial statements. The Company includes unrealized gains and losses considered to be temporary on certain MBS in Other comprehensive income (“OCI”) in the Consolidated Statements of Operations. For IO MBS strips and certain other MBS investments, the Company carries these investments at fair value with changes in fair value included in earnings in the Consolidated Statements of Operations. From time to time, as part of the overall management of its portfolio, the Company may sell any of its investments and recognize a realized gain or loss as a component of earnings in the Consolidated Statements of Operations utilizing the average cost method. The Company’s accounting policy for interest income and impairment related to its MBS is as follows: Interest Income Recognition The recognition of interest income on MBS securities varies depending on the characteristics of the security as follows: Agency MBS and Non-Agency RMBS of High Credit Quality FASB ASC 310-20, Nonrefundable Fees and Other Costs (“ASC 310-20”) is applied to the recognition of interest income for the following securities: • Certain Agency MBS • Non-Agency RMBS that meet all of the following conditions at the acquisition date (referred to hereafter as “Non-Agency RMBS of High Credit Quality”): 1. Rated AA or higher by a nationally recognized credit rating agency using the lowest rating available; 2. The Company expects to collect all of the security's contractual cash flows; and 3. The security cannot be contractually prepaid such that the Company would not recover substantially all of its recorded investment. Under ASC 310-20, interest income, including premiums and discounts associated with the acquisition of these securities, is recognized over the life of such securities using the interest method based on the contractual cash flows of the security. In applying the interest method, the Company considers estimates of future principal prepayments in the calculation of the effective yield. Differences that arise between previously anticipated prepayments and actual prepayments received, as well as changes in future prepayment assumptions, result in a recalculation of the effective yield on the security. This recalculation of the effective yield is updated on a quarterly basis. Upon a recalculation of the effective yield, the investment in the security is adjusted to the amount that would have existed had the new effective yield been retrospectively applied since acquisition with a corresponding charge or credit to interest income. Non-Agency RMBS Not of High Credit Quality Non-Agency RMBS purchased at a discount and not of high credit quality at the time of purchase are accounted for under ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality (“ASC 310-30”) or ASC 325-40 (referred to hereafter as “Non-Agency RMBS Not of High Credit Quality”). Non-Agency RMBS are accounted for under ASC 310-30 if the following conditions are met as of the acquisition date: 1. There is evidence of deterioration in credit quality of the security from its inception; and 2. It is probable that the Company will be unable to collect all contractual cash flows of the security. Non-Agency RMBS that are not within the scope of ASC 310-30 are accounted for under ASC 325-40 if at the acquisition date: 1. The security is not of high credit quality (defined as rated below AA or is unrated), or 2. The security can contractually be prepaid or otherwise settled in such a way that the Company would not recover substantially all of its recorded investment. Interest income on Non-Agency RMBS Not of High Credit Quality is recognized using the interest method based on management’s estimates of cash flows expected to be collected. The effective interest rate on these securities is based on management’s estimate for each security of the projected cash flows, which are estimated based on observation of current market information and include assumptions related to fluctuations in prepayment speeds and the timing and amount of credit losses. On a quarterly basis, the Company reviews and, if appropriate, makes adjustments to its cash flow projections based on inputs and analyses received from external sources, internal models, and the Company’s judgments about prepayment rates, the timing and amount of credit losses, and other factors. Changes in the amount or timing of cash flows from those originally projected, or from those estimated at the last evaluation date, are considered to be either positive changes or adverse changes. For securities accounted for under ASC 325-40, any positive or adverse change in cash flows that does not result in the recognition of an other-than-temporary impairment (“OTTI”) results in a retrospective increase or decrease in the effective interest rate used to recognize interest income. For securities accounted for under ASC 310-30, only significant positive changes are reflected prospectively in the effective interest rate used to recognize interest income. Under ASC 310-30, adverse changes in cash flows expected to be collected for Non-Agency RMBS, in an unrealized loss position, generally result in recognition of an OTTI with no change in the effective interest rate used to recognize interest income. Impairment Considerations Applicable to certain MBS When the fair value of an available-for-sale MBS is less than its amortized cost, the security is considered impaired. On a quarterly basis, the Company evaluates its securities for OTTI. If the Company intends to sell an impaired security, or it is more-likely-than-not that the Company will be required to sell an impaired security before its anticipated recovery, then the Company must recognize an OTTI through a charge to earnings equal to the entire difference between the investment’s amortized cost and its fair value at the measurement date. If the Company does not intend to sell an impaired security and it is not more-likely-than-not that it would be required to sell an impaired security before recovery, the Company must further evaluate the security for impairment due to credit losses. The credit component of OTTI is recognized in earnings and the remaining component is recorded as a component of OCI. Following the recognition of an OTTI through earnings, a new amortized cost basis is established for the security and subsequent recovery in fair value may not be adjusted through current earnings. Subsequent recoveries are amortized into income over the remaining life of the security as an adjustment to yield. When evaluating whether the Company intends to sell an impaired security or will more-likely-than-not be required to sell an impaired security before recovery, the Company makes judgments that consider among other things, its liquidity, leverage, contractual obligations, and targeted investment strategy to determine its intent and ability to hold the investments that are deemed impaired. The determination as to whether an OTTI exists is based on factual information available at the time of assessment as well as the Company’s estimates of future conditions. As a result, the determination of OTTI and its timing and amount is based on estimates that may change materially over time. The Company’s estimate of the amount and timing of cash flows for its MBS is based on its review of the underlying securities or mortgage loans securing the MBS. The Company considers historical information available and expected future performance of the underlying securities or mortgage loans, including timing of expected future cash flows, prepayment rates, default rates, loss severities, delinquency rates, percentage of non-performing loans, extent of credit support available, Fair Isaac Corporation (“FICO”) scores at loan origination, year of origination, loan-to-value ratios, geographic concentrations, as well as reports by credit rating agencies, current and forecast interest rates, general market assessments and dialogue with market participants. As a result, substantial judgment is used in the Company’s analysis to determine the expected cash flows for its MBS. Considerations Applicable to Non-Agency RMBS of High Credit Quality The impairment assessment for Non-Agency RMBS of High Credit Quality involves comparing the present value of the remaining cash flows expected to be collected to the amortized cost of the security at the assessment date. The discount rate used to calculate the present value of the expected future cash flows is based on the security’s effective interest rate as calculated under ASC 310-20 (i.e., the discount rate implicit in the security as of the last measurement date). If the present value of the remaining cash flows expected to be collected is less than the amortized cost basis, an OTTI is recognized in earnings for the difference. This amount is considered to be the credit loss component; the remaining difference between amortized cost and the fair value of the security is considered to be the portion of loss recognized in other comprehensive income. Considerations Applicable to Non-Agency RMBS Not of High Credit Quality Non-Agency RMBS within the scope of ASC 325-40 or ASC 310-30 are considered other-than-temporarily impaired when the following two conditions exist: (1) the fair value is less than the amortized cost basis, and (2) there has been an adverse change in cash flows expected to be collected from the last measurement date (i.e. adverse changes in either the amount or timing of cash flows from those previously expected). The OTTI is separated into a credit loss component that is recognized in earnings and the portion of loss recognized in other comprehensive income. The credit component is comprised of the impact of the fair value decline due to changes in assumptions related to default (collection) risk and prepayments. The portion of loss recognized in other comprehensive income comprises the change in fair value of the security due to all other factors, including changes in benchmark interest rates and market liquidity. In determining the OTTI related to credit losses for securities, the Company compares the present value of the remaining cash flows adjusted for prepayments expected to be collected at the current financial reporting date to the present value of the remaining cash flows expected to be collected at the original purchase date (or the last date those estimates were revised for accounting purposes). The discount rate used to calculate the present value of expected future cash flows is the effective interest rate used for income recognition purposes as determined under ASC 325-40 or ASC 310-30. The determination of whether an OTTI exists and, if so, the extent of the credit component is subject to significant judgment and management’s estimates of both historical information available at the time of assessment, the current market environment, as well as the Company’s estimates of the future performance and projected amount and timing of cash flows expected to be collected on the security. As a result, the timing and amount of OTTI constitutes an accounting estimate that may change materially over time. Investments for which the Company has elected the fair value option are not evaluated for OTTI as all changes in fair value are reflected in earnings.
Loans Held for Investment	Loans Held for Investment The Company's loans held for investment portfolio is comprised of seasoned residential mortgage loans that are not guaranteed as to repayment of principal or interest. These loans are serviced and may be modified by a third-party servicer. The Company generally has the ability to approve certain loan modifications and determine the course of action to be taken as it relates to certain loans in default, including whether or not to proceed with foreclosure. Additionally, in certain cases, the Company has the ability to remove the servicer with or without cause upon prior notice. These mortgage loans are designated as held for investment. Interest income on loans held for investment is recognized over the expected life of the loans using the interest method with changes in yield reflected in earnings on a prospective basis and are carried at fair value with changes in fair value recorded in earnings. The Company estimates the fair value of securitized loans as described in Note 5 of these consolidated financial statements. Interest is accrued on all loans held for investment when due. Interest which is not received at the due date is written off when it becomes delinquent. Nonrefundable fees and costs related to acquiring the Company’s residential mortgage loans are recognized as expenses in the Consolidated Statements of Operations. Income recognition is suspended for loans when, based on information from the servicer, a full recovery of interest or principal becomes doubtful. Real estate owned Real estate owned (“REO”) represents properties which the Company has received the legal title of the property to satisfy the outstanding loan. REO is re-categorized from loan to REO when the Company takes legal title of the property. REO assets are measured and reported at the estimated fair value less the estimated cost to sell at the end of each reporting period. At the time the asset is re-categorized, any difference between the previously recorded loan balance and the carrying value of the REO at the time the Company takes legal title of the property, is recognized as a loss. All REO assets of the Company are held-for-sale and it is the Company’s intention to sell the property in the shortest time possible to maximize their return and recovery on the previously recorded loan.
Repurchase Agreements	Repurchase Agreements The Company finances the acquisition of a significant portion of its mortgage-backed securities with repurchase agreements. The Company has evaluated each agreement and has determined that each of the repurchase agreements be accounted for as secured borrowings, which is recourse to the Company.
Securitized Debt, collateralized by Non-Agency RMBS and Securitized Debt, collateralized by Loans held for investment	Securitized Debt, collateralized by Non-Agency RMBS and Securitized Debt, collateralized by Loans held for investment Certain re-securitization transactions classified as Securitized Debt, collateralized by Non-Agency RMBS, reflect the transfer to a trust of fixed or adjustable rate MBS which are classified as Non-Agency RMBS that pay interest and principal to the debt holders of that re-securitization. Re-securitization transactions completed by the Company that did not qualify as sales are accounted for as secured borrowings. The associated securitized debt is carried at amortized cost, net of any unamortized premiums or discounts. Certain transactions involving residential mortgage loans are accounted for as secured borrowings, and are recorded as Securitized loans held for investment and the corresponding debt as Securitized debt, collateralized by loans held for investment in the Consolidated Statements of Financial Condition. These securitizations are collateralized by residential adjustable or fixed rate mortgage loans that have been placed in a trust and pay interest and principal to the debt holders of that securitization. The Securitized debt, collateralized by loans held for investment, is carried at fair value. The Company recognizes interest expense on securitized debt over the contractual life of the debt using the interest method with changes in yield reflected in earnings on a retrospective basis. The Company estimates the fair value of its securitized debt as described in Note 5 to these consolidated financial statements.
Fair Value	Loans Held for Investment: The Company’s Loans held for investment are carried at fair value with changes in fair value reflected in earnings. The Company carries Loans held for investment at fair value as it may resecuritize these loans in the future. Additionally, the fair value option allows both the loans and related financing to be consistently reported at fair value and to achieve operational and valuation simplifications. Changes in fair value of Loans held for investment are presented in Net unrealized gains (losses) on financial instruments at fair value on the Consolidated Statements of Operations. Securitized Debt, Collateralized by Loans Held for Investment: The Company’s securitized debt, collateralized by loans held for investment, is carried at fair value with changes in fair value reflected in earnings. The Company has elected the fair value option for these financings as it may call or restructure these debt financings in the future. Additionally, the fair value option allows both the loans and related financing to be consistently reported at fair value and to achieve operational and valuation simplifications. Changes in fair value of securitized debt, collateralized by loans held for investment are presented in Net unrealized gains (losses) on financial instruments at fair value on the Consolidated Statements of Operations. Fair Value Disclosure A complete discussion of the methodology utilized by the Company to estimate the fair value of its financial instruments is included in Note 5 to these consolidated financial statements. Interest-Only MBS: The Company accounts for the IO MBS strips at fair value with changes in fair value reported in earnings. The IO MBS strips are included in MBS, at fair value, on the accompanying Consolidated Statements of Financial Condition. Fair Value Agency MBS: The Company has elected to account for Agency MBS investments acquired on or after July 1, 2017 under the fair value option. Under the fair value option, these investments will be carried at fair value, with changes in fair value reported in earnings (included as part of “Net unrealized gains (losses) on financial instruments at fair value”). Consistent with all other investments for which the Company has elected the fair value option, the Company will recognize revenue on a prospective basis in accordance with guidance in ASC 325-40. All Agency MBS investments owned prior to July 1, 2017 will continue to be carried at fair value with changes in fair value reported in other comprehensive income (OCI) as available-for-sale investments. All revenue recognition for these Agency MBS investments owned prior to July 1, 2017 will be in accordance with ASC 310-20, per the Company’s accounting practices. Non-Agency RMBS - Overcollateralization Class: The Company has elected the fair value option for certain interests in Non-Agency RMBS which it refers to as the overcollateralization classes. The cash flows for these holdings are generally subordinate to all other interests of the trusts and generally only pay out funds when certain ratios are met and excess cash holdings, as determined by the trustee, are available for distribution to the overcollateralization class. Many of the investments in this group have no current cash flows and may not ever pay cash flows, depending on the loss experience of the collateral group supporting the investment. Estimating future cash flows for this group of Non-Agency RMBS investments is highly subjective and uncertain; therefore, the Company records these holdings at fair value with changes in fair value reflected in earnings. Changes in fair value of the overcollateralization classes are presented in Net unrealized gains (losses) on financial instruments at fair value on the Consolidated Statements of Operations.
Derivative Financial Instruments	Derivative Financial Instruments The Company’s investment policies permit it to enter into derivative contracts, including interest rate swaps, swaptions, mortgage options, futures, and interest rate caps to manage its interest rate risk and, from time to time, enhance investment returns. The Company’s derivatives are recorded as either assets or liabilities in the Consolidated Statements of Financial Condition and measured at fair value. These derivative financial instrument contracts are not designated as hedges for GAAP; therefore, all changes in fair value are recognized in earnings. The Company estimates the fair value of its derivative instruments as described in Note 5 of these consolidated financial statements. Net payments on derivative instruments are included in the Consolidated Statements of Cash Flows as a component of net income. Unrealized gains (losses) on derivatives are removed from net income to arrive at cash flows from operating activities. The Company elects to net the fair value of its derivative contracts by counterparty when appropriate. These contracts contain legally enforceable provisions that allow for netting or setting off of all individual derivative receivables and payables with each counterparty and therefore, the fair value of those derivative contracts are reported net by counterparty. The credit support annex provisions of the Company’s derivative contracts allow the parties to mitigate their credit risk by requiring the party which is in a net payable position to post collateral. As the Company elects to net by counterparty the fair value of derivative contracts, it also nets by counterparty any cash collateral exchanged as part of the derivative.
Sales, Securitizations, and Re-Securitizations	Sales, Securitizations, and Re-Securitizations The Company periodically enters into transactions in which it sells financial assets, such as MBS and mortgage loans. Gains and losses on sales of assets are calculated using the average cost method whereby the Company records a gain or loss on the difference between the average amortized cost of the asset and the proceeds from the sale. In addition, the Company from time to time securitizes or re-securitizes assets and sells tranches in the newly securitized assets. These transactions may be recorded as either sales, whereby the assets contributed to the securitization are removed from the Consolidated Statements of Financial Condition and a gain or loss is recognized, or as secured borrowings whereby the assets contributed to the securitization are not derecognized but rather the debt issued by the securitization entity are recorded to reflect the term financing of the assets. In these securitizations and re-securitizations, the Company may retain senior or subordinated interests in the securitized or re-securitized assets. In transfers that are considered secured borrowings, no gain or loss is recognized. Any difference in the proceeds received and the carrying value of the transferred asset is recorded as a premium or discount and amortized into earnings as an adjustment to yield.
Income Taxes	Income Taxes The Company has elected to be taxed as a REIT and intends to comply with the provision of the Code, with respect thereto. Accordingly, the Company will generally not be subject to federal, state or local income taxes to the extent that qualifying distributions are made to stockholders and as long as certain asset, income, distribution and stock ownership tests are met. If the Company failed to qualify as a REIT and did not qualify for certain statutory relief provisions, the Company would be subject to federal, state and local income taxes and may be precluded from qualifying as a REIT for the subsequent four taxable years following the year in which the REIT qualification was lost. The Company and CIM Funding TRS have made joint elections to treat CIM Funding TRS as a TRS. CIM Funding TRS is taxable as a domestic C corporation and subject to federal, state, and local income taxes based upon its taxable income. A tax position is recognized only when, based on management’s judgment regarding the application of income tax laws, it is more likely than not that the tax position will be sustained upon examination. The Company does not have any unrecognized tax positions that would affect its financial statements or require disclosure.
Net Income per Share	Net Income per Share The Company calculates basic net income per share by dividing net income for the period by the basic weighted-average shares of its common stock outstanding for that period. Diluted net income per share takes into account the effect of dilutive instruments such as unvested restricted stock.
Stock-Based Compensation	Stock-Based Compensation Compensation expense for equity based awards granted to the Company’s independent directors and stock based compensation awards granted to employees of the Company subject only to service condition is recognized on a straight-line basis over the vesting period of such awards, based upon the fair value of such awards at the grant date. The Company recognizes forfeitures when they occur and does not adjust the fair value of the grants for estimated forfeitures. For awards subject to vesting on a straight line basis, the total amount of expense is at least equal to the measured expense of each vested tranche. Awards subject to only a service condition are valued according to the market price for the Company’s common stock at the date of grant. For awards based on the performance of the Company’s stock price, the Company generally engages an independent appraisal company to determine the value of the shares at the date of grant, taking into account the underlying contingency risks associated with the performance criteria. The values of these grants are expensed ratably over their respective vesting periods (irrespective of achievement of the performance criteria) adjusted, as applicable, for forfeitures.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company’s estimates contemplate current conditions and how it expects them to change in the future, it is reasonably possible that actual conditions could be materially different than anticipated in those estimates, which could have a material adverse impact on the Company’s results of operations and its financial condition. Management has made significant estimates including in accounting for income recognition and OTTI on Agency and Non-Agency RMBS and IO MBS (Note 3), valuation of Agency MBS and Non-Agency RMBS (Notes 3 and 5), residential mortgage loans (Note 4), securitized debt (Note 7) and derivative instruments (Notes 5 and 9). Actual results could differ materially from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Derivatives and Hedging - Targeted improvements to Accounting for Hedging Activities (Topic 815) In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging - Targeted improvements to Accounting for Hedging Activities. This update is issued with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. In addition, the amendments in this update make certain targeted improvements to simplify the application of the hedge accounting guidance in current GAAP. The guidance in the ASU is effective for the Company as of January 1, 2019. Early adoption is allowed. The Company is not planning to early adopt and is currently evaluating what impact this update will have on the consolidated financial statements. Business Combinations - (Topic 805) In January 2017, the FASB issued ASU No. 2017-01, Business Combinations - Clarifying the Definition of a Business. This update clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. Under the current implementation guidance in Topic 805, there are three elements of a business-inputs, processes, and outputs. While an integrated set of assets and activities (collectively referred to as a “set”) that is a business usually has outputs, outputs are not required to be present. The amendments in this update provide a screen to determine when a set is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated. The guidance in the ASU is effective for the Company as of January 1, 2018. The adoption of this guidance will not have any impact on the Company's consolidated financial statements. Statement of Cash Flows - Restricted Cash - (Topic 230) In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows - Restricted Cash. This update requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update do not provide a definition of restricted cash or restricted cash equivalents. The guidance in the ASU is effective for the Company as of January 1, 2018. As of December 31, 2017, the Company has no restricted cash. The adoption of this guidance will not have any impact on the Company's consolidated financial statements. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments - (Topic 230) In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments. This update provides guidance on eight specific cash flow issues. The guidance is intended to reduce diversity in practice on those issues across all industries. The guidance in the ASU is effective for the Company as of January 1, 2018. Early adoption is allowed. The guidance is to be applied retrospectively, unless it is impracticable to do so for an issue, then the amendments related to that issue would be applied prospectively. The guidance in the ASU is effective for the Company as of January 1, 2018. The ASU will require the Company to include proceeds received from a securitization of the Company's assets as a noncash activity in the Consolidated Statement of Cash Flows. This requirement will be retrospectively applied to all Consolidated Statements of Cash Flows presented beginning the first quarter 2018. The adoption of this guidance will not have any impact on the net increase or decrease in cash and cash equivalents in the Company's Consolidated Statements of Cash Flows. Financial Instruments - Credit Losses - (Topic 326) In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments . This update replaces the current model for recognizing credit losses from an incurred credit loss model to a current expected credit loss (CECL) model for instruments measured at amortized cost and requires entities to record allowances for available-for-sale (AFS) debt securities when the fair value of an AFS debt security is below the amortized cost of the asset rather than reduce the carrying amount, as the Company does under the current OTTI model. This update also simplifies the accounting model for purchased credit-impaired debt securities and loans. The changes in the allowances created in accordance with this update will be recorded in earnings. The update also expands the disclosure requirements regarding the Company's assumptions, models, and methods for estimating the expected credit losses. In addition, the Company will disclose the amortized cost balance for each class of financial asset by credit quality indicator, disaggregated by the year of origination. The guidance in the ASU is effective for the Company as of January 1, 2020. Early adoption is allowed, beginning January 1, 2019. The standard requires entities to record a cumulative-effect adjustment to the statement of financial position as of the beginning of the first reporting period in which the guidance is effective. The Company is currently evaluating what impact this update will have on the consolidated financial statements. Share Based Payments - (Topic 718) In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting . Under this update companies will no longer record excess tax benefits and certain tax deficiencies associated with an award of equity instruments in additional paid-in capital. Instead, they will record all excess tax benefits and tax deficiencies as income tax expense or benefit in the income statement when the awards vest or are settled, and additional paid-in capital pools will be eliminated. The updated guidance will also allow the Company to repurchase more shares than it can today for tax withholding purposes without triggering liability accounting and to make a policy election to account for forfeitures as they occur. The guidance is to be applied using a modified retrospective transition method with a cumulative-effect adjustment recorded in retained earnings. The Company has adopted this guidance as of January 1, 2017. The adoption of this guidance did not have a significant impact on the Company's consolidated financial statements. Contingent Put and Call Options in Debt Instruments - (Topic 815) In March 2016, the FASB issued ASU No. 2016-06, Contingent Put and Call Options in Debt Instruments Accounting . This update clarifies that when a call or put option in a debt instrument can accelerate the repayment of principal on the debt instrument, a reporting entity does not need to assess whether the contingent event that triggers the ability to exercise the call or put option is related to interest rates or credit risk in determining whether the option should be accounted for separately as a derivative. The new guidance applies to existing debt instruments (or hybrid financial instruments that are determined to have a debt host) using a modified retrospective method as of the beginning of the period of adoption. The Company has adopted this guidance as of January 1, 2017. The adoption of this guidance did not have a significant impact on the Company’s consolidated financial statements. Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships - (Topic 815) In March 2016, the FASB issued ASU No. 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships. The amendments in this update clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not, in and of itself, require de-designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company has adopted this guidance as of January 1, 2017. The Company currently does not apply hedge accounting for GAAP reporting purposes, therefore this guidance did not have a significant impact on the Company’s consolidated financial statements. Financial Instruments-Overall (Subtopic 825-10) In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . This update changes how the Company will present changes in the fair value of financial liabilities measured under the fair value option that are attributable to our own credit. Under the updated guidance, the Company will record changes in instrument-specific credit risk for financial liabilities measured under the fair value option in other comprehensive income. The update also requires fair value measurement for equity investments that do not result in consolidation and are not accounted for under the equity method to be measured at fair value with any changes in fair value recognized in net income. The update also eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost. In addition, the Company will have to use the exit price notion when measuring the fair value of financial instruments measured at amortized cost for disclosure purposes. The guidance in the ASU is effective for the Company as of January 1, 2018. As the Company has no equity investments within the scope of this update, there will be no impact on the Company's consolidated financial statements. As of December 31, 2017, the Company has $9.4 billion of debt which is carried at fair value under the fair value option. This debt is issued by consolidated collateralized financing entities and are non-recourse to the Company, therefore, there is no instrument-specific credit risk related to these liabilities. This guidance will have no cumulative effect of adoption on the Company’s consolidated financial statements as of January 1, 2018.

Mortgage-Backed Securities (Tab

Mortgage-Backed Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The tables below present amortized cost, fair value and unrealized gain/losses of Company's MBS investments as of December 31, 2017 and December 31, 2016 . December 31, 2017 (dollars in thousands) Principal or Notional Value Total Premium Total Discount Amortized Cost Fair Value Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gain/(Loss) Non-Agency RMBS Senior $ 2,733,926 $ 540 $ (1,257,103 ) $ 1,477,363 $ 2,231,415 $ 754,234 $ (182 ) $ 754,052 Senior, interest-only 4,862,461 262,996 — 262,996 210,850 15,761 (67,907 ) (52,146 ) Subordinated 501,455 10,571 (177,206 ) 334,820 401,225 66,704 (299 ) 66,405 Subordinated, interest-only 201,378 7,369 — 7,369 7,826 902 (445 ) 457 Agency MBS Residential 2,227,128 123,245 — 2,350,373 2,322,180 5,706 (33,899 ) (28,193 ) Commercial 1,894,594 47,430 (4,685 ) 1,937,339 1,938,281 17,041 (16,099 ) 942 Interest-only 3,021,840 111,277 — 111,277 104,367 834 (7,744 ) (6,910 ) Total $ 15,442,782 $ 563,428 $ (1,438,994 ) $ 6,481,537 $ 7,216,144 $ 861,182 $ (126,575 ) $ 734,607 December 31, 2016 (dollars in thousands) Principal or Notional Value Total Premium Total Discount Amortized Cost Fair Value Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gain/(Loss) Non-Agency RMBS Senior $ 3,190,947 $ 231 $ (1,412,058 ) $ 1,779,120 $ 2,511,003 $ 732,133 $ (250 ) $ 731,883 Senior, interest-only 5,648,339 292,396 — 292,396 253,539 18,674 (57,531 ) (38,857 ) Subordinated 673,259 16,352 (212,734 ) 476,877 553,498 77,857 (1,236 ) 76,621 Subordinated, interest-only 266,927 13,878 — 13,878 12,024 — (1,854 ) (1,854 ) Agency MBS Residential 2,594,570 149,872 — 2,744,442 2,705,978 11,235 (49,699 ) (38,464 ) Commercial 1,331,543 37,782 (2,688 ) 1,366,637 1,316,975 175 (49,837 ) (49,662 ) Interest-only 3,356,491 152,175 — 152,175 144,800 1,893 (9,268 ) (7,375 ) Total $ 17,062,076 $ 662,686 $ (1,627,480 ) $ 6,825,525 $ 7,497,817 $ 841,967 $ (169,675 ) $ 672,292
Schedule of Changes in Accretable Yield	The table below presents changes in accretable yield, or the excess of the security’s cash flows expected to be collected over the Company’s investment, solely as it pertains to the Company’s Non-Agency RMBS portfolio accounted for according to the provisions of ASC 310-30. For the Year Ended December 31, 2017 December 31, 2016 (dollars in thousands) Balance at beginning of period $ 1,550,110 $ 1,742,744 Purchases 20,962 79,156 Yield income earned (266,214 ) (282,800 ) Reclassification (to) from non-accretable difference 18,909 53,681 Sales and deconsolidation (20,178 ) (42,671 ) Balance at end of period $ 1,303,589 $ 1,550,110
Schedule of Non-Agency RMBS Having Deteriorated Credit When Acquired	The table below presents the outstanding principal balance and related amortized cost at December 31, 2017 and December 31, 2016 as it pertains to the Company’s Non-Agency RMBS portfolio accounted for according to the provisions of ASC 310-30. For the Year Ended December 31, 2017 December 31, 2016 (dollars in thousands) Outstanding principal balance: Beginning of period $ 3,138,265 $ 3,550,698 End of period $ 2,673,350 $ 3,138,265 Amortized cost: Beginning of period $ 1,695,079 $ 1,958,726 End of period $ 1,381,839 $ 1,695,079
Schedule of Temporary Impairment Losses, Investments	The following tables present the gross unrealized losses and estimated fair value of the Company’s RMBS by length of time that such securities have been in a continuous unrealized loss position at December 31, 2017 and December 31, 2016 . All securities in an unrealized loss position have been evaluated by the Company for OTTI as discussed in Note 2(d). December 31, 2017 (dollars in thousands) Unrealized Loss Position for Less than 12 Months Unrealized Loss Position for 12 Months or More Total Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Non-Agency RMBS Senior $ 35,229 $ (182 ) 1 $ — $ — — $ 35,229 $ (182 ) 1 Senior, interest-only 28,129 (1,724 ) 27 120,120 (66,183 ) 120 148,249 (67,907 ) 147 Subordinated 235 (38 ) 7 6,261 (261 ) 5 6,496 (299 ) 12 Subordinated, interest-only — — — 945 (445 ) 3 945 (445 ) 3 Agency MBS Residential 660,103 (5,197 ) 21 1,471,464 (28,702 ) 93 2,131,567 (33,899 ) 114 Commercial 830,889 (11,695 ) 176 161,980 (4,404 ) 91 992,869 (16,099 ) 267 Interest-only 15,142 (641 ) 7 57,875 (7,103 ) 24 73,017 (7,744 ) 31 Total $ 1,569,727 $ (19,477 ) 239 $ 1,818,645 $ (107,098 ) 336 $ 3,388,372 $ (126,575 ) 575 December 31, 2016 (dollars in thousands) Unrealized Loss Position for Less than 12 Months Unrealized Loss Position for 12 Months or More Total Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Estimated Fair Value Unrealized Losses Number of Securities Non-Agency RMBS Senior $ 12,384 $ (250 ) 3 $ — $ — — $ 12,384 $ (250 ) 3 Senior, interest-only 96,399 (13,600 ) 62 78,516 (43,931 ) 86 174,915 (57,531 ) 148 Subordinated 56,015 (412 ) 7 2,826 (824 ) 4 58,841 (1,236 ) 11 Subordinated, interest-only 748 (230 ) 2 11,276 (1,624 ) 3 12,024 (1,854 ) 5 Agency MBS Residential 2,338,910 (48,084 ) 106 54,943 (1,615 ) 1 2,393,853 (49,699 ) 107 Commercial 1,247,923 (45,802 ) 646 51,733 (4,035 ) 46 1,299,656 (49,837 ) 692 Interest-only 63,506 (2,170 ) 20 52,963 (7,098 ) 16 116,469 (9,268 ) 36 Total $ 3,815,885 $ (110,548 ) 846 $ 252,257 $ (59,127 ) 156 $ 4,068,142 $ (169,675 ) 1,002
Other than Temporary Impairment, Credit Losses Recognized in Earnings	A summary of the OTTI included in earnings for the years ended December 31, 2017 , 2016 and 2015 are presented below. For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Total other-than-temporary impairment losses $ (5,169 ) $ (9,589 ) $ (8,700 ) Portion of loss recognized in other comprehensive income (loss) (56,687 ) (48,398 ) (58,744 ) Net other-than-temporary credit impairment losses $ (61,856 ) $ (57,987 ) $ (67,444 ) The following table presents a roll forward of the credit loss component of OTTI on the Company’s Non-Agency RMBS for which a portion of loss was previously recognized in OCI. The table delineates between those securities that are recognizing OTTI for the first time as opposed to those that have previously recognized OTTI. For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Cumulative credit loss beginning balance $ 556,485 $ 529,112 $ 507,548 Additions: Other-than-temporary impairments not previously recognized 12,669 25,959 41,233 Reductions for securities sold or deconsolidated during the period (12,405 ) (9,429 ) (19,746 ) Increases related to other-than-temporary impairments on securities with previously recognized other-than-temporary impairments 47,211 32,027 26,138 Reductions for increases in cash flows expected to be collected over the remaining life of the securities (12,439 ) (21,184 ) (26,061 ) Cumulative credit impairment loss ending balance $ 591,521 $ 556,485 $ 529,112
Other than Temporary Impairment of Investments Recorded in Earnings, Significant Inputs and Assumptions	The significant inputs used to measure the component of OTTI recognized in earnings for the Company’s Non-Agency RMBS for the periods reported are summarized as follows: For the Year Ended December 31, 2017 December 31, 2016 Loss Severity Weighted Average 64% 58% Range 28% - 89% 25% - 85% 60+ days delinquent Weighted Average 21% 21% Range 11% - 27% 0% - 40% Credit Enhancement (1) Weighted Average 16% 25% Range 0% - 50% 0% - 100% 3 Month CPR Weighted Average 10% 7% Range 0% - 24% 0% - 27% 12 Month CPR Weighted Average 11% 6% Range 1% - 19% 1% - 24% (1) Calculated as the combined credit enhancement to the Re-REMIC and underlying from each of their respective capital structures.
Summary of Unrealized Gains and Losses on MBS	The following tables present a summary of unrealized gains and losses at December 31, 2017 and December 31, 2016 . IO MBS included in the tables below represent the right to receive a specified portion of the contractual interest cash flows of the underlying principal balance of specific securities. At December 31, 2017 , IO MBS had a fair value of $323 million , an amortized cost of $382 million and net unrealized losses of $59 million . At December 31, 2016 , IO MBS had a fair value of $410 million , an amortized cost of $458 million and net unrealized losses of $48 million . All changes in fair value of IOs are reflected in Net Income in the Consolidated Statements of Operations. December 31, 2017 (dollars in thousands) Gross Unrealized Gain Included in Accumulated Other Comprehensive Income Gross Unrealized Gain Included in Cumulative Earnings Total Gross Unrealized Gain Gross Unrealized Loss Included in Accumulated Other Comprehensive Income Gross Unrealized Loss Included in Cumulative Earnings Total Gross Unrealized Loss Non-Agency RMBS Senior $ 754,234 $ — $ 754,234 $ (182 ) $ — $ (182 ) Senior, interest-only — 15,761 15,761 — (67,907 ) (67,907 ) Subordinated 62,989 3,715 66,704 (102 ) (197 ) (299 ) Subordinated, interest-only — 902 902 — (445 ) (445 ) Agency MBS Residential 5,706 — 5,706 (29,083 ) (4,816 ) (33,899 ) Commercial 15,462 1,579 17,041 (12,122 ) (3,977 ) (16,099 ) Interest-only — 834 834 — (7,744 ) (7,744 ) Total $ 838,391 $ 22,791 $ 861,182 $ (41,489 ) $ (85,086 ) $ (126,575 ) December 31, 2016 (dollars in thousands) Gross Unrealized Gain Included in Accumulated Other Comprehensive Income Gross Unrealized Gain Included in Cumulative Earnings Total Gross Unrealized Gain Gross Unrealized Loss Included in Accumulated Other Comprehensive Income Gross Unrealized Loss Included in Cumulative Earnings Total Gross Unrealized Loss Non-Agency RMBS Senior $ 732,133 $ — $ 732,133 $ (250 ) $ — $ (250 ) Senior, interest-only — 18,674 18,674 — (57,531 ) (57,531 ) Subordinated 74,584 3,273 77,857 (235 ) (1,001 ) (1,236 ) Subordinated, interest-only — — — — (1,854 ) (1,854 ) Agency MBS Residential 11,235 — 11,235 (49,699 ) — (49,699 ) Commercial 175 — 175 (49,837 ) — (49,837 ) Interest-only — 1,893 1,893 — (9,268 ) (9,268 ) Total $ 818,127 $ 23,840 $ 841,967 $ (100,021 ) $ (69,654 ) $ (169,675 )
Residential Mortgage Backed Securities Collateral Characteristics	The following tables provide a summary of the Company’s MBS portfolio at December 31, 2017 and December 31, 2016 . December 31, 2017 Principal or Notional Value Weighted Average Amortized Weighted Average Fair Value Weighted Average Weighted Average Yield at Period-End (1) Non-Agency RMBS Senior $ 2,733,926 $ 54.04 $ 81.62 4.6 % 16.7 % Senior, interest-only 4,862,461 5.41 4.34 1.3 % 8.0 % Subordinated 501,455 66.77 80.01 4.1 % 9.6 % Subordinated, interest-only 201,378 3.66 3.89 0.8 % 11.8 % Agency MBS Residential pass-through 2,227,128 105.53 104.27 3.8 % 2.9 % Commercial pass-through 1,894,594 102.26 102.31 3.6 % 3.2 % Interest-only 3,021,840 3.68 3.45 0.7 % 3.4 % (1) Bond Equivalent Yield at period end. December 31, 2016 Principal or Notional Value at Period-End Weighted Average Amortized Weighted Average Fair Value Weighted Average Weighted Average Yield at Period-End (1) Non-Agency RMBS Senior $ 3,190,947 $ 55.76 $ 78.69 4.3 % 15.5 % Senior, interest-only 5,648,339 5.18 4.49 1.5 % 11.7 % Subordinated 673,259 70.83 82.21 3.8 % 9.2 % Subordinated, interest-only 266,927 5.20 4.50 1.1 % 13.5 % Agency MBS Residential pass-through 2,594,570 105.78 104.29 3.9 % 3.0 % Commercial pass-through 1,331,543 102.64 98.91 3.6 % 2.9 % Interest-only 3,356,491 4.53 4.31 0.8 % 3.5 % (1) Bond Equivalent Yield at period end.
Credit Ratings of Residential Mortgage-Backed Securities	The following table presents the weighted average credit rating of the Company’s Non-Agency RMBS portfolio at December 31, 2017 and December 31, 2016 . December 31, 2017 December 31, 2016 AAA 0.3 % 0.3 % AA 0.3 % 0.3 % A 0.6 % 0.7 % BBB 1.9 % 0.7 % BB 2.5 % 3.0 % B 2.3 % 3.9 % Below B 59.6 % 67.2 % Not Rated 32.5 % 23.9 % Total 100.0 % 100.0 %
Schedule of Mortgage-Backed Securities by Estimated Weighted Average Life Classification	The following tables provide a summary of the fair value and amortized cost of the Company’s MBS at December 31, 2017 and December 31, 2016 according to their estimated weighted-average life classifications. The weighted-average lives of the MBS in the tables below are based on lifetime expected prepayment rates using an industry prepayment model for the Agency MBS portfolio and the Company’s prepayment assumptions for the Non-Agency RMBS. The prepayment model considers current yield, forward yield, steepness of the interest rate curve, current mortgage rates, mortgage rates of the outstanding loan, loan age, margin, and volatility. December 31, 2017 (dollars in thousands) Weighted Average Life Less than one year Greater than one year and less than five years Greater than five years and less than ten years Greater than ten years Total Fair value Non-Agency RMBS Senior $ 2,179 $ 681,086 $ 910,234 $ 637,916 $ 2,231,415 Senior interest-only 19 54,107 72,702 84,022 210,850 Subordinated — 75,495 121,555 204,175 401,225 Subordinated interest-only — 7,165 661 — 7,826 Agency MBS Residential — 21,777 2,300,403 — 2,322,180 Commercial — 45,770 16,559 1,875,952 1,938,281 Interest-only — 74,490 25,271 4,606 104,367 Total fair value $ 2,198 $ 959,890 $ 3,447,385 $ 2,806,671 $ 7,216,144 Amortized cost Non-Agency RMBS Senior $ 2,124 $ 493,965 $ 569,458 $ 411,816 $ 1,477,363 Senior interest-only 1,271 73,758 94,145 93,822 262,996 Subordinated — 61,987 91,044 181,789 334,820 Subordinated interest-only — 6,355 1,014 — 7,369 Agency MBS Residential — 22,069 2,328,304 — 2,350,373 Commercial — 47,170 17,176 1,872,993 1,937,339 Interest-only — 79,356 27,582 4,339 111,277 Total amortized cost $ 3,395 $ 784,660 $ 3,128,723 $ 2,564,759 $ 6,481,537 December 31, 2016 (dollars in thousands) Weighted Average Life Less than one year Greater than one year and less than five years Greater than five years and less than ten years Greater than ten years Total Fair value Non-Agency RMBS Senior $ 25,612 $ 508,979 $ 1,267,000 $ 709,412 $ 2,511,003 Senior interest-only 417 37,796 115,780 99,546 253,539 Subordinated — 94,793 238,630 220,075 553,498 Subordinated interest-only — — 12,024 — 12,024 Agency MBS Residential — 429,869 2,276,109 — 2,705,978 Commercial — 47,354 16,833 1,252,788 1,316,975 Interest-only — 75,863 63,715 5,222 144,800 Total fair value $ 26,029 $ 1,194,654 $ 3,990,091 $ 2,287,043 $ 7,497,817 Amortized cost Non-Agency RMBS Senior $ 21,423 $ 403,250 $ 868,624 $ 485,823 $ 1,779,120 Senior interest-only 1,992 50,252 134,642 105,510 292,396 Subordinated — 76,287 195,538 205,052 476,877 Subordinated interest-only — — 13,878 — 13,878 Agency MBS Residential — 438,270 2,306,172 — 2,744,442 Commercial — 49,027 17,247 1,300,363 1,366,637 Interest-only — 77,598 69,333 5,244 152,175 Total amortized cost $ 23,415 $ 1,094,684 $ 3,605,434 $ 2,101,992 $ 6,825,525
Schedule of Collateral Characteristics of Underlying Mortgages of Non-Agency RMBS Portfolio	The Non-Agency RMBS in the Portfolio have the following collateral characteristics at December 31, 2017 and December 31, 2016 . December 31, 2017 December 31, 2016 Weighted average maturity (years) 20.7 21.6 Weighted average amortized loan to value (1) 64.4 % 66.5 % Weighted average FICO (2) 697 698 Weighted average loan balance (in thousands) $ 314 $ 319 Weighted average percentage owner occupied 84.4 % 83.2 % Weighted average percentage single family residence 66.3 % 65.8 % Weighted average current credit enhancement 2.2 % 2.3 % Weighted average geographic concentration of top four states CA 31.7 % CA 32.1 % NY 8.5 % FL 8.1 % FL 8.3 % NY 7.9 % NJ 2.7 % NJ 2.7 % (1) Value represents appraised value of the collateral at the time of loan origination. (2) FICO as determined at the time of loan origination.
Schedule of Percentage of Non-Agency RMBS by Year Originated	The table below presents the origination year of the underlying loans related to the Company’s portfolio of Non-Agency RMBS at December 31, 2017 and December 31, 2016 . Origination Year December 31, 2017 December 31, 2016 2003 and prior 3.6 % 3.6 % 2004 4.3 % 4.2 % 2005 20.8 % 20.2 % 2006 38.2 % 38.0 % 2007 30.4 % 31.3 % 2008 1.8 % 1.8 % 2009 and later 0.9 % 0.9 % Total 100.0 % 100.0 %
Schedule of Gains and Losses from Sales of Investments	The proceeds and gross realized gains and gross realized losses from sales of investments for the years ended December 31, 2017 , 2016 and 2015 are as follows: For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Proceeds from sales $ 812,005 $ 2,719,329 $ 6,244,613 Gross realized gains 17,538 28,572 94,618 Gross realized losses (8,415 ) (10,417 ) (17,544 ) Net realized gain (loss) $ 9,123 $ 18,155 $ 77,074

Loans Held for Investment (Tabl

Loans Held for Investment (Tables)	12 Months Ended
	Dec. 31, 2017
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Summary of Changes in Carrying Value of Securitized Loans Held for Investment Carried at Fair Value	The following table provides a summary of the changes in the carrying value of Loans held for investment at fair value at December 31, 2017 and December 31, 2016 : For the Year Ended December 31, 2017 December 31, 2016 (dollars in thousands) Balance, beginning of period $ 8,753,653 $ 4,768,416 Purchases 6,539,765 4,897,370 Principal paydowns (1,788,409 ) (1,022,414 ) Sales and settlements 2,876 5,007 Net periodic accretion (amortization) (35,803 ) (41,363 ) Change in fair value 206,181 146,637 Balance, end of period $ 13,678,263 $ 8,753,653
Schedule of Percentage of Securitized Loans Held for Investment Carried at Fair Value by Year Originated	The loan portfolio for all residential mortgages were originated during the following years: Origination Year December 31, 2017 December 31, 2016 2002 and prior 7.5 % 8.9 % 2003 6.7 % 5.2 % 2004 14.6 % 11.9 % 2005 20.4 % 20.5 % 2006 23.1 % 22.0 % 2007 19.0 % 20.9 % 2008 6.0 % 6.5 % 2009 0.7 % 0.6 % 2010 and later 2.0 % 3.5 % Total 100.0 % 100.0 %
Schedule Of Securitized Loans Held For Investment Types And Characteristics Of Underlying Collateral	The following tables show various characteristics of our residential loan portfolio and outstanding principal balance of the loans that are 30 days delinquent and greater for the years ended December 31, 2017 and 2016, respectively. December 31, 2017 (dollars in thousands) Loan Balance Number of Loans Interest Rate Maturity Date Total Principal 30-89 Days Delinquent 90+ Days Delinquent Held-for-Investment at fair value: Adjustable rate loans: $1 to $250 9,227 1.00% to 18.74% 9/1/1992 - 6/1/2057 $ 827,020 $ 95,952 $ 46,343 $250 to $500 529 2.00% to 11.88% 11/1/2028 - 12/1/2056 171,266 19,289 11,855 $500 to $750 67 2.00% to 9.25% 1/1/2034 - 9/1/2046 39,212 3,041 2,382 $750 to $1,000 9 3.88% to 5.55% 1/1/2035 - 12/1/2045 7,663 757 — Over $1,000 8 3.88% to 4.00% 7/1/2037 - 8/1/2039 13,702 2,705 1,164 9,840 $ 1,058,863 $ 121,744 $ 61,744 Hybrid loans: $500 to $750 1 6.88% to 6.88% 1/1/2038 - 1/1/2038 $ 702 $ — $ — 1 $ 702 $ — $ — Fixed loans: $1 to $250 133,437 0.00% to 24.00% 9/1/1994 - 5/1/2062 $ 10,371,829 $ 960,564 $ 562,271 $250 to $500 5,324 0.00% to 12.52% 4/1/2018 - 11/1/2065 1,713,839 188,257 114,616 $500 to $750 440 2.00% to 10.69% 7/1/2031 - 9/1/2057 258,058 12,789 13,459 $750 to $1,000 99 2.00% to 7.69% 3/1/2013 - 12/1/2055 84,701 1,706 877 Over $1,000 31 3.00% to 5.75% 12/1/2040 - 7/1/2056 37,828 1,155 — 139,331 $ 12,466,255 $ 1,164,471 $ 691,223 Total 149,172 $ 13,525,820 $ 1,286,215 $ 752,967 The foreclosure, bankruptcy and REO balances on our loans were $200 million , $273 million and $31 million , respectively, as of December 31, 2017, which are included in the table above. December 31, 2016 (dollars in thousands) Loan Balance Number of Loans Interest Rate Maturity Date Total Principal 30-89 Days Delinquent 90+ Days Delinquent Held-for-Investment at fair value: Adjustable rate loans: $1 to $250 6,417 1.38% to 15.20% 2/1/2003 - 10/1/2056 $ 609,584 $ 67,705 $ 25,102 $250 to $500 458 2.13% to 10.00% 4/1/2030 - 9/1/2055 147,410 22,821 7,684 $500 to $750 45 2.00% to 9.25% 7/1/2034 - 9/1/2046 26,383 $ 3,033 1,131 $750 to $1,000 7 3.13% to 5.17% 1/1/2038 - 12/1/2045 5,754 $ 768 — Over $1,000 5 3.13% to 3.38% 1/1/2038 - 4/1/2038 6,641 $ — 1,428 6,932 795,772 94,326 35,345 Hybrid loans: $1 to $250 2 6.67% to 6.83% 8/1/2037 - 9/1/2037 $ 190 $ 97 $ — $250 to $500 1 5.88% to 5.88% 7/1/2037 - 7/1/2037 496 — — $500 to $750 3 5.63% to 6.88% 7/1/2037 - 3/1/2038 1,842 — — $750 to $1,000 1 5.75% to 5.75% 4/1/2037 - 4/1/2037 940 — — 7 $ 3,468 $ 97 $ — Fixed loans: $1 to $250 83,925 0.00% to 24.00% 7/1/2002 - 5/1/2062 $ 6,487,251 $ 603,388 $ 424,980 $250 to $500 3,769 0.00% to 12.52% 5/1/2018 - 10/1/2065 1,225,999 136,702 80,984 $500 to $750 381 2.00% to 10.69% 5/1/2032 - 9/1/2057 223,638 9,531 5,788 $750 to $1,000 103 3.75% to 7.29% 4/1/2037 - 5/1/2047 87,680 — 1,746 Over $1,000 38 3.25% to 7.13% 3/1/2013 - 8/1/2046 44,975 — — 88,216 $ 8,069,543 $ 749,621 $ 513,498 Total 95,155 $ 8,868,783 $ 844,044 $ 548,843
Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Schedule of Securitized Loans Held for Investment Carried at Fair Value Key Characteristics of Underlying Collateral	The following table presents a summary of key characteristics of the residential loan portfolio at December 31, 2017 and December 31, 2016 : December 31, 2017 December 31, 2016 Number of loans 149,172 95,155 Weighted average maturity (years) 18.8 19.8 Weighted average loan to value (1) 88.0 % 86.9 % Weighted average FICO (1) 631 627 Weighted average loan balance (in thousands) $ 91 $ 93 Weighted average percentage owner occupied 95.0 % 96.6 % Weighted average percentage single family residence 86.0 % 85.0 % Weighted average geographic concentration of top five states CA 9.0 % CA 10.0 % FL 7.2 % FL 6.7 % OH 6.1 % OH 6.5 % PA 5.6 % VA 5.9 % VA 5.5 % NC 5.1 % (1) As provided by the Trustee.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Option, Quantitative Disclosures	The table below shows the unpaid principal, fair value and impact of change in fair value on each of the financial instruments carried with fair value option as of December 31, 2017 and 2016 , respectively: December 31, 2017 (dollars in thousands) Unpaid Fair Value Quarter to Date Gain/(Loss) on Change in Fair Value Year to Date Gain/(Loss) on Change in Fair Value Assets: Non-agency RMBS Subordinated N/A $ 13,993 $ (545 ) $ 1,246 Senior, interest-only 4,862,461 210,850 3,156 (13,290 ) Subordinated, interest-only 201,378 7,826 1,836 2,311 Agency MBS Residential Pass-through 577,522 602,829 (2,359 ) (4,816 ) Commercial Pass-through 564,379 570,105 (546 ) (2,398 ) Interest-only 3,021,840 104,367 (367 ) 465 Loans held for investment, at fair value 13,525,820 13,678,263 (65,643 ) 206,181 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 9,395,854 9,388,657 16,831 (78,289 ) December 31, 2016 (dollars in thousands) Unpaid Fair Value Quarter to Date Gain/(Loss) on Change in Fair Value Year to Date Gain/(Loss) on Change in Fair Value Assets: Non-agency RMBS Subordinated N/A $ 18,602 $ (1,983 ) $ 5,568 Senior, interest-only 5,648,339 253,539 (26,844 ) (4,512 ) Subordinated, interest-only 266,927 12,024 (1,169 ) 2,118 Agency MBS Interest-only 3,356,491 144,800 (920 ) (490 ) Loans held for investment, at fair value 8,868,783 8,753,653 32,991 146,635 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 7,059,265 6,941,097 (22,738 ) (89,767 )
Fair Value, Financial Assets and Liabilities Carried at Fair Value on a Recurring Basis	The Company’s financial assets and liabilities carried at fair value on a recurring basis, including the level in the fair value hierarchy, at December 31, 2017 and December 31, 2016 are presented below. December 31, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Counterparty and Cash Collateral, netting Total Assets: Non-Agency RMBS, at fair value $ — $ — $ 2,851,316 $ — $ 2,851,316 Agency MBS, at fair value — 4,364,828 — — 4,364,828 Loans held for investment, at fair value — — 13,678,263 — 13,678,263 Derivatives 3,553 46,978 — (1,617 ) 48,914 Liabilities: Securitized debt at fair value, collateralized by loans held for investment — — (9,388,657 ) — (9,388,657 ) Derivatives — (1,937 ) — 1,617 (320 ) December 31, 2016 (dollars in thousands) Level 1 Level 2 Level 3 Counterparty and Cash Collateral, netting Total Assets: Non-Agency RMBS, at fair value $ — $ — 3,330,063 $ — $ 3,330,063 Agency MBS, at fair value — 4,167,754 — — 4,167,754 Loans held for investment, at fair value — — 8,753,653 — 8,753,653 Derivatives 1,785 22,327 — (14,435 ) 9,677 Liabilities: Securitized debt at fair value, collateralized by loans held for investment — — (6,941,097 ) — (6,941,097 ) Derivatives — (17,225 ) — 14,875 (2,350 )
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The table below provides a summary of the changes in the fair value of securities classified as Level 3 at December 31, 2017 and December 31, 2016 . Fair Value Reconciliation, Level 3 For the Year Ended, December 31, 2017 (dollars in thousands) Non-Agency RMBS Loans held for investment Securitized Debt Beginning balance Level 3 assets $ 3,330,063 $ 8,753,653 $ (6,941,097 ) Transfers in to Level 3 assets 6,112 — — Transfers out of Level 3 assets — — — Purchases 78,400 6,539,765 (5,173,430 ) Principal payments (568,339 ) (1,788,409 ) 1,787,368 Sales and Settlements (68,162 ) 2,876 1,056,765 Accretion (amortization) of purchase discounts 120,119 (35,803 ) (4,701 ) Gains (losses) included in net income Other than temporary credit impairment losses (59,881 ) — — Realized gains (losses) on sales and settlements 12,031 — (35,273 ) Net unrealized gains (losses) included in income (9,733 ) 206,181 (78,289 ) Gains (losses) included in other comprehensive income Total unrealized gains (losses) for the period 10,706 — — Ending balance Level 3 assets $ 2,851,316 $ 13,678,263 $ (9,388,657 ) Fair Value Reconciliation, Level 3 For the Year Ended, December 31, 2016 (dollars in thousands) Non-Agency RMBS Loans held for investment Securitized Debt Beginning balance Level 3 assets $ 3,675,841 $ 4,768,416 $ (3,720,496 ) Transfers in to Level 3 assets — — — Transfers out of Level 3 assets — — — Purchases 257,914 4,897,370 (4,797,255 ) Principal payments (532,696 ) (1,022,414 ) 1,059,854 Sales and Settlements (149,938 ) 5,007 608,816 Accretion (amortization) of purchase discounts 120,638 (41,363 ) (2,128 ) Gains (losses) included in net income Other than temporary credit impairment losses (57,986 ) — — Realized gains (losses) on sales and settlements 13,761 — (122 ) Net unrealized gains (losses) included in income 3,173 146,637 (89,766 ) Gains (losses) included in other comprehensive income Total unrealized gains (losses) for the period (644 ) — — Ending balance Level 3 assets $ 3,330,063 $ 8,753,653 $ (6,941,097 )
Fair Value Measurements, Significant Unobservable Inputs, Liabilities	A summary of the significant inputs used to estimate the fair value of securitized debt at fair value, collateralized by loans held for investment, as of December 31, 2017 and December 31, 2016 follows: December 31, 2017 December 31, 2016 Significant Inputs Significant Inputs Weighted Average Discount Rate CPR Range CDR Range Loss Severity Range Weighted Average Discount Rate CPR Range CDR Range Loss Severity Range Securitized debt at fair value, collateralized by loans held for investment 4.1% 6% - 15% 0% - 6% 35% - 60% 4.4% 1% - 35% 0% - 30% 35% - 65%
Fair Value, by Balance Sheet Grouping	The following table presents the carrying value and fair value, as described above, of the Company’s financial instruments not carried at fair value on a recurring basis at December 31, 2017 and December 31, 2016 . December 31, 2017 (dollars in thousands) Level in Fair Value Hierarchy Carrying Amount Fair Value Repurchase agreements 2 7,250,452 7,269,193 Securitized debt, collateralized by Non-Agency RMBS 3 205,780 192,259 December 31, 2016 (dollars in thousands) Level in Fair Value Hierarchy Carrying Amount Fair Value Repurchase agreements 2 5,600,903 5,619,385 Securitized debt, collateralized by Non-Agency RMBS 3 334,124 324,261
Non-agency MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Significant Unobservable Inputs, Assets	A summary of the significant inputs used to estimate the fair value of Non-Agency RMBS held for investment at fair value as of December 31, 2017 and December 31, 2016 follows: December 31, 2017 December 31, 2016 Significant Inputs Significant Inputs Weighted Average Discount Rate CPR CDR Loss Severity Weighted Average Discount Rate CPR CDR Loss Severity Range Range Non-Agency RMBS Senior 4.4% 1% -45% 0% -55% 35% -89% 5.4% 1% -35% 0% -22% 35% -95% Senior interest-only 11.2% 3% -25% 0% -50% 35% -95% 12.5% 3% -30% 0% -22% 35% -95% Subordinated 5.8% 1% -20% 0% -33% 35% -69% 6.2% 1% -25% 0% -18% 0% -79% Subordinated interest-only 12.0% 6% -22% 0% -9% 35% -63% 13.2% 6% -15% 0% -11% 35% -76%
Loans Held for Investment at Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Significant Unobservable Inputs, Assets	A summary of the significant inputs used to estimate the fair value of Loans held for investment collateralized by seasoned subprime mortgages at fair value as of December 31, 2017 and December 31, 2016 follows: December 31, 2017 December 31, 2016 Factor: Coupon Base Rate 4.8% 5.2% Actual 6.9% 7.1% FICO Base Rate 636 632 Actual 627 621 Loan-to-value (LTV) Base Rate 89% 87% Actual 88% 88% Loan Characteristics: Occupancy Owner Occupied 95% 97% Investor 1% 2% Secondary 4% 1% Property Type Single family 87% 86% Manufactured housing 4% 6% Multi-family/mixed use/other 9% 8%

Repurchase Agreements (Tables)

Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Repurchase Agreements	The repurchase agreements outstanding, weighted average borrowing rates, weighted average remaining maturities, average daily balances and the fair value of collateral pledged as of December 31, 2017 and December 31, 2016 were: December 31, 2017 December 31, 2016 Repurchase agreements outstanding secured by: Agency MBS (in thousands) $ 3,202,056 $ 3,087,734 Non-agency MBS and Loans held for investment (in thousands) 4,048,396 2,513,169 Total: $ 7,250,452 $ 5,600,903 Average balance of Repurchase agreements secured by: Agency MBS (in thousands) $ 3,120,474 $ 4,159,651 Non-agency MBS and Loans held for investment (in thousands) 3,203,700 2,322,683 Total: $ 6,324,174 $ 6,482,334 Average borrowing rate of Repurchase agreements secured by: Agency MBS 1.47 % 0.90 % Non-agency MBS and Loans held for investment 3.41 % 3.05 % Average remaining maturity of Repurchase agreements secured by: Agency MBS 28 Days 32 Days Non-agency MBS and Loans held for investment 93 Days 98 Days Average original maturity of Repurchase agreements secured by: Agency MBS 87 Days 112 Days Non-agency MBS and Loans held for investment 123 Days 155 Days MBS pledged as collateral at fair value on Repurchase agreements: Agency MBS (in thousands) $ 3,450,123 $ 3,334,245 Non-agency MBS and Loans held for investment (in thousands) 5,338,557 3,699,621 Total: $ 8,788,680 $ 7,033,866 At December 31, 2017 and December 31, 2016 , the repurchase agreements collateralized by MBS and Loans held for investment had the following remaining maturities. December 31, 2017 December 31, 2016 (dollars in thousands) Overnight $ — $ — 1 to 29 days 4,745,342 2,947,604 30 to 59 days 1,206,769 958,956 60 to 89 days 592,865 407,625 90 to 119 days — 559,533 Greater than or equal to 120 days 705,476 727,185 Total $ 7,250,452 $ 5,600,903

Securitized Debt (Tables)

Securitized Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Instrument [Line Items]
Schedule of Callable Debt	The following table presents the par value of the callable debt by year at December 31, 2017 . December 31, 2017 (dollars in thousands) Year Principal 2018 $ 943,573 2019 397,734 2020 4,744,768 2021 2,811,850 2022 287,157 Total $ 9,185,082
Non-agency MBS
Debt Instrument [Line Items]
Schedule of Maturities of Long-term Debt	The following table presents the estimated principal repayment schedule of the securitized debt collateralized by Non-Agency RMBS at December 31, 2017 and December 31, 2016 , based on expected cash flows of the residential mortgage loans or RMBS, as adjusted for projected losses on the underlying collateral of the debt. All of the securitized debt recorded in the Company’s Consolidated Statements of Financial Condition is non-recourse to the Company. December 31, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 42,217 $ 98,565 One to Three Years 45,916 82,563 Three to Five Years 16,524 23,854 Greater Than Five Years 4,867 31,973 Total $ 109,524 $ 236,955
Loans held for investment
Debt Instrument [Line Items]
Schedule of Maturities of Long-term Debt	The following table presents the estimated principal repayment schedule of the securitized debt collateralized by loans held for investment at December 31, 2017 and December 31, 2016 , based on expected cash flows of the residential mortgage loans or RMBS, as adjusted for projected losses on the underlying collateral of the debt. All of the securitized debt recorded in the Company’s Consolidated Statements of Financial Condition is non-recourse to the Company. December 31, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 1,819,018 $ 1,151,519 One to Three Years 2,872,572 1,841,808 Three to Five Years 2,140,434 1,423,706 Greater Than Five Years 2,439,872 2,477,123 Total $ 9,271,896 $ 6,894,156

Consolidated Securitization V32

Consolidated Securitization Vehicles and Other Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Consolidated Securitization Entities on Financial Condition	The consolidation of these Trusts resulted in the addition of the following amounts, net of eliminations, at the time of securitization. Consolidated Trusts (dollars in thousands) Assets: Loans held for investment, at fair value $ 7,407,677 Other Assets 51,711 Liabilities: Securitized debt at fair value (1) $ 5,188,457 (1) After the elimination of intercompany balances. The table below reflects the assets and liabilities recorded in the Consolidated Statements of Financial Condition related to the consolidated VIEs as of December 31, 2017 and December 31, 2016 . December 31, 2017 December 31, 2016 (dollars in thousands) Assets: Non-Agency RMBS, at fair value $ 1,579,793 $ 1,842,080 Loans held for investment, at fair value 13,263,338 8,753,653 Accrued interest receivable 75,489 57,153 Other assets 68,844 109,068 Liabilities: Securitized debt, collateralized by Non-Agency RMBS $ 205,780 $ 334,124 Securitized debt at fair value, collateralized by loans held for investment 9,388,657 6,941,097 Accrued interest payable 33,870 24,942 Other liabilities 3,513 2,742
Schedule of Consolidated Variable Interest Entities Effects on Operating Results	Income, OTTI and expense amounts related to consolidated VIEs recorded in the Consolidated Statements of Operations is presented in the tables below. For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Interest income, Assets of consolidated VIEs $ 914,022 $ 678,623 $ 575,715 Interest expense, Non-recourse liabilities of VIEs 390,858 249,708 191,922 Net interest income $ 523,164 $ 428,915 $ 383,793 Total other-than-temporary impairment losses $ (2,174 ) $ (1,274 ) $ (2,066 ) Portion of loss recognized in other comprehensive income (loss) (51,118 ) (37,475 ) (55,552 ) Net other-than-temporary credit impairment losses $ (53,292 ) $ (38,749 ) $ (57,618 ) Servicing fees $ 41,493 $ 31,178 $ 25,244

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position	The table below summarizes the location and fair value of the derivatives reported in the Consolidated Statements of Financial Condition after counterparty netting and posting of cash collateral as of December 31, 2017 and December 31, 2016 . December 31, 2017 Derivative Assets Derivative Liabilities Derivative Instruments Notional Amount Outstanding Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value (dollars in thousands) Interest Rate Swaps $ 3,816,400 Derivatives, at fair value, net $ 43,257 Derivatives, at fair value, net $ — Swaptions 391,000 Derivatives, at fair value, net 2,105 Derivatives, at fair value, net (320 ) Treasury Futures 619,700 Derivatives, at fair value, net 3,552 Derivatives, at fair value, net — Total $ 4,827,100 $ 48,914 $ (320 ) December 31, 2016 Derivative Assets Derivative Liabilities Derivative Instruments Notional Amount Outstanding Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value Location on Consolidated Statements of Financial Condition Net Estimated Fair Value/Carrying Value (dollars in thousands) Interest Rate Swaps $ 1,396,900 Derivatives, at fair value, net $ — Derivatives, at fair value, net $ — Swaptions 624,000 Derivatives, at fair value, net 7,892 Derivatives, at fair value, net (2,350 ) Treasury Futures 619,700 Derivatives, at fair value, net 1,785 Derivatives, at fair value, net — Total $ 2,640,600 $ 9,677 $ (2,350 )
Schedule of Derivative Instruments Effects on Operating Results	The effect of the Company’s derivatives on the Consolidated Statements of Operations is presented below. Net gains (losses) on derivatives Derivative Instruments Location on Consolidated Statements of December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Interest Rate Swaps Net unrealized gains (losses) on derivatives $ 43,697 $ 47,170 $ 64,819 Interest Rate Swaps Net realized gains (losses) on derivatives (1) (31,593 ) (88,722 ) (146,173 ) Mortgage Options Net unrealized gains (losses) on derivatives — — 225 Mortgage Options Net realized gains (losses) on derivatives — — 443 Treasury Futures Net unrealized gains (losses) on derivatives 1,768 378 8,634 Treasury Futures Net realized gains (losses) on derivatives (4,061 ) (9,170 ) (35,523 ) Swaptions Net unrealized gains (losses) on derivatives 2,511 2,545 (6,294 ) Swaptions Net realized gains (losses) on derivatives (6,134 ) (7,044 ) (353 ) Other Derivative Assets Net unrealized gains (losses) on derivatives — — — Other Derivative Assets Net realized gains (losses) on derivatives — (566 ) (415 ) Total $ 6,188 $ (55,409 ) $ (114,637 ) (1) Includes loss on termination of interest rate swap of $16 million , $61 million , and $99 million for the years ended December 31, 2017 , 2016 , and 2015 respectively.

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Earnings Per Share	Earnings per share for the years ended December 31, 2017 , 2016 , and 2015 respectively, are computed as follows: For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 (dollars in thousands) Numerator: Net income available to common shareholders $ 491,184 $ 549,494 $ 250,349 Effect of dilutive securities: — — — Dilutive net income available to common shareholders $ 491,184 $ 549,494 $ 250,349 Denominator: Weighted average basic shares 187,780,355 187,728,634 199,563,196 Effect of dilutive securities 506,965 296,204 86,981 Weighted average dilutive shares 188,287,320 188,024,838 199,650,177 Net income per average share attributable to common stockholders - Basic $ 2.62 $ 2.93 $ 1.25 Net income per average share attributable to common stockholders - Diluted $ 2.61 $ 2.92 $ 1.25

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Components of AOCI	The following table presents the changes in the components of Accumulated Other Comprehensive Income (“AOCI”) for the year ended December 31, 2017 and 2016 : December 31, 2017 (dollars in thousands) Unrealized gains (losses) on available-for-sale securities, net Total Accumulated OCI Balance Balance as of December 31, 2016 $ 718,106 $ 718,106 OCI before reclassifications 24,218 24,218 Amounts reclassified from AOCI 54,578 54,578 Net current period OCI 78,796 78,796 Balance as of December 31, 2017 $ 796,902 $ 796,902 December 31, 2016 (dollars in thousands) Unrealized gains (losses) on available-for-sale securities, net Total Accumulated OCI Balance Balance as of December 31, 2015 $ 773,791 $ 773,791 OCI before reclassifications (88,527 ) (88,527 ) Amounts reclassified from AOCI 32,842 32,842 Net current period OCI (55,685 ) (55,685 ) Balance as of December 31, 2016 $ 718,106 $ 718,106
Schedule of Reclassifications from AOCI	The following table presents the details of the reclassifications from AOCI for the year ended December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 Details about Accumulated OCI Components Amounts Reclassified from Accumulated OCI Amounts Reclassified from Accumulated OCI Affected Line on the Consolidated Statements Of Operations Unrealized gains and losses on available-for-sale securities $ 7,278 $ 25,145 Net realized gains (losses) on sales of investments (61,856 ) (57,987 ) Net other-than-temporary credit impairment losses $ (54,578 ) $ (32,842 ) Income before income taxes — — Income taxes $ (54,578 ) $ (32,842 ) Net of tax

Equity Compensation, Employme36

Equity Compensation, Employment Agreements and other Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Compensation Related Costs [Abstract]
Share-based Compensation, Performance Shares Award Nonvested Activity	The following table presents information with respect to the Company's stock awards during the years ended December 31, 2017 and 2016 . For the Year Ended December 31, 2017 December 31, 2016 Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Unvested shares outstanding - beginning of period 577,547 14.53 71,000 28.39 Granted 348,244 18.68 539,847 13.49 Vested (155,976 ) 30.74 (33,300 ) 27.23 Forfeited — — — — Unvested shares outstanding - end of period 769,815 25.58 577,547 14.53

Credit Risk and Interest Rate37

Credit Risk and Interest Rate Risk (Tables)	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Schedule of Assets and Liabilities Subject to Netting Arrangements	The following table presents information about our liabilities that are subject to such arrangements and can potentially be offset on our consolidated statements of financial condition as of December 31, 2017 and December 31, 2016 . December 31, 2017 (dollars in thousands) Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts Offset in the Consolidated Statements of Financial Position Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position Financial Instruments Cash Collateral (Received) Pledged (1) Net Amount Repurchase Agreements $ (7,250,452 ) $ — $ (7,250,452 ) $ 8,788,680 $ 1,156 $ 1,539,384 Interest Rate Swaps - Gross Assets 44,874 (1,617 ) 43,257 — 11,570 54,827 Interest Rate Swaps - Gross Liabilities (1,617 ) 1,617 — — — — Treasury Futures - Gross Assets 3,552 — 3,552 — 376 3,928 Treasury Futures - Gross Liabilities — — — — — — Swaptions - Gross Assets 2,105 — 2,105 — — 2,105 Swaptions - Gross Liabilities (320 ) — (320 ) — — (320 ) Total Liabilities $ (7,201,858 ) $ — $ (7,201,858 ) $ 8,788,680 $ 13,102 $ 1,599,924 (1) Included in other assets December 31, 2016 (dollars in thousands) Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts Offset in the Consolidated Statements of Financial Position Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position Financial Instruments Cash Collateral (Received) Pledged (1) Net Amount Repurchase Agreements $ (5,600,903 ) $ — $ (5,600,903 ) $ 7,033,866 $ 2,545 $ 1,435,508 Interest Rate Swaps - Gross Assets 14,435 (14,435 ) — — — — Interest Rate Swaps - Gross Liabilities (14,875 ) 14,875 — — 39,627 39,627 Treasury Futures - Gross Assets 1,785 — 1,785 — 3,320 5,105 Treasury Futures - Gross Liabilities — — — — — — Swaptions - Gross Assets 7,892 — 7,892 — — 7,892 Swaptions - Gross Liabilities (2,350 ) — (2,350 ) 10,341 — 7,991 Total Liabilities $ (5,594,016 ) $ 440 $ (5,593,576 ) $ 7,044,207 $ 45,492 $ 1,496,123 (1) Included in other assets

Summarized Quarterly Results 38

Summarized Quarterly Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	The following is a presentation of the results of operations for the quarters ended December 31, 2017, September 30, 2017, June 30, 2017 and March 31, 2017. For the Quarter Ended December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 (dollars in thousands, except per share data) Net Interest Income: Interest income $ 301,957 $ 296,813 $ 288,644 $ 251,344 Interest expense 144,204 140,358 137,955 110,231 Net interest income 157,753 156,455 150,689 141,113 Other-than-temporary impairments: Total other-than-temporary impairment losses (923 ) (784 ) (749 ) (2,713 ) Portion of loss recognized in other comprehensive income (17,256 ) (10,684 ) (12,760 ) (15,988 ) Net other-than-temporary credit impairment losses (18,179 ) (11,468 ) (13,509 ) (18,701 ) Net gains (losses) on derivatives 31,108 1,363 (21,822 ) (4,462 ) Net unrealized gains (losses) on financial instruments at fair value (47,637 ) 19,042 67,762 72,243 Net realized gains (losses) on sales of investments (586 ) 1 4,541 5,167 Gain (loss) on Extinguishment of Debt 12,742 (1 ) (48,014 ) — Total other expenses 27,657 26,142 24,491 32,537 Net income (loss) $ 107,608 $ 139,232 $ 115,017 $ 162,807 Dividend on preferred stock $ 9,400 $ 9,400 $ 9,400 $ 5,283 Net income (loss) available to common shareholders $ 98,208 $ 129,832 $ 105,617 $ 157,524 Net income per common share-basic $ 0.52 $ 0.69 $ 0.56 $ 0.84 The following is a presentation of the results of operations for the quarters ended December 31, 2016, September 30, 2016, June 30, 2016 and March 31, 2016. For the Quarter Ended December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 (dollars in thousands, except per share data) Net Interest Income: Interest income $ 260,823 $ 250,953 $ 221,096 $ 201,194 Interest expense 106,737 94,911 83,227 62,981 Net interest income 154,086 156,042 137,869 138,213 Other-than-temporary impairments: Total other-than-temporary impairment losses (1,034 ) (993 ) (3,129 ) (4,423 ) Portion of loss recognized in other comprehensive income (13,746 ) (10,581 ) (17,816 ) (6,255 ) Net other-than-temporary credit impairment losses (14,780 ) (11,574 ) (20,955 ) (10,678 ) Net gains (losses) on derivatives 115,523 13,360 (47,755 ) (136,537 ) Net unrealized gains (losses) on financial instruments at fair value (20,664 ) 32,999 30,347 16,871 Net realized gains (losses) on sales of investments 11,121 3,079 6,631 (2,674 ) Gain (loss) on Extinguishment of Debt 1,334 (45 ) — (1,766 ) Other Income — — — 95,000 Total other expenses 24,698 21,031 31,987 15,302 Net income (loss) $ 221,903 $ 172,817 $ 74,127 $ 83,098 Dividend on preferred stock $ 2,449 $ — $ — $ — Net income (loss) available to common shareholders $ 219,454 $ 172,817 $ 74,127 $ 83,098 Net income per common share-basic $ 1.17 $ 0.92 $ 0.39 $ 0.44

Organization - Narrative (Detai

Organization - Narrative (Detail)	12 Months Ended
	Dec. 31, 2017subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of wholly owned direct subsidiaries	8

Summary of the Significant Ac40

Summary of the Significant Accounting Policies (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	[1]
Investment [Line Items]
Non-Agency RMBS, at fair value	$ 2,851,316,000				$ 3,330,063,000				$ 2,851,316,000		$ 3,330,063,000
Agency MBS, at fair value	4,364,828,000				4,167,754,000				4,364,828,000		4,167,754,000
Interest income	301,957,000	$ 296,813,000	$ 288,644,000	$ 251,344,000	260,823,000	$ 250,953,000	$ 221,096,000	$ 201,194,000	1,138,758,000	[1]	934,068,000	[1]	$ 872,737,000
Penalties and interest accrued	0				0				0		0
Restricted cash	0								0
Securitized debt at fair value, collateralized by loans held for investment, fair value	9,388,657,000				6,941,097,000				9,388,657,000		6,941,097,000
Non-Agency RMBS
Investment [Line Items]
Non-Agency RMBS, at fair value	14,000,000				19,000,000				14,000,000		19,000,000
Residential Mortgage-Backed Securities | Interest-only
Investment [Line Items]
Interest income									31,000,000		43,000,000
Residential Mortgage-Backed Securities | Non-Agency RMBS - Interest-only | Interest-only
Investment [Line Items]
Non-Agency RMBS, at fair value	219,000,000				266,000,000				219,000,000		266,000,000
Residential Mortgage-Backed Securities | Agency MBS - Interest-only | Interest-only
Investment [Line Items]
Agency MBS, at fair value	104,000,000				145,000,000				104,000,000		145,000,000
Seasoned Subprime Residential Mortgage Loans | Loans Held for Investment at Fair Value
Investment [Line Items]
Real estate held-for-sale	$ 10,000,000				$ 13,000,000				$ 10,000,000		$ 13,000,000
[1]	Includes interest income of consolidated VIEs of $914,022, $678,623 and $575,715 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 8 to consolidated financial statements for further discussion.

Mortgage-Backed Securities - Su

Mortgage-Backed Securities - Summary (Detail) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Principal or Notional Value	$ 15,442,782	$ 17,062,076
Total Premium	563,428	662,686
Total Discount	(1,438,994)	(1,627,480)
Amortized Cost	6,481,537	6,825,525
Fair Value	7,216,144	7,497,817
Gross Unrealized Gains	861,182	841,967
Gross Unrealized Losses	(126,575)	(169,675)
Net Unrealized Gain/(Loss)	734,607	672,292
Non-Agency RMBS - Senior
Investment Holdings [Line Items]
Principal or Notional Value	2,733,926	3,190,947
Total Premium	540	231
Total Discount	(1,257,103)	(1,412,058)
Amortized Cost	1,477,363	1,779,120
Fair Value	2,231,415	2,511,003
Gross Unrealized Gains	754,234	732,133
Gross Unrealized Losses	(182)	(250)
Net Unrealized Gain/(Loss)	754,052	731,883
Non-Agency RMBS - Senior interest-only
Investment Holdings [Line Items]
Principal or Notional Value	4,862,461	5,648,339
Total Premium	262,996	292,396
Total Discount	0	0
Amortized Cost	262,996	292,396
Fair Value	210,850	253,539
Gross Unrealized Gains	15,761	18,674
Gross Unrealized Losses	(67,907)	(57,531)
Net Unrealized Gain/(Loss)	(52,146)	(38,857)
Non-Agency RMBS - Subordinated
Investment Holdings [Line Items]
Principal or Notional Value	501,455	673,259
Total Premium	10,571	16,352
Total Discount	(177,206)	(212,734)
Amortized Cost	334,820	476,877
Fair Value	401,225	553,498
Gross Unrealized Gains	66,704	77,857
Gross Unrealized Losses	(299)	(1,236)
Net Unrealized Gain/(Loss)	66,405	76,621
Non-Agency RMBS - Subordinated interest-only
Investment Holdings [Line Items]
Principal or Notional Value	201,378	266,927
Total Premium	7,369	13,878
Total Discount	0	0
Amortized Cost	7,369	13,878
Fair Value	7,826	12,024
Gross Unrealized Gains	902	0
Gross Unrealized Losses	(445)	(1,854)
Net Unrealized Gain/(Loss)	457	(1,854)
Agency MBS - Residential
Investment Holdings [Line Items]
Principal or Notional Value	2,227,128	2,594,570
Total Premium	123,245	149,872
Total Discount	0	0
Amortized Cost	2,350,373	2,744,442
Fair Value	2,322,180	2,705,978
Gross Unrealized Gains	5,706	11,235
Gross Unrealized Losses	(33,899)	(49,699)
Net Unrealized Gain/(Loss)	(28,193)	(38,464)
Agency MBS - Commercial
Investment Holdings [Line Items]
Principal or Notional Value	1,894,594	1,331,543
Total Premium	47,430	37,782
Total Discount	(4,685)	(2,688)
Amortized Cost	1,937,339	1,366,637
Fair Value	1,938,281	1,316,975
Gross Unrealized Gains	17,041	175
Gross Unrealized Losses	(16,099)	(49,837)
Net Unrealized Gain/(Loss)	942	(49,662)
Agency MBS - Interest-only
Investment Holdings [Line Items]
Principal or Notional Value	3,021,840	3,356,491
Total Premium	111,277	152,175
Total Discount	0	0
Amortized Cost	111,277	152,175
Fair Value	104,367	144,800
Gross Unrealized Gains	834	1,893
Gross Unrealized Losses	(7,744)	(9,268)
Net Unrealized Gain/(Loss)	$ (6,910)	$ (7,375)

Mortgage-Backed Securities - Ac

Mortgage-Backed Securities - Accretable Yield (Detail) - Available-for-sale Securities - Non-Agency RMBS Having Deteriorated Credit When Acquired - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 1,550,110	$ 1,742,744
Purchases	20,962	79,156
Yield income earned	(266,214)	(282,800)
Reclassification (to) from non-accretable difference	18,909	53,681
Sales and deconsolidation	(20,178)	(42,671)
Balance at end of period	$ 1,303,589	$ 1,550,110

Mortgage-Backed Securities - No

Mortgage-Backed Securities - Non-Agency Securities Having Deteriorated Credit When Acquired (Detail) - Non-Agency RMBS Having Deteriorated Credit When Acquired - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Outstanding principal balance:
Beginning of period	$ 3,138,265	$ 3,550,698
End of period	2,673,350	3,138,265
Amortized cost:
Beginning of period	1,695,079	1,958,726
End of period	$ 1,381,839	$ 1,695,079

Mortgage-Backed Securities - Un

Mortgage-Backed Securities - Unrealized Loss Positions (Detail) - Residential Mortgage-Backed Securities $ in Thousands	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)security
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 1,569,727	$ 3,815,885
Unrealized Loss Position for 12 Months or More	1,818,645	252,257
Total	3,388,372	4,068,142
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(19,477)	(110,548)
Unrealized Loss Position for 12 Months or More	(107,098)	(59,127)
Total	$ (126,575)	$ (169,675)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	239	846
Unrealized Loss Position for 12 Months or More | security	336	156
Total | security	575	1,002
Non-Agency RMBS - Senior
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 35,229	$ 12,384
Unrealized Loss Position for 12 Months or More	0	0
Total	35,229	12,384
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(182)	(250)
Unrealized Loss Position for 12 Months or More	0	0
Total	$ (182)	$ (250)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	1	3
Unrealized Loss Position for 12 Months or More | security	0	0
Total | security	1	3
Non-Agency RMBS - Senior interest-only
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 28,129	$ 96,399
Unrealized Loss Position for 12 Months or More	120,120	78,516
Total	148,249	174,915
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(1,724)	(13,600)
Unrealized Loss Position for 12 Months or More	(66,183)	(43,931)
Total	$ (67,907)	$ (57,531)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	27	62
Unrealized Loss Position for 12 Months or More | security	120	86
Total | security	147	148
Non-Agency RMBS - Subordinated
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 235	$ 56,015
Unrealized Loss Position for 12 Months or More	6,261	2,826
Total	6,496	58,841
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(38)	(412)
Unrealized Loss Position for 12 Months or More	(261)	(824)
Total	$ (299)	$ (1,236)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	7	7
Unrealized Loss Position for 12 Months or More | security	5	4
Total | security	12	11
Non-Agency RMBS - Subordinated interest-only
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 0	$ 748
Unrealized Loss Position for 12 Months or More	945	11,276
Total	945	12,024
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	0	(230)
Unrealized Loss Position for 12 Months or More	(445)	(1,624)
Total	$ (445)	$ (1,854)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	0	2
Unrealized Loss Position for 12 Months or More | security	3	3
Total | security	3	5
Agency MBS - Residential
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 660,103	$ 2,338,910
Unrealized Loss Position for 12 Months or More	1,471,464	54,943
Total	2,131,567	2,393,853
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(5,197)	(48,084)
Unrealized Loss Position for 12 Months or More	(28,702)	(1,615)
Total	$ (33,899)	$ (49,699)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	21	106
Unrealized Loss Position for 12 Months or More | security	93	1
Total | security	114	107
Agency MBS - Commercial
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 830,889	$ 1,247,923
Unrealized Loss Position for 12 Months or More	161,980	51,733
Total	992,869	1,299,656
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(11,695)	(45,802)
Unrealized Loss Position for 12 Months or More	(4,404)	(4,035)
Total	$ (16,099)	$ (49,837)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	176	646
Unrealized Loss Position for 12 Months or More | security	91	46
Total | security	267	692
Agency MBS - Interest-only
Estimated Fair Value
Unrealized Loss Position for Less than 12 Months	$ 15,142	$ 63,506
Unrealized Loss Position for 12 Months or More	57,875	52,963
Total	73,017	116,469
Unrealized Losses
Unrealized Loss Position for Less than 12 Months	(641)	(2,170)
Unrealized Loss Position for 12 Months or More	(7,103)	(7,098)
Total	$ (7,744)	$ (9,268)
Number of Securities
Unrealized Loss Position for Less than 12 Months | security	7	20
Unrealized Loss Position for 12 Months or More | security	24	16
Total | security	31	36

Mortgage-Backed Securities - In

Mortgage-Backed Securities - Investment Holdings - Narrative (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Interest-only
Investment Holdings [Line Items]
Interest-only RMBS, fair value	$ 323,000	$ 410,000
Interest-only RMBS, amortized cost	382,000	458,000
Interest-only RMBS, net unrealized gain (loss)	(59,000)	(48,000)
Agency RMBS - Pass-through
Investment Holdings [Line Items]
Gross unrealized loss	41,000	100,000
Non-agency MBS
Investment Holdings [Line Items]
Gross unrealized loss	$ 283	$ 485
Non-Agency RMBS Deemed To Be Equivalent To Alt-A Quality
Investment Holdings [Line Items]
Percentage in Alt-A collateral	66.00%	68.00%
Non Agency Residential MBS Deemed To Be Equivalent To Prime Quality
Investment Holdings [Line Items]
Percentage in prime collateral	13.00%	14.00%
Re-REMIC Security
Investment Holdings [Line Items]
Fair value of securities exchanged	$ 63,000	$ 65,000	$ 95,000
Gain (loss) on sale of investments	$ 9,000	$ 13,000	$ 24,000
Minimum | Alt-A
Investment Holdings [Line Items]
FICO Score	680
Maximum | Alt-A
Investment Holdings [Line Items]
FICO Score	720
Alt-A securities underlying collateral of full documented loans	30.00%

Mortgage-Backed Securities - Ag

Mortgage-Backed Securities - Aggregate Other Than Temporary Impairments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Total other-than-temporary impairment losses	$ (923)	$ (784)	$ (749)	$ (2,713)	$ (1,034)	$ (993)	$ (3,129)	$ (4,423)
Portion of loss recognized in other comprehensive income (loss)	$ (17,256)	$ (10,684)	$ (12,760)	$ (15,988)	$ (13,746)	$ (10,581)	$ (17,816)	$ (6,255)
Residential Mortgage-Backed Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Total other-than-temporary impairment losses									$ (5,169)	$ (9,589)	$ (8,700)
Portion of loss recognized in other comprehensive income (loss)									(56,687)	(48,398)	(58,744)
Net other-than-temporary credit impairment losses									$ (61,856)	$ (57,987)	$ (67,444)

Mortgage-Backed Securities - 47

Mortgage-Backed Securities - Non-Agency Securities Credit Losses (Detail) - Non-agency MBS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Cumulative credit loss beginning balance	$ 556,485	$ 529,112	$ 507,548
Additions:
Other-than-temporary impairments not previously recognized	12,669	25,959	41,233
Reductions for securities sold or deconsolidated during the period	(12,405)	(9,429)	(19,746)
Increases related to other-than-temporary impairments on securities with previously recognized other-than-temporary impairments	47,211	32,027	26,138
Reductions for increases in cash flows expected to be collected over the remaining life of the securities	(12,439)	(21,184)	(26,061)
Cumulative credit impairment loss ending balance	$ 591,521	$ 556,485	$ 529,112

Mortgage-Backed Securities - OT

Mortgage-Backed Securities - OTTI - Significant Inputs and Assumptions (Detail) - Non-agency MBS	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Weighted Average
Investment Holdings [Line Items]
Loss Severity	64.00%	58.00%
60 days delinquent	21.00%	21.00%
Credit Enhancement	16.00%	25.00%
3 Month CPR	10.00%	7.00%
12 Month CPR	11.00%	6.00%
Minimum
Investment Holdings [Line Items]
Loss Severity	28.00%	25.00%
60 days delinquent	11.00%	0.00%
Credit Enhancement	0.00%	0.00%
3 Month CPR	0.00%	0.00%
12 Month CPR	1.00%	1.00%
Maximum
Investment Holdings [Line Items]
Loss Severity	89.00%	85.00%
60 days delinquent	27.00%	40.00%
Credit Enhancement	50.00%	100.00%
3 Month CPR	24.00%	27.00%
12 Month CPR	19.00%	24.00%

Mortgage-Backed Securities - Gr

Mortgage-Backed Securities - Gross Unrealized Gains (Losses) (Detail) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	$ 838,391	$ 818,127
Gross Unrealized Gain Included in Cumulative Earnings	22,791	23,840
Total Gross Unrealized Gain	861,182	841,967
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(41,489)	(100,021)
Gross Unrealized Loss Included in Cumulative Earnings	(85,086)	(69,654)
Total Gross Unrealized Loss	(126,575)	(169,675)
Non-Agency RMBS - Senior
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	754,234	732,133
Gross Unrealized Gain Included in Cumulative Earnings	0	0
Total Gross Unrealized Gain	754,234	732,133
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(182)	(250)
Gross Unrealized Loss Included in Cumulative Earnings	0	0
Total Gross Unrealized Loss	(182)	(250)
Non-Agency RMBS - Senior interest-only
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	15,761	18,674
Total Gross Unrealized Gain	15,761	18,674
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(67,907)	(57,531)
Total Gross Unrealized Loss	(67,907)	(57,531)
Non-Agency RMBS - Subordinated
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	62,989	74,584
Gross Unrealized Gain Included in Cumulative Earnings	3,715	3,273
Total Gross Unrealized Gain	66,704	77,857
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(102)	(235)
Gross Unrealized Loss Included in Cumulative Earnings	(197)	(1,001)
Total Gross Unrealized Loss	(299)	(1,236)
Non-Agency RMBS - Subordinated interest-only
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	902	0
Total Gross Unrealized Gain	902	0
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(445)	(1,854)
Total Gross Unrealized Loss	(445)	(1,854)
Agency MBS - Residential
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	5,706	11,235
Gross Unrealized Gain Included in Cumulative Earnings	0	0
Total Gross Unrealized Gain	5,706	11,235
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(29,083)	(49,699)
Gross Unrealized Loss Included in Cumulative Earnings	(4,816)	0
Total Gross Unrealized Loss	(33,899)	(49,699)
Agency MBS - Commercial
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	15,462	175
Gross Unrealized Gain Included in Cumulative Earnings	1,579	0
Total Gross Unrealized Gain	17,041	175
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(12,122)	(49,837)
Gross Unrealized Loss Included in Cumulative Earnings	(3,977)	0
Total Gross Unrealized Loss	(16,099)	(49,837)
Agency MBS - Interest-only
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	834	1,893
Total Gross Unrealized Gain	834	1,893
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(7,744)	(9,268)
Total Gross Unrealized Loss	$ (7,744)	$ (9,268)

Mortgage-Backed Securities - Co

Mortgage-Backed Securities - Collateral Characteristics (Detail) - Residential Mortgage-Backed Securities $ in Thousands	Dec. 31, 2017USD ($)$ / security	Dec. 31, 2016USD ($)$ / security
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 15,442,782	$ 17,062,076
Non-Agency RMBS - Senior
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 2,733,926	$ 3,190,947
Weighted Average Amortized Cost Basis	54.04	55.76
Weighted Average Fair Value	81.62	78.69
Weighted Average Coupon	4.60%	4.30%
Weighted Average Yield at Period-End	16.70%	15.50%
Non-Agency RMBS - Senior interest-only
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 4,862,461	$ 5,648,339
Weighted Average Amortized Cost Basis	5.41	5.18
Weighted Average Fair Value	4.34	4.49
Weighted Average Coupon	1.30%	1.50%
Weighted Average Yield at Period-End	8.00%	11.70%
Non-Agency RMBS - Subordinated
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 501,455	$ 673,259
Weighted Average Amortized Cost Basis	66.77	70.83
Weighted Average Fair Value	80.01	82.21
Weighted Average Coupon	4.10%	3.80%
Weighted Average Yield at Period-End	9.60%	9.20%
Non-Agency RMBS - Subordinated interest-only
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 201,378	$ 266,927
Weighted Average Amortized Cost Basis	3.66	5.20
Weighted Average Fair Value	3.89	4.50
Weighted Average Coupon	0.80%	1.10%
Weighted Average Yield at Period-End	11.80%	13.50%
Agency MBS - Residential
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 2,227,128	$ 2,594,570
Weighted Average Amortized Cost Basis	105.53	105.78
Weighted Average Fair Value	104.27	104.29
Weighted Average Coupon	3.80%	3.90%
Weighted Average Yield at Period-End	2.90%	3.00%
Agency MBS - Commercial
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 1,894,594	$ 1,331,543
Weighted Average Amortized Cost Basis	102.26	102.64
Weighted Average Fair Value	102.31	98.91
Weighted Average Coupon	3.60%	3.60%
Weighted Average Yield at Period-End	3.20%	2.90%
Agency MBS - Interest-only
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 3,021,840	$ 3,356,491
Weighted Average Amortized Cost Basis	3.68	4.53
Weighted Average Fair Value	3.45	4.31
Weighted Average Coupon	0.70%	0.80%
Weighted Average Yield at Period-End	3.40%	3.50%

Mortgage-Backed Securities - Cr

Mortgage-Backed Securities - Credit Ratings (Detail) - Non-agency MBS	Dec. 31, 2017	Dec. 31, 2016
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	100.00%	100.00%
AAA
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	0.30%	0.30%
AA
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	0.30%	0.30%
A
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	0.60%	0.70%
BBB
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	1.90%	0.70%
BB
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	2.50%	3.00%
B
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	2.30%	3.90%
Below B
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	59.60%	67.20%
Not Rated
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	32.50%	23.90%

Mortgage-Backed Securities - Ma

Mortgage-Backed Securities - Maturities (Detail) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair value
Less than one year, at fair value	$ 2,198	$ 26,029
Greater than one year and less than five years, at fair value	959,890	1,194,654
Greater than five years and less than ten years, at fair value	3,447,385	3,990,091
Greater than ten years, at fair value	2,806,671	2,287,043
Total maturities, at fair value	7,216,144	7,497,817
Amortized cost
Less than one year, at amortized cost	3,395	23,415
Greater than one year and less than five years, at amortized cost	784,660	1,094,684
Greater than five years and less than ten years, at amortized cost	3,128,723	3,605,434
Greater than ten years, at amortized cost	2,564,759	2,101,992
Amortized Cost	6,481,537	6,825,525
Non-Agency RMBS - Senior
Fair value
Less than one year, at fair value	2,179	25,612
Greater than one year and less than five years, at fair value	681,086	508,979
Greater than five years and less than ten years, at fair value	910,234	1,267,000
Greater than ten years, at fair value	637,916	709,412
Total maturities, at fair value	2,231,415	2,511,003
Amortized cost
Less than one year, at amortized cost	2,124	21,423
Greater than one year and less than five years, at amortized cost	493,965	403,250
Greater than five years and less than ten years, at amortized cost	569,458	868,624
Greater than ten years, at amortized cost	411,816	485,823
Amortized Cost	1,477,363	1,779,120
Non-Agency RMBS - Senior interest-only
Fair value
Less than one year, at fair value	19	417
Greater than one year and less than five years, at fair value	54,107	37,796
Greater than five years and less than ten years, at fair value	72,702	115,780
Greater than ten years, at fair value	84,022	99,546
Total maturities, at fair value	210,850	253,539
Amortized cost
Less than one year, at amortized cost	1,271	1,992
Greater than one year and less than five years, at amortized cost	73,758	50,252
Greater than five years and less than ten years, at amortized cost	94,145	134,642
Greater than ten years, at amortized cost	93,822	105,510
Amortized Cost	262,996	292,396
Non-Agency RMBS - Subordinated
Fair value
Less than one year, at fair value	0	0
Greater than one year and less than five years, at fair value	75,495	94,793
Greater than five years and less than ten years, at fair value	121,555	238,630
Greater than ten years, at fair value	204,175	220,075
Total maturities, at fair value	401,225	553,498
Amortized cost
Less than one year, at amortized cost	0	0
Greater than one year and less than five years, at amortized cost	61,987	76,287
Greater than five years and less than ten years, at amortized cost	91,044	195,538
Greater than ten years, at amortized cost	181,789	205,052
Amortized Cost	334,820	476,877
Non-Agency RMBS - Subordinated interest-only
Fair value
Less than one year, at fair value	0	0
Greater than one year and less than five years, at fair value	7,165	0
Greater than five years and less than ten years, at fair value	661	12,024
Greater than ten years, at fair value	0	0
Total maturities, at fair value	7,826	12,024
Amortized cost
Less than one year, at amortized cost	0	0
Greater than one year and less than five years, at amortized cost	6,355	0
Greater than five years and less than ten years, at amortized cost	1,014	13,878
Greater than ten years, at amortized cost	0	0
Amortized Cost	7,369	13,878
Agency MBS - Residential
Fair value
Less than one year, at fair value	0	0
Greater than one year and less than five years, at fair value	21,777	429,869
Greater than five years and less than ten years, at fair value	2,300,403	2,276,109
Greater than ten years, at fair value	0	0
Total maturities, at fair value	2,322,180	2,705,978
Amortized cost
Less than one year, at amortized cost	0	0
Greater than one year and less than five years, at amortized cost	22,069	438,270
Greater than five years and less than ten years, at amortized cost	2,328,304	2,306,172
Greater than ten years, at amortized cost	0	0
Amortized Cost	2,350,373	2,744,442
Agency MBS - Commercial
Fair value
Less than one year, at fair value	0	0
Greater than one year and less than five years, at fair value	45,770	47,354
Greater than five years and less than ten years, at fair value	16,559	16,833
Greater than ten years, at fair value	1,875,952	1,252,788
Total maturities, at fair value	1,938,281	1,316,975
Amortized cost
Less than one year, at amortized cost	0	0
Greater than one year and less than five years, at amortized cost	47,170	49,027
Greater than five years and less than ten years, at amortized cost	17,176	17,247
Greater than ten years, at amortized cost	1,872,993	1,300,363
Amortized Cost	1,937,339	1,366,637
Agency MBS - Interest-only
Fair value
Less than one year, at fair value	0	0
Greater than one year and less than five years, at fair value	74,490	75,863
Greater than five years and less than ten years, at fair value	25,271	63,715
Greater than ten years, at fair value	4,606	5,222
Total maturities, at fair value	104,367	144,800
Amortized cost
Less than one year, at amortized cost	0	0
Greater than one year and less than five years, at amortized cost	79,356	77,598
Greater than five years and less than ten years, at amortized cost	27,582	69,333
Greater than ten years, at amortized cost	4,339	5,244
Amortized Cost	$ 111,277	$ 152,175

Mortgage-Backed Securities - Ge

Mortgage-Backed Securities - Geographical and Other Statistics (Detail) - Non-agency MBS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Weighted average maturity (years)	20 years 8 months 12 days	21 years 7 months 6 days
Weighted average amortized loan to value	64.40%	66.50%
Weighted average FICO	697	698
Weighted average loan balance (in thousands)	$ 314	$ 319
Weighted average percentage owner occupied	84.40%	83.20%
Weighted average percentage single family residence	66.30%	65.80%
Weighted average current credit enhancement	2.20%	2.30%
California
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	31.70%	32.10%
New York
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	8.50%	7.90%
Florida
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	8.30%	8.10%
New Jersey
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	2.70%	2.70%

Mortgage-Backed Securities - Ye

Mortgage-Backed Securities - Year Originated (Detail) - Non-agency MBS	Dec. 31, 2017	Dec. 31, 2016
Origination Year as a Percentage of Outstanding Principal Balance:
2003 (and prior)	3.60%	3.60%
2,004	4.30%	4.20%
2,005	20.80%	20.20%
2,006	38.20%	38.00%
2,007	30.40%	31.30%
2,008	1.80%	1.80%
2009 and later	0.90%	0.90%
Total	100.00%	100.00%

Mortgage-Backed Securities - Ga

Mortgage-Backed Securities - Gains and Losses from Sales of Investments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales									$ 812,005	$ 2,719,329	$ 6,244,613
Gross realized gains									17,538	28,572	94,618
Gross realized losses									(8,415)	(10,417)	(17,544)
Net realized gain (loss)	$ (586)	$ 1	$ 4,541	$ 5,167	$ 11,121	$ 3,079	$ 6,631	$ (2,674)	$ 9,123	$ 18,155	$ 77,074

Loans Held for Investment - Nar

Loans Held for Investment - Narrative (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Securitized debt loans held for investment at cost	$ 13,300,000	$ 8,600,000
90 and over days delinquent	752,967	548,843
Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
90 and over days delinquent	577,000	449,000
Loans Held for Investment at Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Foreclosure	200,000	203,000
Bankruptcy	273,000	207,000
REO	$ 31,000	$ 41,000

Loans Held for Investment - Rol

Loans Held for Investment - Roll-Forward (Detail) - Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure - Loans Held for Investment at Fair Value - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance, beginning of period	$ 8,753,653	$ 4,768,416
Purchases	6,539,765	4,897,370
Principal paydowns	(1,788,409)	(1,022,414)
Sales and settlements	2,876	5,007
Net periodic accretion (amortization)	(35,803)	(41,363)
Change in fair value	206,181	146,637
Balance, end of period	$ 13,678,263	$ 8,753,653

Loans Held for Investment - Yea

Loans Held for Investment - Year Originated (Detail) - Loans Held for Investment at Fair Value - Seasoned Subprime Residential Mortgage Loans	Dec. 31, 2017	Dec. 31, 2016
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
2002 and prior	7.50%	8.90%
2,003	6.70%	5.20%
2,004	14.60%	11.90%
2,005	20.40%	20.50%
2,006	23.10%	22.00%
2,007	19.00%	20.90%
2,008	6.00%	6.50%
2,009	0.70%	0.60%
2010 and later	2.00%	3.50%
Total	100.00%	100.00%

Loans Held for Investment - Col

Loans Held for Investment - Collateral Characteristics (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans	149,172	95,155,000
Loans Held for Investment at Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans	149,172	95,155
Weighted average maturity (years)	18 years 9 months 18 days	19 years 9 months 18 days
Weighted average loan to value	88.00%	86.90%
Weighted average FICO	631	627
Weighted average loan balance (in thousands) | $	$ 91	$ 93
Weighted average percentage owner occupied	95.00%	96.60%
Weighted average percentage single family residence	86.00%	85.00%
Loans Held for Investment at Fair Value | California | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	9.00%	10.00%
Loans Held for Investment at Fair Value | Florida | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	7.20%	6.70%
Loans Held for Investment at Fair Value | Ohio | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	6.10%	6.50%
Loans Held for Investment at Fair Value | Pennsylvania | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	5.60%
Loans Held for Investment at Fair Value | Virginia | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	5.50%	5.90%
Loans Held for Investment at Fair Value | North Carolina | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states		5.10%

Loans Held for Investment - Loa

Loans Held for Investment - Loan Products Type and Characteristics (Details) $ in Thousands	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	149,172	95,155,000
Total Principal	$ 13,525,820	$ 8,868,783
30-89 Days Delinquent	1,286,215	844,044
90 Days Delinquent	$ 752,967	$ 548,843
Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	9,840	6,932,000
Total Principal	$ 1,058,863	$ 795,772
30-89 Days Delinquent	121,744	94,326
90 Days Delinquent	$ 61,744	$ 35,345
Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	1	7,000
Total Principal	$ 702	$ 3,468
30-89 Days Delinquent	0	97
90 Days Delinquent	$ 0	$ 0
Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	139,331	88,216,000
Total Principal	$ 12,466,255	$ 8,069,543
30-89 Days Delinquent	1,164,471	749,621
90 Days Delinquent	$ 691,223	$ 513,498
$1 to $250 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	9,227	6,417,000
Total Principal	$ 827,020	$ 609,584
30-89 Days Delinquent	95,952	67,705
90 Days Delinquent	$ 46,343	$ 25,102
$1 to $250 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan		2,000
Total Principal		$ 190
30-89 Days Delinquent		97
90 Days Delinquent		$ 0
$1 to $250 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	133,437	83,925,000
Total Principal	$ 10,371,829	$ 6,487,251
30-89 Days Delinquent	960,564	603,388
90 Days Delinquent	$ 562,271	$ 424,980
$250 to $500 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	529	458,000
Total Principal	$ 171,266	$ 147,410
30-89 Days Delinquent	19,289	22,821
90 Days Delinquent	$ 11,855	$ 7,684
$250 to $500 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan		1,000
Total Principal		$ 496
30-89 Days Delinquent		0
90 Days Delinquent		$ 0
$250 to $500 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	5,324	3,769,000
Total Principal	$ 1,713,839	$ 1,225,999
30-89 Days Delinquent	188,257	136,702
90 Days Delinquent	$ 114,616	$ 80,984
$500 to $750 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	67	45,000
Total Principal	$ 39,212	$ 26,383
30-89 Days Delinquent	3,041	3,033
90 Days Delinquent	$ 2,382	$ 1,131
$500 to $750 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	1	3,000
Total Principal	$ 702	$ 1,842
30-89 Days Delinquent	0	0
90 Days Delinquent	$ 0	$ 0
$500 to $750 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	440	381,000
Total Principal	$ 258,058	$ 223,638
30-89 Days Delinquent	12,789	9,531
90 Days Delinquent	$ 13,459	$ 5,788
$750 to $1,000 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	9	7,000
Total Principal	$ 7,663	$ 5,754
30-89 Days Delinquent	757	768
90 Days Delinquent	$ 0	$ 0
$750 to $1,000 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan		1,000
Total Principal		$ 940
30-89 Days Delinquent		0
90 Days Delinquent		$ 0
$750 to $1,000 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	99	103,000
Total Principal	$ 84,701	$ 87,680
30-89 Days Delinquent	1,706	0
90 Days Delinquent	$ 877	$ 1,746
Over $1,000 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	8	5,000
Total Principal	$ 13,702	$ 6,641
30-89 Days Delinquent	2,705	0
90 Days Delinquent	$ 1,164	$ 1,428
Over $1,000 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	31	38,000
Total Principal	$ 37,828	$ 44,975
30-89 Days Delinquent	1,155	0
90 Days Delinquent	$ 0	$ 0
Minimum | $1 to $250
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate		6.67%
Minimum | $1 to $250 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	1.00%	1.38%
Minimum | $1 to $250 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	0.00%	0.00%
Minimum | $250 to $500
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate		5.88%
Minimum | $250 to $500 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	2.00%	2.13%
Minimum | $250 to $500 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	0.00%	0.00%
Minimum | $500 to $750 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	2.00%	2.00%
Minimum | $500 to $750 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	6.88%	5.63%
Minimum | $500 to $750 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	2.00%	2.00%
Minimum | $750 to $1,000 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	3.88%	3.13%
Minimum | $750 to $1,000 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate		5.75%
Minimum | $750 to $1,000 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	2.00%	3.75%
Minimum | Over $1,000 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	3.88%	3.13%
Minimum | Over $1,000 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	3.00%	3.25%
Maximum | $1 to $250
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate		6.83%
Maximum | $1 to $250 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	18.74%	15.20%
Maximum | $1 to $250 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	24.00%	24.00%
Maximum | $250 to $500
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate		5.88%
Maximum | $250 to $500 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	11.88%	10.00%
Maximum | $250 to $500 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	12.52%	12.52%
Maximum | $500 to $750 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	9.25%	9.25%
Maximum | $500 to $750 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	6.88%	6.88%
Maximum | $500 to $750 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	10.69%	10.69%
Maximum | $750 to $1,000 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	5.55%	5.17%
Maximum | $750 to $1,000 | Hybrid loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate		5.75%
Maximum | $750 to $1,000 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	7.69%	7.29%
Maximum | Over $1,000 | Adjustable rate loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	4.00%	3.38%
Maximum | Over $1,000 | Fixed loans:
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Interest Rate	5.75%	7.13%

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details)	12 Months Ended
	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Investments with Difference Between Model Price and Third-Party Price | Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans internally valued lower than third party prices | loan	4	10
Excess (deficit) of third party prices over internally developed price	$ (3,000,000)	$ 16,000,000
Investments with Difference Between Model Price and Third-Party Price | Securitized Loans Held For Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Excess (deficit) of third party prices over internally developed price		50,000,000
Internal Assessment | Investments with Difference Between Model Price and Third-Party Price | Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	25,000,000	123,000,000
Internal Assessment | Investments with Difference Between Model Price and Third-Party Price | Securitized Loans Held For Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	0	1,600,000,000
Third Party Assessment | Investments with Difference Between Model Price and Third-Party Price | Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	28,000,000	107,000,000
Third Party Assessment | Investments with Difference Between Model Price and Third-Party Price | Securitized Loans Held For Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value		1,550,000,000
Non-agency MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers in to Level 3 assets	$ 6,112,000	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Unpaid Principal, Fair Value and Impact of Changes in Fair Value on Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Assets:
Loans held for investment, at fair value	$ 13,678,263	$ 8,753,653	$ 13,678,263	$ 8,753,653
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment, fair value	9,388,657	6,941,097	9,388,657	6,941,097
Non-agency RMBS | Subordinated
Assets:
Fair Value	13,993	18,602	13,993	18,602
Gain (Loss) on Change in Fair Value	(545)	(1,983)	1,246	5,568
Non-agency RMBS | Senior, interest-only
Assets:
Unpaid Principal/ Notional	4,862,461	5,648,339	4,862,461	5,648,339
Fair Value	210,850	253,539	210,850	253,539
Gain (Loss) on Change in Fair Value	3,156	(26,844)	(13,290)	(4,512)
Non-agency RMBS | Subordinated, interest-only
Assets:
Unpaid Principal/ Notional	201,378	266,927	201,378	266,927
Fair Value	7,826	12,024	7,826	12,024
Gain (Loss) on Change in Fair Value	1,836	(1,169)	2,311	2,118
Agency MBS | Residential Pass-through
Assets:
Unpaid Principal/ Notional	577,522		577,522
Fair Value	602,829		602,829
Gain (Loss) on Change in Fair Value	(2,359)		(4,816)
Agency MBS | Commercial Pass-through
Assets:
Unpaid Principal/ Notional	564,379		564,379
Fair Value	570,105		570,105
Gain (Loss) on Change in Fair Value	(546)		(2,398)
Agency MBS | Interest-only
Assets:
Unpaid Principal/ Notional	3,021,840	3,356,491	3,021,840	3,356,491
Fair Value	104,367	144,800	104,367	144,800
Gain (Loss) on Change in Fair Value	(367)	(920)	465	(490)
Loans held for investment
Assets:
Gain (Loss) on Change in Fair Value	(65,643)	32,991	206,181	146,635
Loans held for investment, Unpaid Principal/Notional	13,525,820	8,868,783	13,525,820	8,868,783
Loans held for investment, at fair value	13,678,263	8,753,653	13,678,263	8,753,653
Securitized debt
Assets:
Gain (Loss) on Change in Fair Value	16,831	(22,738)	(78,289)	(89,767)
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment, Unpaid Principal/Notional	9,395,854	7,059,265	9,395,854	7,059,265
Securitized debt at fair value, collateralized by loans held for investment, fair value	$ 9,388,657	$ 6,941,097	$ 9,388,657	$ 6,941,097

Fair Value Measurements - Level

Fair Value Measurements - Level of Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Non-Agency RMBS, at fair value	$ 2,851,316	$ 3,330,063
Agency MBS, at fair value	4,364,828	4,167,754
Loans held for investment, at fair value	13,678,263	8,753,653
Derivatives, at fair value, net	48,914	9,677
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	(9,388,657)	(6,941,097)
Derivative, Total	(320)	(2,350)
Fair Value, Measurements, Recurring
Assets:
Non-Agency RMBS, at fair value	2,851,316	3,330,063
Agency MBS, at fair value	4,364,828	4,167,754
Loans held for investment, at fair value	13,678,263	8,753,653
Counterparty and Cash Collateral, netting	(1,617)	(14,435)
Derivatives, at fair value, net	48,914	9,677
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	(9,388,657)	(6,941,097)
Counterparty and Cash Collateral, netting	1,617	14,875
Derivative, Total	(320)	(2,350)
Fair Value, Measurements, Recurring | Level 1
Assets:
Non-Agency RMBS, at fair value	0	0
Agency MBS, at fair value	0	0
Loans held for investment, at fair value	0	0
Derivatives	3,553	1,785
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	0	0
Derivatives	0	0
Fair Value, Measurements, Recurring | Level 2
Assets:
Non-Agency RMBS, at fair value	0	0
Agency MBS, at fair value	4,364,828	4,167,754
Loans held for investment, at fair value	0	0
Derivatives	46,978	22,327
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	0	0
Derivatives	(1,937)	(17,225)
Fair Value, Measurements, Recurring | Level 3
Assets:
Non-Agency RMBS, at fair value	2,851,316	3,330,063
Agency MBS, at fair value	0	0
Loans held for investment, at fair value	13,678,263	8,753,653
Derivatives	0	0
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	(9,388,657)	(6,941,097)
Derivatives	$ 0	$ 0

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Input Reconciliation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Securitized Debt | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Fair Value, Assets Measured on Recurring Basis [Roll Forward]
Other than temporary credit impairment losses	$ 0	$ 0
Realized gains (losses) on sales and settlements	(35,273)	(122)
Net unrealized gains (losses) included in income	(78,289)	(89,766)
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]
Securitized Debt, Beginning balance, Level 3	(6,941,097)	(3,720,496)
Securitized Debt, Transfers in to Level 3 assets	0	0
Securitized Debt, Transfers out of Level 3 assets	0	0
Securitized Debt, Purchases	(5,173,430)	(4,797,255)
Securitized Debt, Principal payments	1,787,368	1,059,854
Securitized Debt, Sales and Settlements	1,056,765	608,816
Securitized Debt, Accretion (amortization) of purchase discounts	(4,701)	(2,128)
Securitized Debt, Gains (losses) included in other comprehensive income	0	0
Securitized Debt, Ending balance, Level 3	(9,388,657)	(6,941,097)
Non-agency MBS
Fair Value, Assets Measured on Recurring Basis [Roll Forward]
Beginning balance Level 3 assets	3,330,063	3,675,841
Transfers in to Level 3 assets	6,112	0
Transfers out of Level 3 assets	0	0
Purchases	78,400	257,914
Principal payments	(568,339)	(532,696)
Sales and settlements	(68,162)	(149,938)
Accretion (amortization) of purchase discounts	120,119	120,638
Other than temporary credit impairment losses	(59,881)	(57,986)
Realized gains (losses) on sales and settlements	12,031	13,761
Net unrealized gains (losses) included in income	(9,733)	3,173
Total unrealized gains (losses) for the period	10,706	(644)
Ending balance Level 3 assets	2,851,316	3,330,063
Loans held for investment | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Fair Value, Assets Measured on Recurring Basis [Roll Forward]
Beginning balance Level 3 assets	8,753,653	4,768,416
Transfers in to Level 3 assets	0	0
Transfers out of Level 3 assets	0	0
Purchases	6,539,765	4,897,370
Principal payments	(1,788,409)	(1,022,414)
Sales and settlements	2,876	5,007
Accretion (amortization) of purchase discounts	(35,803)	(41,363)
Other than temporary credit impairment losses	0	0
Realized gains (losses) on sales and settlements	0	0
Net unrealized gains (losses) included in income	206,181	146,637
Total unrealized gains (losses) for the period	0	0
Ending balance Level 3 assets	$ 13,678,263	$ 8,753,653

Fair Value Measurements - Uno65

Fair Value Measurements - Unobservable Input Reconciliation - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Non-agency MBS
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers in to Level 3 assets	$ 6,112	$ 0

Fair Value Measurements - Uno66

Fair Value Measurements - Unobservable Inputs Assumptions - Non-Agency RMBS Held for Investment (Detail) - Level 3	Dec. 31, 2017	Dec. 31, 2016
Non-Agency RMBS - Senior
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	4.40%	5.40%
Non-Agency RMBS - Senior interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	11.20%	12.50%
Non-Agency RMBS - Subordinated
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	5.80%	6.20%
Non-Agency RMBS - Subordinated interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	12.00%	13.20%
Minimum | Non-Agency RMBS - Senior
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	1.00%	1.00%
CDR	0.00%	0.00%
Loss Severity	35.00%	35.00%
Minimum | Non-Agency RMBS - Senior interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	3.00%	3.00%
CDR	0.00%	0.00%
Loss Severity	35.00%	35.00%
Minimum | Non-Agency RMBS - Subordinated
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	1.00%	1.00%
CDR	0.00%	0.00%
Loss Severity	35.00%	0.00%
Minimum | Non-Agency RMBS - Subordinated interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	6.00%	6.00%
CDR	0.00%	0.00%
Loss Severity	35.00%	35.00%
Maximum | Non-Agency RMBS - Senior
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	45.00%	35.00%
CDR	55.00%	22.00%
Loss Severity	89.00%	95.00%
Maximum | Non-Agency RMBS - Senior interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	25.00%	30.00%
CDR	50.00%	22.00%
Loss Severity	95.00%	95.00%
Maximum | Non-Agency RMBS - Subordinated
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	20.00%	25.00%
CDR	33.00%	18.00%
Loss Severity	69.00%	79.00%
Maximum | Non-Agency RMBS - Subordinated interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	22.00%	15.00%
CDR	9.00%	11.00%
Loss Severity	63.00%	76.00%

Fair Value Measurements - Uno67

Fair Value Measurements - Unobservable Inputs Assumptions - Securitized Debt (Detail)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Minimum | Level 3 | Securitized Debt at Fair Value, Collateralized by Loans Held for Investment
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Securitized debt at fair value, collateralized by loans held for investment, CPR Range	6.00%	1.00%
Securitized debt at fair value, collateralized by loans held for investment, CDR Range	0.00%	0.00%
Securitized debt at fair value, collateralized by loans held for investment, Loss Severity Range	35.00%	35.00%
Maximum | Level 3 | Securitized Debt at Fair Value, Collateralized by Loans Held for Investment
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Securitized debt at fair value, collateralized by loans held for investment, CPR Range	15.00%	35.00%
Securitized debt at fair value, collateralized by loans held for investment, CDR Range	6.00%	30.00%
Securitized debt at fair value, collateralized by loans held for investment, Loss Severity Range	60.00%	65.00%
Loans held for investment | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure | Securitized Loans
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Weighted Average Discount Rate			4.10%	4.40%

Fair Value Measurements - Uno68

Fair Value Measurements - Unobservable Inputs Assumptions - Loans Held for Investment (Detail) - Loans Held for Investment at Fair Value - Level 3	Dec. 31, 2017	Dec. 31, 2016
Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Coupon	6.90%	7.10%
FICO	627	621
Loan-to-value (LTV)	88.00%	88.00%
Weighted Average | Single family
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	87.00%	86.00%
Weighted Average | Manufactured housing
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	4.00%	6.00%
Weighted Average | Multi-family/mixed use/other
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	9.00%	8.00%
Weighted Average | Owner Occupied
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	95.00%	97.00%
Weighted Average | Investor
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	1.00%	2.00%
Weighted Average | Secondary
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	4.00%	1.00%
Base Rate
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Coupon	4.80%	5.20%
FICO	636	632
Loan-to-value (LTV)	89.00%	87.00%

Fair Value Measurements - Carry

Fair Value Measurements - Carrying and Fair Values (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securitized debt, collateralized by Non-Agency RMBS	$ 205,780	$ 334,124
Carrying Amount | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Repurchase agreements	7,250,452	5,600,903
Carrying Amount | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securitized debt, collateralized by Non-Agency RMBS	205,780	334,124
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Repurchase agreements	7,269,193	5,619,385
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securitized debt, collateralized by Non-Agency RMBS	$ 192,259	$ 324,261

Repurchase Agreements - Outstan

Repurchase Agreements - Outstanding, Weighted Average Borrowing Rates, Weighted Average Remaining Maturities, Average Daily Balances and the Fair Value of Collateral Pledged (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	$ 7,250,452	$ 5,600,903
Repurchase Agreements | Agency MBS - Residential
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	3,202,056	3,087,734
Average balance of Repurchase agreements secured by:	$ 3,120,474	$ 4,159,651
Average borrowing rate of Repurchase agreements secured by:	1.47%	0.90%
Average remaining maturity of Repurchase agreements secured by:	28 days	32 days
Average original maturity of Repurchase agreements secured by:	87 days	112 days
MBS pledged as collateral at fair value on Repurchase agreements:	$ 3,450,123	$ 3,334,245
Repurchase Agreements | Non-agency MBS and Loans held for investment (in thousands)
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	4,048,396	2,513,169
Average balance of Repurchase agreements secured by:	$ 3,203,700	$ 2,322,683
Average borrowing rate of Repurchase agreements secured by:	3.41%	3.05%
Average remaining maturity of Repurchase agreements secured by:	93 days	98 days
Average original maturity of Repurchase agreements secured by:	123 days	155 days
MBS pledged as collateral at fair value on Repurchase agreements:	$ 5,338,557	$ 3,699,621
Repurchase Agreements | Residential Mortgage-Backed Securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	7,250,452	5,600,903
Average balance of Repurchase agreements secured by:	6,324,174	6,482,334
MBS pledged as collateral at fair value on Repurchase agreements:	$ 8,788,680	$ 7,033,866

Repurchase Agreements - Maturit

Repurchase Agreements - Maturities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	$ 7,250,452	$ 5,600,903
Overnight
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	0	0
1 to 29 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	4,745,342	2,947,604
30 to 59 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	1,206,769	958,956
60 to 89 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	592,865	407,625
90 to 119 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	0	559,533
Greater than or equal to 120 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	$ 705,476	$ 727,185

Repurchase Agreements - Narrati

Repurchase Agreements - Narrative (Detail) - Repurchase Agreements - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Credit Suisse First Boston
Short-term Debt [Line Items]
Amount at risk	$ 451	$ 320
Securities Pledged as Collateral | Nomura Securities Company Limited | Credit Concentration Risk | Stockholders' Equity, Total
Short-term Debt [Line Items]
Collateral posted on repurchase agreements, percentage of equity	12.00%
Securities Pledged as Collateral | Credit Suisse First Boston | Credit Concentration Risk | Stockholders' Equity, Total
Short-term Debt [Line Items]
Collateral posted on repurchase agreements, percentage of equity		10.00%
Weighted average maturity	25 days	104 days

Securitized Debt - Narrative (D

Securitized Debt - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Gains (losses) on extinguishment of debt	$ 12,742	$ (1)	$ (48,014)	$ 0	$ 1,334	$ (45)	$ 0	$ (1,766)	$ (35,274)	$ (477)	$ (5,930)
Securitized Loans | Non-agency MBS
Debt Instrument [Line Items]
Acquired securitized debt collateral outstanding principal balance									166	10,000
Repurchase of securitized debt borrowings, collateralized by Non-Agency RMBS									167	11,000
Gains (losses) on extinguishment of debt									(1)	(355)
Securitized Loans | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure | Non-agency MBS
Debt Instrument [Line Items]
Principal balance of debt	$ 219,000				$ 350,000				$ 219,000	$ 350,000
Weighted average cost of financing	6.20%				5.20%				6.20%	5.20%
Securitized Loans | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure | Loans held for investment
Debt Instrument [Line Items]
Principal balance of debt	$ 9,400,000				$ 7,100,000				$ 9,400,000	$ 7,100,000
Weighted average cost of financing	4.20%				4.00%				4.20%	4.00%
Securitized Loans | Variable Interest Entities, Primary Beneficiary | Loans held for investment
Debt Instrument [Line Items]
Acquired securitized debt collateral outstanding principal balance									$ 1,000,000	$ 609,000
Repurchase of securitized debt borrowings, collateralized by Non-Agency RMBS									1,100,000	609,000
Gains (losses) on extinguishment of debt									$ (35,000)	$ (122)

Securitized Debt - Maturities (

Securitized Debt - Maturities (Detail) - Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure - Securitized Loans - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Non-agency MBS
Debt Instrument [Line Items]
Within One Year	$ 42,217	$ 98,565
One to Three Years	45,916	82,563
Three to Five Years	16,524	23,854
Greater Than Five Years	4,867	31,973
Total	109,524	236,955
Loans held for investment
Debt Instrument [Line Items]
Within One Year	1,819,018	1,151,519
One to Three Years	2,872,572	1,841,808
Three to Five Years	2,140,434	1,423,706
Greater Than Five Years	2,439,872	2,477,123
Total	$ 9,271,896	$ 6,894,156

Securitized Debt - Callable Deb

Securitized Debt - Callable Debt (Detail) - Securitized Loans $ in Thousands	Dec. 31, 2017USD ($)
Debt Instrument, Redemption [Line Items]
2,018	$ 943,573
2,019	397,734
2,020	4,744,768
2,021	2,811,850
2,022	287,157
Total	$ 9,185,082

Consolidated Securitization V76

Consolidated Securitization Vehicles and Other Variable Interest Entities - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Non-agency MBS
Variable Interest Entity [Line Items]
Unconsolidated VIEs, aggregate investment	$ 1,300,000	$ 1,500,000
Non-agency MBS | Minimum
Variable Interest Entity [Line Items]
Unconsolidated VIEs, individual investments (Less than $1 million minimum)	1,000	1,000
Non-agency MBS | Maximum
Variable Interest Entity [Line Items]
Unconsolidated VIEs, individual investments (Less than $1 million minimum)	52,000	51,000
Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Assets	14,987,464	10,761,954
Liabilities	9,631,820	7,302,905
Variable Interest Entities, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Variable interest entity, reporting entity involvement, maximum loss exposure, amount	1,200,000	$ 1,400,000
Subprime | Residential Mortgage
Variable Interest Entity [Line Items]
Mortgage loans	7,400,000
Subsidiaries | Subprime | Residential Mortgage
Variable Interest Entity [Line Items]
Mortgage loans	$ 509,000

Consolidated Securitization V77

Consolidated Securitization Vehicles and Other Variable Interest Entities - Effect on Consolidated Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Non-Agency RMBS, at fair value	$ 2,851,316	$ 3,330,063
Loans held for investment, at fair value	13,678,263	8,753,653
Accrued interest receivable	100,789	79,697
Other Assets	114,391	166,350
Liabilities:
Securitized debt, collateralized by Non-Agency RMBS	205,780	334,124
Securitized debt at fair value, collateralized by loans held for investment	9,388,657	6,941,097
Accrued interest payable	61,888	48,670
Other liabilities	17,191	16,694
Variable Interest Entities, Primary Beneficiary
Assets:
Non-Agency RMBS, at fair value	1,579,793	1,842,080
Loans held for investment, at fair value	13,263,338	8,753,653
Accrued interest receivable	75,489	57,153
Other Assets	68,844	109,068
Liabilities:
Securitized debt, collateralized by Non-Agency RMBS	205,780	334,124
Securitized debt at fair value, collateralized by loans held for investment	9,388,657	6,941,097
Accrued interest payable	33,870	24,942
Other liabilities	3,513	$ 2,742
Consolidated Trusts | Variable Interest Entities, Primary Beneficiary
Assets:
Loans held for investment, at fair value	7,407,677
Other Assets	51,711
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	$ 5,188,457

Consolidated Securitization V78

Consolidated Securitization Vehicles and Other Variable Interest Entities - Effect on Consolidated Results (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Net interest income	$ 157,753	$ 156,455	$ 150,689	$ 141,113	$ 154,086	$ 156,042	$ 137,869	$ 138,213	$ 606,010	$ 586,211	$ 613,372
Total other-than-temporary impairment losses									(5,169)	(9,589)	(8,700)
Portion of loss recognized in other comprehensive income (loss)									(56,687)	(48,398)	(58,744)
Net other-than-temporary credit impairment losses	$ (18,179)	$ (11,468)	$ (13,509)	$ (18,701)	$ (14,780)	$ (11,574)	$ (20,955)	$ (10,678)	(61,856)	(57,987)	(67,444)
Servicing fees									41,690	31,178	25,244
Variable Interest Entities, Primary Beneficiary
Variable Interest Entity [Line Items]
Total other-than-temporary impairment losses									(2,174)	(1,274)	(2,066)
Portion of loss recognized in other comprehensive income (loss)									(51,118)	(37,475)	(55,552)
Net other-than-temporary credit impairment losses									(53,292)	(38,749)	(57,618)
Servicing fees									41,493	31,178	25,244
Non Agency Residential Mortgage Backed Securities And Securitized Loans | Variable Interest Entities, Primary Beneficiary
Variable Interest Entity [Line Items]
Interest income, Assets of consolidated VIEs									914,022	678,623	575,715
Interest expense, Non-recourse liabilities of VIEs									390,858	249,708	191,922
Net interest income									$ 523,164	$ 428,915	$ 383,793

Derivative Instruments - Effect

Derivative Instruments - Effect on Consolidated Financial Condition (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	$ 4,827,100,000	$ 2,640,600,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	48,914,000	9,677,000
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	(320,000)	(2,350,000)
Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	3,816,400,000	1,396,900,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	43,257,000	0
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	0	0
Swaptions
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	391,000,000	624,000,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	2,105,000	7,892,000
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	(320,000)	(2,350,000)
Treasury Futures
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	619,700,000	619,700,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	3,552,000	1,785,000
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	$ 0	$ 0

Derivative Instruments - Effe80

Derivative Instruments - Effect on Consolidated Results (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives									$ 47,976	$ 50,093	$ 67,385
Net gains (losses) on derivatives	$ 31,108	$ 1,363	$ (21,822)	$ (4,462)	$ 115,523	$ 13,360	$ (47,755)	$ (136,537)	6,188	(55,409)	(114,637)
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives									43,697	47,170	64,819
Net realized gains (losses) on derivatives									(31,593)	(88,722)	(146,173)
Mortgage Options
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives									0	0	225
Net realized gains (losses) on derivatives									0	0	443
Treasury Futures
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives									1,768	378	8,634
Net realized gains (losses) on derivatives									(4,061)	(9,170)	(35,523)
Swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives									2,511	2,545	(6,294)
Net realized gains (losses) on derivatives									(6,134)	(7,044)	(353)
Other Derivative Assets
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives									0	0	0
Net realized gains (losses) on derivatives									$ 0	$ (566)	$ (415)

Derivative Instruments - Effe81

Derivative Instruments - Effect on Consolidated Results - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Realized gains (losses) on terminations of interest rate swaps	$ (16,143)	$ (60,616)	$ (98,949)

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Realized losses on terminations of interest rate swaps	$ 16,143,000	$ 60,616,000	$ 98,949,000
Derivative instruments terminated	$ 250,000,000
The weighted average pay rate on the Company's interest rate swaps	1.93%	2.13%
The weighted average receive rate on the Company's interest rate swaps	1.53%	0.90%
The weighted average maturity on the Company's interest rate swaps	5 years	8 years
Fair value of credit risk derivative instruments in a net liability position	$ 37,000,000
Early Terminated Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Derivative instruments terminated		$ 3,300,000,000

Capital Stock - Preferred Stock

Capital Stock - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended								12 Months Ended
	Feb. 28, 2017	Oct. 31, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Preferred Stock, shares authorized (shares)			100,000,000				100,000,000				100,000,000	100,000,000
Preferred Stock, par value (usd per share)			$ 0.01				$ 0.01				$ 0.01	$ 0.01
Issuance of preferred stock cost											$ 314,429	$ 140,065
Dividends on preferred stock			$ 9,400	$ 9,400	$ 9,400	$ 5,283	$ 2,449	$ 0	$ 0	$ 0	$ 33,484	$ 2,449	$ 0
Preferred Class B
Class of Stock [Line Items]
Preferred Stock, shares authorized (shares)	13,000,000
Preferred Stock, dividend rate (percent)	8.00%										8.00%
Sale of stock price (in USD per share)	$ 25
Preferred stock, redemption price per share (in USD per share)	$ 25
Dividends on preferred stock											$ 22,000
Preferred stock dividends declared (in USD per share)											$ 1.6833478462
Preferred Class A
Class of Stock [Line Items]
Preferred Stock, shares authorized (shares)		5,800,000
Preferred Stock, dividend rate (percent)	8.00%	8.00%									8.00%	8.00%
Preferred Stock, par value (usd per share)	$ 0.01	$ 0.01
Sale of stock price (in USD per share)	25	25
Preferred stock, redemption price per share (in USD per share)	25	$ 25
Fixed dividend amount (in USD per share)	$ 2
Dividends on preferred stock											$ 12,000
Preferred stock dividends declared (in USD per share)											$ 2
Preferred stock, issuance cost and discount on shares		$ 140,000
Additional Paid-in Capital
Class of Stock [Line Items]
Issuance of preferred stock cost	$ 314,000										$ 314,299	$ 140,007
London Interbank Offered Rate (LIBOR) | Preferred Class A
Class of Stock [Line Items]
Preferred stock, basis spread on variable rate	5.791%

Capital Stock - Common Stock (D

Capital Stock - Common Stock (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Feb. 20, 2018	Feb. 29, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2015
Class of Stock [Line Items]
Stock repurchase program, authorized amount						$ 250,000,000
Stock repurchase program additional authorized amount		$ 100,000,000
Number of shares repurchased (shares)			0
Stock repurchase program, remaining authorized repurchase amount			$ 100,000,000
Dividends declared per share of common stock (usd per share)			$ 2	$ 2.44	$ 1.92
Common dividends declared			$ 376,579,000	$ 458,735,000	$ 378,804,000
Regular Dividend
Class of Stock [Line Items]
Dividends declared per share of common stock (usd per share)			$ 2	$ 1.94	$ 1.92
Common dividends declared			$ 377,000,000	$ 364,000,000	$ 379,000,000
Special Dividend
Class of Stock [Line Items]
Dividends declared per share of common stock (usd per share)				$ 0.50
Common dividends declared				$ 94,000,000
Subsequent Event
Class of Stock [Line Items]
Stock repurchase program additional authorized amount	$ 100,000,000

Capital Stock - Earnings Per Sh

Capital Stock - Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net income available to common shareholders	$ 98,208	$ 129,832	$ 105,617	$ 157,524	$ 219,454	$ 172,817	$ 74,127	$ 83,098	$ 491,184	$ 549,494	$ 250,349
Effect of dilutive securities:									0	0	0
Dilutive net income available to common shareholders									$ 491,184	$ 549,494	$ 250,349
Denominator:
Weighted average basic shares (shares)									187,780,355	187,728,634	199,563,196
Effect of dilutive securities (shares)									506,965	296,204	86,981
Weighted average dilutive shares (shares)									188,287,320	188,024,838	199,650,177
Net income per average share attributable to common stockholders - Basic (usd per share)	$ 0.52	$ 0.69	$ 0.56	$ 0.84	$ 1.17	$ 0.92	$ 0.39	$ 0.44	$ 2.62	$ 2.93	$ 1.25
Net income per average share attributable to common stockholders - Diluted (usd per share)									$ 2.61	$ 2.92	$ 1.25

Accumulated Other Comprehensi86

Accumulated Other Comprehensive Income - Components of AOCI (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
AOCI [Roll Forward]
Beginning Balance	$ 3,123,533	$ 2,946,188
OCI before reclassifications	24,218	(88,527)
Amounts reclassified from AOCI	54,578	32,842
Net current period OCI	78,796	(55,685)
Ending Balance	3,634,977	3,123,533
Unrealized gains (losses) on available-for-sale securities, net
AOCI [Roll Forward]
Beginning Balance	718,106	773,791
OCI before reclassifications	24,218	(88,527)
Amounts reclassified from AOCI	54,578	32,842
Net current period OCI	78,796	(55,685)
Ending Balance	796,902	718,106
Total Accumulated OCI Balance
AOCI [Roll Forward]
Beginning Balance	718,106	773,791
Ending Balance	$ 796,902	$ 718,106

Accumulated Other Comprehensi87

Accumulated Other Comprehensive Income - Reclassifications from AOCI (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on sales of investments	$ (586)	$ 1	$ 4,541	$ 5,167	$ 11,121	$ 3,079	$ 6,631	$ (2,674)	$ 9,123	$ 18,155	$ 77,074
Net other-than-temporary credit impairment losses	(18,179)	(11,468)	(13,509)	(18,701)	(14,780)	(11,574)	(20,955)	(10,678)	(61,856)	(57,987)	(67,444)
Income before income taxes									524,776	552,026	250,350
Income taxes									(108)	(83)	(1)
Net income (loss)	$ 107,608	$ 139,232	$ 115,017	$ 162,807	$ 221,903	$ 172,817	$ 74,127	$ 83,098	524,668	551,943	$ 250,349
Amounts Reclassified from Accumulated OCI | Unrealized gains (losses) on available-for-sale securities, net
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on sales of investments									7,278	25,145
Net other-than-temporary credit impairment losses									(61,856)	(57,987)
Income before income taxes									(54,578)	(32,842)
Income taxes									0	0
Net income (loss)									$ (54,578)	$ (32,842)

Equity Compensation, Employme88

Equity Compensation, Employment Agreements and other Benefit Plans - Narrative (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)installmentshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeitures (shares) | shares	0	0
Granted shares (shares) | shares	348,244	539,847
Common dividends declared	$ 4,000,000	$ 2,000,000	$ 1,000,000
401(k) Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum annual contributions per employee, amount	18,000
Maximum annual contribution per employee, additional contribution per employee over certain age	6,000
Expense related to qualified plan	$ 376,000	$ 335,000	$ 82,000
Maximum | 401(k) Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees' gross pay	6.00%
Stock Award Deferral Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of installments | installment	5
Restricted Stock | 2007 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (shares) | shares	6,000,000
Restricted Stock | 2007 Equity Incentive Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock | 2007 Equity Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	10 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Forfeitures (shares) | shares	204,000	360,000
Grant date fair value	$ 4,000,000	$ 5,000,000
Restricted Stock Units (RSUs) | One year from grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Restricted Stock Units (RSUs) | Two years from grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Restricted Stock Units (RSUs) | Three years from grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Grant date fair value	$ 3,000,000	$ 3,000,000
Granted shares (shares) | shares	144,000	180,000
Performance period	3 years
Performance Share Units | One year from grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Performance Share Units | Two years from grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Performance Share Units | Three years from grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Performance Share Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	0.00%
Performance Share Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	150.00%

Equity Compensation, Employme89

Equity Compensation, Employment Agreements and other Benefit Plans - Schedule of Unvested Shares Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Unvested shares outstanding - beginning of period (in shares)	577,547	71,000
Granted shares (shares)	348,244	539,847
Vested (in shares)	(155,976)	(33,300)
Forfeitures (shares)	0	0
Unvested shares outstanding - end of period (in shares)	769,815	577,547
Weighted Average Grant Date Fair Value
Unvested shares outstanding - beginning of period (in USD per share)	$ 14.53	$ 28.39
Granted (in USD per share)	18.68	13.49
Vested (in USD per share)	30.74	27.23
Forfeited (in USD per share)	0	0
Unvested shares outstanding - end of period (in USD per share)	$ 25.58	$ 14.53

Income Taxes Income Taxes (Deta

Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax expense	$ 108	$ 83	$ 1
Deferred tax assets recorded	4,000	5,000
Deferred tax assets related to cumulative net operating losses	1,000	2,000
Deferred tax assets related to other losses	3,000	3,000
Valuation allowance	$ 4,000	$ 5,000

Credit Risk and Interest Rate91

Credit Risk and Interest Rate Risk - Offsetting Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Repurchase Agreements
Gross Amounts of Recognized Assets (Liabilities)	$ (7,250,452)	$ (5,600,903)
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	(7,250,452)	(5,600,903)
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	8,788,680	7,033,866
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	1,156	2,545
Net Amount	1,539,384	1,435,508
Derivative Asset
Net Amounts Offset in the Consolidated Statements of Financial Position	48,914	9,677
Derivative Liability
Net Amounts Offset in the Consolidated Statements of Financial Position	(320)	(2,350)
Total Liabilities
Gross Amounts of Recognized Assets (Liabilities)	(7,201,858)	(5,594,016)
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	440
Net Amounts Offset in the Consolidated Statements of Financial Position	(7,201,858)	(5,593,576)
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	8,788,680	7,044,207
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	13,102	45,492
Net Amount	1,599,924	1,496,123
Interest Rate Swaps
Derivative Asset
Gross Amounts of Recognized Assets (Liabilities)	44,874	14,435
Gross Amounts Offset in the Consolidated Statements of Financial Position	(1,617)	(14,435)
Net Amounts Offset in the Consolidated Statements of Financial Position	43,257	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	11,570	0
Net Amount	54,827	0
Derivative Liability
Gross Amounts of Recognized Assets (Liabilities)	(1,617)	(14,875)
Gross Amounts Offset in the Consolidated Statements of Financial Position	1,617	14,875
Net Amounts Offset in the Consolidated Statements of Financial Position	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	0	39,627
Net Amount	0	39,627
Treasury Futures
Derivative Asset
Gross Amounts of Recognized Assets (Liabilities)	3,552	1,785
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	3,552	1,785
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	376	3,320
Net Amount	3,928	5,105
Derivative Liability
Gross Amounts of Recognized Assets (Liabilities)	0	0
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	0	0
Net Amount	0	0
Swaptions
Derivative Asset
Gross Amounts of Recognized Assets (Liabilities)	2,105	7,892
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	2,105	7,892
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	0	0
Net Amount	2,105	7,892
Derivative Liability
Gross Amounts of Recognized Assets (Liabilities)	(320)	(2,350)
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	(320)	(2,350)
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	0	10,341
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	0	0
Net Amount	$ (320)	$ 7,991

Summarized Quarterly Results 92

Summarized Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Net interest income:
Interest income	$ 301,957	$ 296,813	$ 288,644	$ 251,344	$ 260,823	$ 250,953	$ 221,096	$ 201,194	$ 1,138,758	[1]	$ 934,068	[1]	$ 872,737	[1]
Interest expense	144,204	140,358	137,955	110,231	106,737	94,911	83,227	62,981	532,748	[2]	347,857	[2]	259,365	[2]
Net interest income	157,753	156,455	150,689	141,113	154,086	156,042	137,869	138,213	606,010		586,211		613,372
Other-than-temporary impairments:
Total other-than-temporary impairment losses	(923)	(784)	(749)	(2,713)	(1,034)	(993)	(3,129)	(4,423)
Portion of loss recognized in other comprehensive income (loss)	(17,256)	(10,684)	(12,760)	(15,988)	(13,746)	(10,581)	(17,816)	(6,255)
Net other-than-temporary credit impairment losses	(18,179)	(11,468)	(13,509)	(18,701)	(14,780)	(11,574)	(20,955)	(10,678)	(61,856)		(57,987)		(67,444)
Net gains (losses) on derivatives	31,108	1,363	(21,822)	(4,462)	115,523	13,360	(47,755)	(136,537)	6,188		(55,409)		(114,637)
Net unrealized gains (losses) on financial instruments at fair value	(47,637)	19,042	67,762	72,243	(20,664)	32,999	30,347	16,871	111,410		59,552		(158,433)
Net realized gains (losses) on sales of investments	(586)	1	4,541	5,167	11,121	3,079	6,631	(2,674)	9,123		18,155		77,074
Gain (loss) on Extinguishment of Debt	12,742	(1)	(48,014)	0	1,334	(45)	0	(1,766)	(35,274)		(477)		(5,930)
Other income					0	0	0	95,000	0		95,000		0
Total other expenses	27,657	26,142	24,491	32,537	24,698	21,031	31,987	15,302	110,825		93,019		93,396
Net income (loss)	107,608	139,232	115,017	162,807	221,903	172,817	74,127	83,098	524,668		551,943		250,349
Dividend on preferred stock	9,400	9,400	9,400	5,283	2,449	0	0	0	33,484		2,449		0
Net income (loss) available to common shareholders	$ 98,208	$ 129,832	$ 105,617	$ 157,524	$ 219,454	$ 172,817	$ 74,127	$ 83,098	$ 491,184		$ 549,494		$ 250,349
Net income per common share-basic (usd per share)	$ 0.52	$ 0.69	$ 0.56	$ 0.84	$ 1.17	$ 0.92	$ 0.39	$ 0.44	$ 2.62		$ 2.93		$ 1.25
[1]	Includes interest income of consolidated VIEs of $914,022, $678,623 and $575,715 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 8 to consolidated financial statements for further discussion.
[2]	Includes interest expense of consolidated VIEs of $390,858, $249,708 and $191,922 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 8 to consolidated financial statements for further discussion.