Chimera Investment (CIM) 10-Q 2 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 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-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		187,781,029

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Assets:
Cash and cash equivalents		$ 38,055	$ 177,714
Non-Agency RMBS, at fair value		2,950,348	3,330,063
Agency MBS, at fair value		4,354,872	4,167,754
Loans held for investment, at fair value		13,538,052	8,753,653
Receivable for investment sold		11,235	0
Accrued interest receivable		99,421	79,697
Other assets		172,876	166,350
Derivatives, at fair value, net		22,525	9,677
Total assets	[1]	21,187,384	16,684,908
Liabilities:
Repurchase agreements ($8.2 billion and $7.0 billion, pledged as collateral, respectively)		6,709,821	5,600,903
Securitized debt, collateralized by Non-Agency RMBS ($1.6 billion and $1.8 billion pledged as collateral, respectively)		233,113	334,124
Securitized debt at fair value, collateralized by loans held for investment ($13.0 billion and $8.8 billion pledged as collateral, respectively)		9,683,062	6,941,097
Payable for investments purchased		733,142	520,532
Accrued interest payable		64,280	48,670
Dividends payable		95,000	97,005
Accounts payable and other liabilities		21,331	16,694
Derivatives, at fair value		1,204	2,350
Total liabilities	[1]	17,540,953	13,561,375
Commitments and Contingencies (See Note 15)
Stockholders' Equity:
Common stock: par value $0.01 per share; 300,000,000 shares authorized, 187,781,000 and 187,739,634 shares issued and outstanding, respectively		1,878	1,877
Additional paid-in-capital		3,825,832	3,508,779
Accumulated other comprehensive income		813,118	718,106
Cumulative earnings		2,860,244	2,443,184
Cumulative distributions to stockholders		(3,854,829)	(3,548,471)
Total stockholders' equity		3,646,431	3,123,533
Total liabilities and stockholders' equity		21,187,384	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 September 30, 2017 and December 31, 2016, total assets of consolidated VIEs were $14,846,980 and $10,761,954, respectively, and total liabilities of consolidated VIEs were $9,954,437 and $7,302,905, respectively. See Note 8 for further discussion.

CONSOLIDATED STATEMENTS OF FIN3

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 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)	187,781,000	187,739,634
Common stock, shares outstanding (shares)	187,781,000	187,739,634
Repurchase Agreements | Residential Mortgage-Backed Securities
Securities pledged as collateral	$ 8,150,309,000	$ 7,033,866,000
Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Assets	14,846,980,000	10,761,954,000
Liabilities	9,954,437,000	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	$ 13,000,000,000	$ 8,800,000,000
Preferred Class A
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 Stock, dividend rate (percent)	8.00%	8.00%
Preferred Class B
Preferred Stock, shares issued (shares)	13,000,000
Preferred Stock, shares outstanding (shares)	0
Preferred Stock, liquidation preference	$ 325,000
Preferred Stock, dividend rate (percent)	8.00%

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net interest income:
Interest income	[1]	$ 296,813	$ 250,953	$ 836,801	$ 673,246
Interest expense	[2]	140,358	94,911	388,544	241,120
Net interest income		156,455	156,042	448,257	432,126
Other-than-temporary impairments:
Total other-than-temporary impairment losses		(784)	(993)	(4,245)	(8,555)
Portion of loss recognized in other comprehensive income		(10,684)	(10,581)	(39,431)	(34,652)
Net other-than-temporary credit impairment losses		(11,468)	(11,574)	(43,676)	(43,207)
Other investment gains (losses):
Net unrealized gains (losses) on derivatives		9,204	27,628	19,902	(51,382)
Realized gains (losses) on terminations of interest rate swaps		0	0	(16,143)	(60,616)
Net realized gains (losses) on derivatives		(7,841)	(14,268)	(28,680)	(58,934)
Net gains (losses) on derivatives		1,363	13,360	(24,921)	(170,932)
Net unrealized gains (losses) on financial instruments at fair value		19,042	32,999	159,047	80,217
Net realized gains (losses) on sales of investments		1	3,079	9,709	7,035
Gains (losses) on extinguishment of debt		(1)	(45)	(48,016)	(1,811)
Total other gains (losses)		20,405	49,393	95,819	(85,491)
Other income:
Other income		0	0	0	95,000
Total other income		0	0	0	95,000
Other expenses:
Compensation and benefits		7,533	6,911	22,759	19,087
General and administrative expenses		4,537	4,332	13,162	13,073
Servicing fees		10,715	9,788	31,193	23,139
Deal expenses		3,357	0	16,054	13,022
Total other expenses		26,142	21,031	83,168	68,321
Income (loss) before income taxes		139,250	172,830	417,232	330,107
Income taxes		18	13	172	65
Net income (loss)		139,232	172,817	417,060	330,042
Dividend on preferred stock		9,400	0	24,083	0
Net income (loss) available to common shareholders		$ 129,832	$ 172,817	$ 392,977	$ 330,042
Net income (loss) per share available to common shareholders:
Basic (usd per share)		$ 0.69	$ 0.92	$ 2.09	$ 1.76
Diluted (usd per share)		$ 0.69	$ 0.92	$ 2.09	$ 1.76
Weighted average number of common shares outstanding:
Basic (shares)		187,779,794	187,729,765	187,773,715	187,727,667
Diluted (shares)		188,192,111	187,919,792	188,176,757	187,917,694
Dividends declared per share of common stock (usd per share)		$ 0.5	$ 0.48	$ 1.5	$ 1.94
[1]	Includes interest income of consolidated VIEs of $241,195 and $195,488 for the quarters ended September 30, 2017 and 2016, respectively and interest income of consolidated VIEs of $668,621 and $488,353 for the nine months ended September 30, 2017 and 2016 respectively. See Note 8 to consolidated financial statements for further discussion.
[2]	Includes interest expense of consolidated VIEs of $101,856 and $70,715 for the quarters ended September 30, 2017 and 2016, respectively and interest expense of consolidated VIEs of $290,264 and $168,738 for the nine months ended September 30, 2017 and 2016 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	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest income, assets of consolidated VIEs	$ 241,195	$ 195,488	$ 668,621	$ 488,353
Interest expense, non-recourse liabilities of VIEs	$ 101,856	$ 70,715	$ 290,264	$ 168,738

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Comprehensive income (loss):
Net income (loss)	$ 139,232	$ 172,817	$ 417,060	$ 330,042
Other comprehensive income:
Unrealized gains (losses) on available-for-sale securities, net	21,370	(18,364)	59,114	94,059
Reclassification adjustment for net losses included in net income for other-than-temporary credit impairment losses	11,468	11,574	43,676	43,207
Reclassification adjustment for net realized losses (gains) included in net income	(1)	(2,680)	(7,778)	(13,354)
Other comprehensive income (loss)	32,837	(9,470)	95,012	123,912
Comprehensive income (loss) before preferred stock dividends	172,069	163,347	512,072	453,954
Dividends on preferred stock	9,400	0	24,083	0
Comprehensive income (loss) available to common stock shareholders	$ 162,669	$ 163,347	$ 487,989	$ 453,954

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, 2015	$ 2,946,188	$ 1,877	$ 3,366,568	$ 773,791	$ 1,891,239	$ (3,087,287)		$ 0		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	330,042				330,042
Other comprehensive income (loss)	123,912			123,912
Stock based compensation	1,375		1,375
Common dividends declared	(364,717)					(364,717)
Preferred dividends declared	0
Ending Balance at Sep. 30, 2016	3,036,800	1,877	3,367,943	897,703	2,221,281	(3,452,004)		0		0
Beginning 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)	417,060				417,060
Other comprehensive income (loss)	95,012			95,012
Stock based compensation	2,755	1	2,754
Common dividends declared	(282,275)					(282,275)
Preferred dividends declared	(24,083)					(24,083)	$ (9,000)		$ (15,000)
Issuance of preferred stock	314,429		314,299							130
Ending Balance at Sep. 30, 2017	$ 3,646,431	$ 1,878	$ 3,825,832	$ 813,118	$ 2,860,244	$ (3,854,829)		$ 58		$ 130

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Cash Flows From Operating Activities:
Net income	$ 417,060	$ 330,042
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
(Accretion) amortization of investment discounts/premiums, net	(17,269)	4,084
Accretion (amortization) of deferred financing costs and securitized debt discounts/premiums, net	6,649	(5,769)
Amortization of swaption premium	5,468	5,130
Net unrealized losses (gains) on derivatives	(19,902)	51,382
Margin (paid) received on derivatives	(3,948)	(41,283)
Net unrealized losses (gains) on financial instruments at fair value	(159,047)	(80,217)
Net realized losses (gains) on sales of investments	(9,709)	(7,035)
Net other-than-temporary credit impairment losses	43,676	43,207
(Gain) loss on extinguishment of debt	48,016	1,811
Equity-based compensation expense	2,755	1,375
Changes in operating assets:
Decrease (increase) in accrued interest receivable, net	(19,738)	(18,081)
Decrease (increase) in other assets	(5,076)	(36,969)
Changes in operating liabilities:
Increase (decrease) in accounts payable and other liabilities	4,635	3,905
Increase (decrease) in accrued interest payable, net	15,631	12,311
Net cash provided by (used in) operating activities	309,201	263,893
Cash Flows From Investing Activities:
Net cash provided by (used in) investing activities	(4,055,012)	(1,494,982)
Cash Flows From Financing Activities:
Proceeds from repurchase agreements	29,079,905	27,792,856
Payments on repurchase agreements	(27,970,987)	(29,414,676)
Net proceeds from preferred stock offerings	314,429	0
Proceeds from securitized debt borrowings, collateralized by loans held for investment	4,159,073	4,180,227
Payments on securitized debt borrowings, collateralized by loans held for investment	(1,564,489)	(773,875)
Payments on securitized debt borrowings, collateralized by Non-Agency RMBS	(103,415)	(146,729)
Common dividends paid	(281,832)	(364,168)
Preferred dividends paid	(26,532)	0
Net cash provided by (used in) financing activities	3,606,152	1,273,635
Net increase (decrease) in cash and cash equivalents	(139,659)	42,546
Cash and cash equivalents at beginning of period	177,714	114,062	$ 114,062
Cash and cash equivalents at end of period	38,055	156,608	177,714
Supplemental disclosure of cash flow information:
Interest received	799,808	659,249
Interest paid	366,284	234,577
Non-cash investing activities:
Payable for investments purchased	733,142	578,499
Receivable for investment sold	11,235		0
Receivable for investments sold			$ 0
Net change in unrealized gain (loss) on available-for sale securities	95,012	123,912
Non-cash financing activities:
Common dividends declared, not yet paid	95,000	90,645
Agency MBS portfolio
Cash Flows From Investing Activities:
Purchases	(1,000,336)	(810,630)
Sales	693,207	2,555,228
Principal payments	332,140	471,657
Non-agency MBS
Cash Flows From Investing Activities:
Purchases	(7,978)	(160,805)
Sales	5,045	95,399
Principal payments	459,854	402,971
Loans held for investment:
Cash Flows From Investing Activities:
Purchases	(5,835,799)	(4,745,083)
Principal payments	$ 1,298,855	$ 696,281

Organization

Organization	9 Months Ended
	Sep. 30, 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	9 Months Ended
	Sep. 30, 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 significant 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 purpose 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 generally only be satisfied from each securitization vehicle’s respective asset pool. The assets of securitization entities are comprised of senior classes 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) 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. (d) Significant Accounting Policies There have been no significant changes to the Company's accounting policies included in Note 2 to the consolidated financial statements of the Company’s Form 10-K for the year ended December 31, 2016 , other than the significant accounting policies disclosed below. Income Taxes 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 September 30, 2017 or December 31, 2016 . Fair Value Disclosure 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 this date 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. 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. (e) 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. Early adoption is allowed. The amendments in this update should be applied prospectively on or after the effective date. No disclosures are required at transition. The Company is not planning to early adopt and is currently evaluating what impact this update will have on the 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. Early adoption is allowed. The amendments in this update should be applied using a retrospective transition method to each period presented. The Company is not planning to early adopt and is currently evaluating what impact this update will have on the 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 Company did not elect to early adopt the provisions of this update. The Company is currently evaluating what impact this update will have on the consolidated financial statements. 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. Early adoption for certain provisions of the update is allowed. Any adjustment as a result of the adoption of this standard will be recorded as a cumulative-effect adjustment to beginning retained earnings as of the first period in which the guidance is adopted. The Company did not elect to early adopt the provisions of this update and is currently evaluating what impact this update will have on the consolidated financial statements.

Mortgage-Backed Securities

Mortgage-Backed Securities	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 . September 30, 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 $ 2,821,535 $ 224 $ (1,282,801 ) $ 1,538,958 $ 2,304,611 $ 765,653 $ — $ 765,653 Senior, interest-only 4,948,265 267,964 — 267,964 212,662 13,620 (68,922 ) (55,302 ) Subordinated 531,526 10,764 (188,169 ) 354,121 421,487 67,430 (64 ) 67,366 Subordinated, interest-only 256,286 12,968 — 12,968 11,588 860 (2,240 ) (1,380 ) Agency MBS Residential 2,316,838 128,388 — 2,445,226 2,428,112 7,606 (24,720 ) (17,114 ) Commercial 1,774,802 44,913 (4,732 ) 1,814,983 1,811,950 13,467 (16,500 ) (3,033 ) Interest-only 3,176,110 121,353 — 121,353 114,810 1,226 (7,769 ) (6,543 ) Total $ 15,825,362 $ 586,574 $ (1,475,702 ) $ 6,555,573 $ 7,305,220 $ 869,862 $ (120,215 ) $ 749,647 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 Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) (dollars in thousands) Balance at beginning of period $ 1,383,188 $ 1,714,592 $ 1,550,110 $ 1,742,744 Purchases 8,196 18,316 18,380 60,915 Yield income earned (66,042 ) (69,850 ) (202,618 ) (141,256 ) Reclassification (to) from non-accretable difference 53,884 (29,490 ) 15,777 (2,031 ) Sales and deconsolidation (17,755 ) (12,907 ) (20,178 ) (39,711 ) Balance at end of period $ 1,361,471 $ 1,620,661 $ 1,361,471 $ 1,620,661 The table below presents the outstanding principal balance and related amortized cost at September 30, 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 Quarter Ended For the Year Ended September 30, 2017 December 31, 2016 (dollars in thousands) Outstanding principal balance: Beginning of period $ 2,910,151 $ 3,550,698 End of period $ 2,772,746 $ 3,138,265 Amortized cost: Beginning of period $ 1,546,656 $ 1,958,726 End of period $ 1,449,531 $ 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 September 30, 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) of 2016, Form 10-K. September 30, 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 $ — $ — — $ — $ — — $ — $ — — Senior, interest-only 82,130 (15,487 ) 54 73,232 (53,435 ) 93 155,362 (68,922 ) 147 Subordinated 5,353 (64 ) 7 — — 1 5,353 (64 ) 8 Subordinated, interest-only 574 (331 ) 2 4,220 (1,909 ) 2 4,794 (2,240 ) 4 Agency MBS Residential 1,932,140 (17,187 ) 95 234,050 (7,533 ) 11 2,166,190 (24,720 ) 106 Commercial 876,181 (15,291 ) 241 30,311 (1,209 ) 1 906,492 (16,500 ) 242 Interest-only 29,250 (1,003 ) 12 58,031 (6,766 ) 21 87,281 (7,769 ) 33 Total $ 2,925,628 $ (49,363 ) 411 $ 399,844 $ (70,852 ) 129 $ 3,325,472 $ (120,215 ) 540 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 ) 1002 At September 30, 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 September 30, 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 $37 million and $100 million as of September 30, 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 September 30, 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 $45 thousand and $485 thousand at September 30, 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 quarters and nine months ended September 30, 2017 and 2016 are presented below. For the Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) Total other-than-temporary impairment losses $ (784 ) $ (993 ) $ (4,245 ) $ (8,555 ) Portion of loss recognized in other comprehensive income (loss) (10,684 ) (10,581 ) (39,431 ) (34,652 ) Net other-than-temporary credit impairment losses $ (11,468 ) $ (11,574 ) $ (43,676 ) $ (43,207 ) 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 Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) Cumulative credit loss beginning balance $ 571,639 $ 546,187 $ 556,485 $ 529,112 Additions: Other-than-temporary impairments not previously recognized — 6,184 12,399 17,137 Reductions for securities sold or deconsolidated during the period (4,965 ) (2,630 ) (12,405 ) (6,890 ) Increases related to other-than-temporary impairments on securities with previously recognized other-than-temporary impairments 11,468 5,390 29,302 26,069 Reductions for increases in cash flows expected to be collected over the remaining life of the securities (3,241 ) (1,494 ) (10,880 ) (11,791 ) Cumulative credit impairment loss ending balance $ 574,901 $ 553,637 $ 574,901 $ 553,637 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 Nine Months Ended September 30, 2017 September 30, 2016 Loss Severity Weighted Average 67% 59% Range 28% - 89% 25% - 85% 60+ days delinquent Weighted Average 21% 21% Range 11% - 27% 0% - 40% Credit Enhancement (1) Weighted Average 15% 29% Range 0% - 50% 0% - 100% 3 Month CPR Weighted Average 13% 5% Range 2% - 24% 0% - 19% 12 Month CPR Weighted Average 13% 4% Range 4% - 19% 0% - 21% (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 September 30, 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 September 30, 2017 , IO MBS had a net unrealized loss of $63 million and had an amortized cost of $402 million . At December 31, 2016 , IO MBS had a net unrealized loss of $48 million and had an amortized cost of $458 million . The fair value of IOs at September 30, 2017 and December 31, 2016 was $339 million and $410 million , respectively. All changes in fair value of IOs are reflected in Net Income in the Consolidated Statements of Operations. September 30, 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 $ 765,653 $ — $ 765,653 $ — $ — $ — Senior, interest-only — 13,620 13,620 — (68,922 ) (68,922 ) Subordinated 63,348 4,082 67,430 (45 ) (19 ) (64 ) Subordinated, interest-only — 860 860 — (2,240 ) (2,240 ) Agency MBS Residential 7,606 — 7,606 (22,263 ) (2,457 ) (24,720 ) Commercial 13,339 128 13,467 (14,520 ) (1,980 ) (16,500 ) Interest-only — 1,226 1,226 — (7,769 ) (7,769 ) Total $ 849,946 $ 19,916 $ 869,862 $ (36,828 ) $ (83,387 ) $ (120,215 ) 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 September 30, 2017 and December 31, 2016 . September 30, 2017 Principal or Notional Value at Period-End (dollars in thousands) Weighted Average Amortized Cost Basis Weighted Average Fair Value Weighted Average Coupon Weighted Average Yield at Period-End (1) Non-Agency RMBS Senior $ 2,821,535 $ 54.54 $ 81.68 4.4 % 16.7 % Senior, interest-only 4,948,265 5.42 4.30 1.4 % 7.8 % Subordinated 531,526 66.62 79.30 4.1 % 9.2 % Subordinated, interest-only 256,286 5.06 4.52 1.0 % 8.4 % Agency MBS Residential pass-through 2,316,838 105.54 104.80 3.8 % 2.9 % Commercial pass-through 1,774,802 102.26 102.09 3.6 % 3.2 % Interest-only 3,176,110 3.82 3.61 0.7 % 3.5 % (1) Bond Equivalent Yield at period end. December 31, 2016 Principal or Notional Value at Period-End (dollars in thousands) Weighted Average Amortized Cost Basis Weighted Average Fair Value Weighted Average Coupon 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 September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 AAA 0.3 % 0.3 % AA 0.3 % 0.3 % A 0.6 % 0.7 % BBB 0.4 % 0.7 % BB 2.9 % 3.0 % B 2.1 % 3.9 % Below B 62.4 % 67.2 % Not Rated 31.0 % 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 September 30, 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. September 30, 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 $ 5,611 $ 757,644 $ 881,904 $ 659,452 $ 2,304,611 Senior interest-only 113 55,264 72,087 85,198 212,662 Subordinated — 83,242 183,777 154,468 421,487 Subordinated interest-only — 133 11,455 — 11,588 Agency MBS Residential — 32,666 2,395,446 — 2,428,112 Commercial — 46,263 16,817 1,748,870 1,811,950 Interest-only — 82,985 27,122 4,703 114,810 Total fair value $ 5,724 $ 1,058,197 $ 3,588,608 $ 2,652,691 $ 7,305,220 Amortized cost Non-Agency RMBS Senior $ 5,457 $ 549,443 $ 563,522 $ 420,536 $ 1,538,958 Senior interest-only 1,301 78,615 91,461 96,587 267,964 Subordinated — 67,164 152,048 134,909 354,121 Subordinated interest-only — 152 12,816 — 12,968 Agency MBS Residential — 33,035 2,412,191 — 2,445,226 Commercial — 47,639 17,216 1,750,128 1,814,983 Interest-only — 87,733 29,200 4,420 121,353 Total amortized cost $ 6,758 $ 863,781 $ 3,278,454 $ 2,406,580 $ 6,555,573 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 September 30, 2017 and December 31, 2016 , 69% and 68% of the Non-Agency RMBS collateral was classified as Alt-A, respectively. At September 30, 2017 and December 31, 2016 , 11% 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 September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 Weighted average maturity (years) 20.9 21.6 Weighted average amortized loan to value (1) 65.1 % 66.5 % Weighted average FICO (2) 674 675 Weighted average loan balance (in thousands) $ 320 $ 319 Weighted average percentage owner occupied 83.9 % 83.2 % Weighted average percentage single family residence 65.7 % 65.8 % Weighted average current credit enhancement 2.2 % 2.3 % Weighted average geographic concentration of top four states CA 32.0 % CA 32.1 % NY 8.4 % FL 8.1 % FL 8.2 % 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 September 30, 2017 and December 31, 2016 . Origination Year September 30, 2017 December 31, 2016 2003 and prior 3.6 % 3.6 % 2004 4.8 % 4.2 % 2005 19.7 % 20.2 % 2006 39.8 % 38.0 % 2007 29.6 % 31.3 % 2008 1.7 % 1.8 % 2009 and later 0.8 % 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 quarters and nine months ended September 30, 2017 and 2016 are as follows: For the Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) Proceeds from sales $ 598,752 $ 58,036 $ 772,496 $ 2,697,239 Gross realized gains 6,902 3,622 17,468 16,798 Gross realized losses (6,901 ) (543 ) (7,759 ) (9,763 ) Net realized gain (loss) $ 1 $ 3,079 $ 9,709 $ 7,035 Included in the gross realized gains for the quarter and nine months ended September 30, 2017 in the table above are exchanges of securities with a fair value of $36 million and $63 million , respectively. 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 $4 million and $9 million , respectively, reflected in earnings for the quarter and nine months ended September 30, 2017 . For the quarter and nine months ended September 30, 2016, the fair value of these exchanges of securities was $30 million and $47 million and resulted in a realized gain of $2 million and $1 million , respectively.

Loans Held for Investment

Loans Held for Investment	9 Months Ended
	Sep. 30, 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 September 30, 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 $13.1 billion and $8.6 billion as of September 30, 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 September 30, 2017 and December 31, 2016 : For the Nine Months Ended For the Year Ended September 30, 2017 December 31, 2016 (dollars in thousands) Balance, beginning of period $ 8,753,653 $ 4,768,416 Purchases 5,835,799 4,897,370 Principal paydowns (1,298,856 ) (1,022,414 ) Sales and settlements 2,942 5,007 Net periodic accretion (amortization) (27,310 ) (41,363 ) Change in fair value 271,824 146,637 Balance, end of period $ 13,538,052 $ 8,753,653 The primary cause of the change in fair value is due to changes in credit risk of the portfolio. Residential mortgage loans The loan portfolio for all residential mortgages were originated during the following years: Origination Year September 30, 2017 December 31, 2016 2002 and prior 7.7 % 8.9 % 2003 6.9 % 5.2 % 2004 15.3 % 11.9 % 2005 20.9 % 20.5 % 2006 21.8 % 22.0 % 2007 18.8 % 20.9 % 2008 5.9 % 6.5 % 2009 0.6 % 0.6 % 2010 and later 2.1 % 3.5 % Total 100.0 % 100.0 % The following table presents a summary of key characteristics of the residential loan portfolio at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Number of loans 147,340 95,155 Weighted average maturity (years) 18.8 19.8 Weighted average loan to value (1) 87.9 % 86.9 % Weighted average FICO (1) 629 627 Weighted average loan balance (in thousands) $ 90 $ 93 Weighted average percentage owner occupied 94.0 % 96.6 % Weighted average percentage single family residence 85.0 % 85.0 % Weighted average geographic concentration of top five states CA 9.2 % CA 10.0 % FL 7.1 % FL 6.7 % OH 6.2 % OH 6.5 % PA 5.6 % VA 5.9 % VA 5.4 % NC 5.1 % (1) As provided by the Trustee. The following table summarizes the outstanding principal balance of the residential loan portfolio which are 30 days delinquent and greater as reported by the servicer at September 30, 2017 and December 31, 2016 . 30 Days Delinquent 60 Days Delinquent 90+ Days Delinquent Bankruptcy Foreclosure REO Total Unpaid Principal/Notional (dollars in thousands) September 30, 2017 $462,865 $157,872 $294,458 $230,435 $172,129 $30,306 $1,348,065 $13,327,252 % of Unpaid Principal/Notional 3.5% 1.2% 2.2% 1.7% 1.3% 0.2% 10.1% December 31, 2016 $363,899 $140,495 $190,991 $207,364 $203,265 $40,709 $1,146,723 $8,868,783 % of Unpaid Principal/Notional 4.1% 1.6% 2.2% 2.3% 2.3% 0.5% 12.9% The fair value of residential mortgage loans 90 days or more past due was $591 million and $449 million as of September 30, 2017 and December 31, 2016 , respectively. 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 September 30, 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.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 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, while 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 September 30, 2017 , four investment holdings with an internally developed fair value of $21 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 $17 million lower than the third party prices provided of $38 million . After review and discussion, the Company affirmed and valued the investments at the lower internally developed prices. No other differences were noted at September 30, 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. 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 $224 million and $266 million as of September 30, 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 $115 million and $145 million as of September 30, 2017 and December 31, 2016 . Interest income on all IO MBS securities was $7 million and $10 million for the quarters ended September 30, 2017 and 2016 , respectively. Interest income reported on all IO MBS securities was $24 million and $32 million for the nine months ended September 30, 2017 and 2016 , respectively. 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 this date will continue to be carried at fair value with changes in fair value reported in other comprehensive income (OCI) as available-for-sale investments, consistent with the Company’s current accounting practices. 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: 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 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 $15 million and $19 million as of September 30, 2017 and December 31, 2016 , respectively. 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 September 30, 2017 and 2016 , respectively: September 30, 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 14,761 2,678 1,791 Senior, interest-only 4,948,265 212,662 1,784 (16,446 ) Subordinated, interest-only 256,286 11,588 1,048 475 Agency MBS Residential Pass-through $ 586,030 $ 614,758 $ (2,457 ) $ (2,457 ) Commercial Pass-through 407,943 410,013 (1,852 ) (1,852 ) Interest-only 3,176,110 114,810 (779 ) 831 Loans held for investment, at fair value 13,327,252 13,538,052 57,114 271,824 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 9,622,994 9,683,062 (38,494 ) (95,120 ) September 30, 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 20,671 8,257 7,551 Senior, interest-only 5,733,457 291,526 2,214 22,332 Subordinated, interest-only 269,868 13,498 1,289 3,288 Agency MBS Residential Pass-through $ — $ — $ — $ — Commercial Pass-through — — — — Interest-only 3,474,731 157,088 (345 ) 430 Loans held for investment, at fair value 9,030,908 8,909,037 68,508 113,646 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 7,334,475 7,191,462 (46,923 ) (67,029 ) 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 a senior securitization market for a similar pool of loans. 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 September 30, 2017 , the internally developed fair values of loan pools of $ 380 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 $ 6 million lower than the third party prices provided of $ 386 million . After review and discussion, the Company affirmed and valued the investments at the lower internally developed 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 September 30, 2017 and 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 Company determines 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. 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 September 30, 2017 and December 31, 2016 are presented below. September 30, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Counterparty and Cash Collateral, netting Total Assets: Non-Agency RMBS, at fair value $ — $ — $ 2,950,348 $ — $ 2,950,348 Agency MBS, at fair value — 4,354,872 — — 4,354,872 Loans held for investment, at fair value — — 13,538,052 — 13,538,052 Derivatives 4,864 22,771 — (5,110 ) 22,525 Liabilities: Securitized debt at fair value, collateralized by loans held for investment — — (9,683,062 ) — (9,683,062 ) Derivatives — (6,314 ) — 5,110 (1,204 ) Total $ 4,864 $ 4,371,329 $ 6,805,338 $ — $ 11,181,531 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 ) Total $ 1,785 $ 4,172,856 $ 5,142,619 $ 440 $ 9,317,700 The table below provides a summary of the changes in the fair value of securities classified as Level 3 at September 30, 2017 and December 31, 2016 . Fair Value Reconciliation, Level 3 For the Nine Months Ended, September 30, 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 71,116 5,835,799 (4,159,073 ) Principal payments (459,854 ) (1,298,856 ) 1,319,120 Sales and Settlements (68,164 ) 2,942 245,369 Accretion (amortization) of purchase discounts 92,201 (27,310 ) (4,247 ) Gains (losses) included in net income Other than temporary credit impairment losses (41,702 ) — — Realized gains (losses) on sales and settlements 12,031 — (48,014 ) Net unrealized gains (losses) included in income (14,179 ) 271,824 (95,120 ) Gains (losses) included in other comprehensive income Total unrealized gains (losses) for the period 22,724 — — Ending balance Level 3 assets $ 2,950,348 $ 13,538,052 $ (9,683,062 ) 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 no transfers to or from Level 3 for the quarter ended September 30, 2017 . There were $ 6 million of IOs transferred to Level 3 and no transfers out from Level 3, during the nine months ended September 30, 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 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 September 30, 2017 and December 31, 2016 follows: September 30, 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 4.6% 1% -45% 0% -60% 35% -95% 5.4% 1% -35% 0% -22% 35% -95% Senior interest-only 11.8% 4% -28% 0% -64% 35% -95% 12.5% 3% -30% 0% -22% 35% -95% Subordinated 5.9% 1% -20% 0% -21% 35% -77% 6.2% 1% -25% 0% -18% 0% -79% Subordinated interest-only 10.9% 10% -18% 0% -11% 35% -59% 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 September 30, 2017 and December 31, 2016 follows: September 30, 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% 1% - 22% 0% - 30% 35% - 70% 4.0% 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 Co

Repurchase Agreements

Repurchase Agreements	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 were: September 30, 2017 December 31, 2016 Repurchase agreements outstanding secured by: Agency MBS (in thousands) $ 3,096,233 $ 3,087,734 Non-agency MBS and Loans held for investment (in thousands) 3,613,588 2,513,169 Total: $ 6,709,821 $ 5,600,903 Average balance of Repurchase agreements secured by: Agency MBS (in thousands) $ 3,129,569 $ 4,159,651 Non-agency MBS and Loans held for investment (in thousands) 2,983,319 2,322,683 Total: $ 6,112,888 $ 6,482,334 Average borrowing rate of Repurchase agreements secured by: Agency MBS 1.39 % 0.90 % Non-agency MBS and Loans held for investment 3.25 % 3.05 % Average remaining maturity of Repurchase agreements secured by: Agency MBS 21 Days 32 Days Non-agency MBS and Loans held for investment 73 Days 98 Days Average original maturity of Repurchase agreements secured by: Agency MBS 76 Days 112 Days Non-agency MBS and Loans held for investment 109 Days 155 Days MBS pledged as collateral at fair value on Repurchase agreements: Agency MBS (in thousands) $ 3,332,640 $ 3,334,245 Non-agency MBS and Loans held for investment (in thousands) 4,817,669 3,699,621 Total: $ 8,150,309 $ 7,033,866 At September 30, 2017 and December 31, 2016 , the repurchase agreements collateralized by MBS and Loans held for investment had the following remaining maturities. September 30, 2017 December 31, 2016 (dollars in thousands) Overnight $ — $ — 1 to 29 days 3,777,160 2,947,604 30 to 59 days 1,591,370 958,956 60 to 89 days 330,186 407,625 90 to 119 days 28,798 559,533 Greater than or equal to 120 days 982,307 727,185 Total $ 6,709,821 $ 5,600,903 At September 30, 2017 , the Company had an amount at risk with Credit Suisse of 11% of its equity related to the collateral posted on repurchase agreements. As of September 30, 2017 the weighted average maturity of the repurchase agreements with Credit Suisse was 77 days and the amount at risk was $404 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 September 30, 2017 and December 31, 2016 .

Securitized Debt

Securitized Debt	9 Months Ended
	Sep. 30, 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 September 30, 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 $247 million and $350 million , respectively. At September 30, 2017 and December 31, 2016 , the debt carried a weighted average cost of financing equal to 5.88% and 5.21% , 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 quarter ended September 30, 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 quarter and nine months ended September 30, 2017 . During the quarter ended September 30, 2016, the Company acquired securitized debt collateralized by Non-Agency RMBS with an amortized cost balance of $4 million for $4 million . This transaction resulted in a net loss on the extinguishment of debt of $45 thousand . This loss is reflected in earnings for the quarter and nine months ended September 30, 2016. The following table presents the estimated principal repayment schedule of the securitized debt collateralized by Non-Agency RMBS at September 30, 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. September 30, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 62,165 $ 98,565 One to Three Years 50,055 82,563 Three to Five Years 21,013 23,854 Greater Than Five Years 5,913 31,973 Total $ 139,146 $ 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 September 30, 2017 and December 31, 2016 the Company’s securitized debt collateralized by loans held for investment had a principal balance of $9.6 billion and $7.1 billion , respectively. At September 30, 2017 and December 31, 2016 the total securitized debt collateralized by loans held for investment carried a weighted average cost of financing equal to 4.14% and 3.99% respectively. The debt matures between the years 2021 and 2065 . The Company did not acquire any securitized debt collateralized by loans during the quarters ended September 30, 2017 and 2016 . During the second quarter of 2017 , the Company acquired securitized debt collateralized by loans with an amortized cost balance of $197 million for $245 million . This transaction resulted in a net loss on the extinguishment of debt of $48 million , which is reflected in earnings for the nine months ended September 30, 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 first quarter of 2016 , the Company acquired securitized debt collateralized by loans with an amortized cost balance of $44 million for $46 million . This transaction resulted in a net loss on the extinguishment of debt of $2 million . This loss is reflected in earnings for the nine months ended September 30, 2016 . The following table presents the estimated principal repayment schedule of the securitized debt collateralized by loans held for investment at September 30, 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. September 30, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 1,856,397 $ 1,151,519 One to Three Years 2,907,977 1,841,808 Three to Five Years 2,163,866 1,423,706 Greater Than Five Years 2,630,039 2,477,123 Total $ 9,558,279 $ 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 September 30, 2017 . September 30, 2017 (dollars in thousands) Year Principal 2017 $ 811,395 2018 1,002,614 2019 416,722 2020 4,232,520 2021 2,961,293 Total $ 9,424,544

Consolidated Securitization Veh

Consolidated Securitization Vehicles and Other Variable Interest Entities	9 Months Ended
	Sep. 30, 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 September 30, 2017 , the Company’s Consolidated Statement of Financial Condition includes assets of consolidated VIEs with a carrying value of $14.8 billion and liabilities with a carrying value of $10.0 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 nine months ended September 30, 2017 , the Company acquired approximately $5.3 billion unpaid principal balance (excluding $550 million of loans held by a subsidiary of the Company) of seasoned residential subprime mortgage loans. The Company sold 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 acquisition. Consolidated Trusts (dollars in thousands) Assets: Loans held for investment, at fair value $ 5,353,955 Other Assets 36,795 Liabilities: Securitized debt at fair value (1) $ 4,171,458 (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 September 30, 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 September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 (dollars in thousands) Assets: Non-Agency RMBS, at fair value $ 1,646,762 $ 1,842,080 Loans held for investment, at fair value 13,011,319 8,753,653 Accrued interest receivable 76,327 57,153 Other assets 112,572 109,068 Liabilities: Securitized debt, collateralized by Non-Agency RMBS $ 233,113 $ 334,124 Securitized debt at fair value, collateralized by loans held for investment 9,683,062 6,941,097 Accrued interest payable 34,650 24,942 Other liabilities 3,612 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 Quarters Ended September 30, 2017 September 30, 2016 (dollars in thousands) Interest income, Assets of consolidated VIEs $ 241,195 $ 195,488 Interest expense, Non-recourse liabilities of VIEs 101,856 70,715 Net interest income $ 139,339 $ 124,773 Total other-than-temporary impairment losses $ (668 ) $ (21 ) Portion of loss recognized in other comprehensive income (loss) (10,108 ) (4,599 ) Net other-than-temporary credit impairment losses $ (10,776 ) $ (4,620 ) Servicing fees $ 10,492 $ 9,788 For the Nine Months Ended September 30, 2017 September 30, 2016 (dollars in thousands) Interest income, Assets of consolidated VIEs $ 668,621 $ 488,353 Interest expense, Non-recourse liabilities of VIEs 290,264 168,738 Net interest income $ 378,357 $ 319,615 Total other-than-temporary impairment losses $ (1,777 ) $ (866 ) Portion of loss recognized in other comprehensive income (loss) (35,720 ) (31,925 ) Net other-than-temporary credit impairment losses $ (37,497 ) $ (32,791 ) Servicing fees $ 30,970 $ 23,139 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 September 30, 2017 , ranged from less than $1 million to $51 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 September 30, 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	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 . September 30, 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 $ 3,373,400 Derivatives, at fair value, net $ 15,254 Derivatives, at fair value, net $ — Swaptions 482,000 Derivatives, at fair value, net 2,407 Derivatives, at fair value, net (1,204 ) Treasury Futures 619,700 Derivatives, at fair value, net 4,864 Derivatives, at fair value, net — Total $ 4,475,100 $ 22,525 $ (1,204 ) 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 September 30, 2017 September 30, 2016 (dollars in thousands) Interest Rate Swaps Net unrealized gains (losses) on derivatives $ 5,001 $ 13,395 Interest Rate Swaps Net realized gains (losses) on derivatives (3,491 ) (4,595 ) Treasury Futures Net unrealized gains (losses) on derivatives 3,467 12,149 Treasury Futures Net realized gains (losses) on derivatives (3,267 ) (7,823 ) Swaptions Net unrealized gains (losses) on derivatives 736 2,084 Swaptions Net realized gains (losses) on derivatives (1,083 ) (1,850 ) Other Derivative Assets Net unrealized gains (losses) on derivatives — — Other Derivative Assets Net realized gains (losses) on derivatives — — Total $ 1,363 $ 13,360 Net gains (losses) on derivatives Derivative Instruments Location on Consolidated Statements of September 30, 2017 September 30, 2016 (dollars in thousands) Interest Rate Swaps Net unrealized gains (losses) on derivatives $ 15,694 $ (36,840 ) Interest Rate Swaps Net realized gains (losses) on derivatives (1) (27,222 ) (84,571 ) Treasury Futures Net unrealized gains (losses) on derivatives 3,079 (4,259 ) Treasury Futures Net realized gains (losses) on derivatives (12,268 ) (28,797 ) Swaptions Net unrealized gains (losses) on derivatives 1,129 (10,283 ) Swaptions Net realized gains (losses) on derivatives (5,333 ) (5,615 ) Other Derivative Assets Net unrealized gains (losses) on derivatives — — Other Derivative Assets Net realized gains (losses) on derivatives — (567 ) Total $ (24,921 ) $ (170,932 ) (1) Includes loss on termination of interest rate swap of $16 million and $61 million for the nine months ended September 30, 2017 and 2016 , respectively. There were no swap terminations for the quarters ended September 30, 2017 and 2016 . The Company paid $16 million to terminate interest rate swaps with a notional value of $250 million during the nine months ended September 30, 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 nine months ended September 30, 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 September 30, 2017 was 1.71% and the weighted average receive rate was 1.39% . 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 September 30, 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 September 30, 2017 is approximately $6 million including accrued interest, which represents the maximum amount the Company would receive upon termination, which is fully collateralized.

Capital Stock

Capital Stock	9 Months Ended
	Sep. 30, 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 $7 million and $15 million , or $0.50 and $1.18 per preferred share during the quarter and nine months ended September 30, 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 $3 million and $9 million , or $0.50 and $1.50 per preferred share during the quarter and nine months ended September 30, 2017 . Common Stock Our Board of Directors adopted a program that authorizes repurchases of our common stock up to $350 million . 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 net asset value per common share. Generally, when the Company repurchases its common stock at a discount to its net asset value, the net asset value of its remaining shares of common stock outstanding increases. 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 quarter and nine months ended September 30, 2017 , and has $100 million in its share repurchase program that may be used to repurchase shares in the future. During the quarters and nine months ended September 30, 2017 , the Company declared regular dividends to common shareholders of $0.50 and $1.50 per share or $94 million and $282 million , respectively. During the quarters and nine months ended September 30, 2016 , the Company declared regular dividends to common shareholders of $0.48 and $1.44 per share or $91 million and $271 million , respectively, and a special dividend of $0.50 per share to common shareholders of $94 million . Earnings per share for the quarters and nine months ended September 30, 2017 , and 2016 , respectively, are computed as follows: For the Quarters Ended September 30, 2017 September 30, 2016 (dollars in thousands) Numerator: Net income available to common shareholders $ 129,832 $ 172,817 Effect of dilutive securities: — — Dilutive net income available to common shareholders $ 129,832 $ 172,817 Denominator: Weighted average basic shares 187,779,794 187,729,765 Effect of dilutive securities 412,317 190,027 Weighted average dilutive shares 188,192,111 187,919,792 Net income per average share attributable to common stockholders - Basic $ 0.69 $ 0.92 Net income per average share attributable to common stockholders - Diluted $ 0.69 $ 0.92 For the Nine Months Ended September 30, 2017 September 30, 2016 (dollars in thousands) Numerator: Net income available to common shareholders $ 392,977 $ 330,042 Effect of dilutive securities: — — Dilutive net income available to common shareholders $ 392,977 $ 330,042 Denominator: Weighted average basic shares 187,773,715 187,727,667 Effect of dilutive securities 403,042 190,027 Weighted average dilutive shares 188,176,757 187,917,694 Net income per average share attributable to common stockholders - Basic $ 2.09 $ 1.76 Net income per average share attributable to common stockholders - Diluted $ 2.09 $ 1.76

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 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 nine months ended September 30, 2017 and 2016 : September 30, 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 59,114 59,114 Amounts reclassified from AOCI 35,898 35,898 Net current period OCI 95,012 95,012 Balance as of September 30, 2017 $ 813,118 $ 813,118 September 30, 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 94,059 94,059 Amounts reclassified from AOCI 29,853 29,853 Net current period OCI 123,912 123,912 Balance as of September 30, 2016 $ 897,703 $ 897,703 The following table presents the details of the reclassifications from AOCI for the nine months ended September 30, 2017 and 2016 : September 30, 2017 September 30, 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 $ 7,778 $ 13,354 Net realized gains (losses) on sales of investments (43,676 ) (43,207 ) Net other-than-temporary credit impairment losses $ (35,898 ) $ (29,853 ) Income before income taxes — — Income taxes $ (35,898 ) $ (29,853 ) Net of tax

Equity Compensation, Employment

Equity Compensation, Employment Agreements and other Benefit Plans	9 Months Ended
	Sep. 30, 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 two 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 September 30, 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 first quarter of 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 one year 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 112 thousand and 266 thousand RSU awards during the first quarter of 2017 and 2016 , with a grant date fair value of $2 million and $3 million , respectively, which will be recognized as compensation expense on a straight-line basis over the three year vesting period. During the first quarter of 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 Company recognized stock based compensation expenses of $1 million and $620 thousand for the quarters ended September 30, 2017 , and 2016 , respectively. For the nine months ended September 30, 2017 , and 2016 , the stock based compensation expenses were $3 million and $ 1 million , 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 quarters ended September 30, 2017 and 2016 was $84 thousand and $78 thousand , respectively. For the nine months ended September 30, 2017 and 2016 , the 401(k) expense related to the Company's qualified plan was $299 thousand and $292 thousand , respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the quarter ended September 30, 2017 and the year ended December 31, 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 nine months ended September 30, 2017 and year ended December 31, 2016 . 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	9 Months Ended
	Sep. 30, 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 liabilities. The Company attempts to minimize credit risk through due diligence and asset selection by purchasing loans underwritten to agreed-upon specifications of selected originators as well as on-going 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 September 30, 2017 and December 31, 2016 . September 30, 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 $ (6,709,821 ) $ — $ (6,709,821 ) $ 8,150,308 $ 1,986 $ 1,442,473 Interest Rate Swaps - Gross Assets 20,364 (5,110 ) 15,254 — 46,339 61,593 Interest Rate Swaps - Gross Liabilities (5,110 ) 5,110 — — — — Treasury Futures - Gross Assets 4,864 — 4,864 — 997 5,861 Treasury Futures - Gross Liabilities — — — — — — Swaptions - Gross Assets 2,407 — 2,407 — — 2,407 Swaptions - Gross Liabilities (1,204 ) — (1,204 ) 1,279 — 75 Total Liabilities $ (6,688,500 ) $ — $ (6,688,500 ) $ 8,151,587 $ 49,322 $ 1,512,409 (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	9 Months Ended
	Sep. 30, 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	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Subsequent to September 30, 2017, $811 million of securitized debt issued by the Company was retired and new securitized debt was issued.

Summary of the Significant Ac25

Summary of the Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 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 significant 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 purpose 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 generally only be satisfied from each securitization vehicle’s respective asset pool. The assets of securitization entities are comprised of senior classes 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.
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.
Income Taxes	Income Taxes The Company does not have any unrecognized tax positions that would affect its financial statements or require disclosure.
Fair Value Disclosure	Fair Value Disclosure 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 this date 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.
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. Early adoption is allowed. The amendments in this update should be applied prospectively on or after the effective date. No disclosures are required at transition. The Company is not planning to early adopt and is currently evaluating what impact this update will have on the 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. Early adoption is allowed. The amendments in this update should be applied using a retrospective transition method to each period presented. The Company is not planning to early adopt and is currently evaluating what impact this update will have on the 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 Company did not elect to early adopt the provisions of this update. The Company is currently evaluating what impact this update will have on the consolidated financial statements. 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. Early adoption for certain provisions of the update is allowed. Any adjustment as a result of the adoption of this standard will be recorded as a cumulative-effect adjustment to beginning retained earnings as of the first period in which the guidance is adopted. The Company did not elect to early adopt the provisions of this update and is currently evaluating what impact this update will have on the consolidated financial statements.

Mortgage-Backed Securities (Tab

Mortgage-Backed Securities (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 . September 30, 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 $ 2,821,535 $ 224 $ (1,282,801 ) $ 1,538,958 $ 2,304,611 $ 765,653 $ — $ 765,653 Senior, interest-only 4,948,265 267,964 — 267,964 212,662 13,620 (68,922 ) (55,302 ) Subordinated 531,526 10,764 (188,169 ) 354,121 421,487 67,430 (64 ) 67,366 Subordinated, interest-only 256,286 12,968 — 12,968 11,588 860 (2,240 ) (1,380 ) Agency MBS Residential 2,316,838 128,388 — 2,445,226 2,428,112 7,606 (24,720 ) (17,114 ) Commercial 1,774,802 44,913 (4,732 ) 1,814,983 1,811,950 13,467 (16,500 ) (3,033 ) Interest-only 3,176,110 121,353 — 121,353 114,810 1,226 (7,769 ) (6,543 ) Total $ 15,825,362 $ 586,574 $ (1,475,702 ) $ 6,555,573 $ 7,305,220 $ 869,862 $ (120,215 ) $ 749,647 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 Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) (dollars in thousands) Balance at beginning of period $ 1,383,188 $ 1,714,592 $ 1,550,110 $ 1,742,744 Purchases 8,196 18,316 18,380 60,915 Yield income earned (66,042 ) (69,850 ) (202,618 ) (141,256 ) Reclassification (to) from non-accretable difference 53,884 (29,490 ) 15,777 (2,031 ) Sales and deconsolidation (17,755 ) (12,907 ) (20,178 ) (39,711 ) Balance at end of period $ 1,361,471 $ 1,620,661 $ 1,361,471 $ 1,620,661
Schedule of Non-Agency RMBS Having Deteriorated Credit When Acquired	The table below presents the outstanding principal balance and related amortized cost at September 30, 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 Quarter Ended For the Year Ended September 30, 2017 December 31, 2016 (dollars in thousands) Outstanding principal balance: Beginning of period $ 2,910,151 $ 3,550,698 End of period $ 2,772,746 $ 3,138,265 Amortized cost: Beginning of period $ 1,546,656 $ 1,958,726 End of period $ 1,449,531 $ 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 September 30, 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) of 2016, Form 10-K. September 30, 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 $ — $ — — $ — $ — — $ — $ — — Senior, interest-only 82,130 (15,487 ) 54 73,232 (53,435 ) 93 155,362 (68,922 ) 147 Subordinated 5,353 (64 ) 7 — — 1 5,353 (64 ) 8 Subordinated, interest-only 574 (331 ) 2 4,220 (1,909 ) 2 4,794 (2,240 ) 4 Agency MBS Residential 1,932,140 (17,187 ) 95 234,050 (7,533 ) 11 2,166,190 (24,720 ) 106 Commercial 876,181 (15,291 ) 241 30,311 (1,209 ) 1 906,492 (16,500 ) 242 Interest-only 29,250 (1,003 ) 12 58,031 (6,766 ) 21 87,281 (7,769 ) 33 Total $ 2,925,628 $ (49,363 ) 411 $ 399,844 $ (70,852 ) 129 $ 3,325,472 $ (120,215 ) 540 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 ) 1002
Other than Temporary Impairment, Credit Losses Recognized in Earnings	A summary of the OTTI included in earnings for the quarters and nine months ended September 30, 2017 and 2016 are presented below. For the Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) Total other-than-temporary impairment losses $ (784 ) $ (993 ) $ (4,245 ) $ (8,555 ) Portion of loss recognized in other comprehensive income (loss) (10,684 ) (10,581 ) (39,431 ) (34,652 ) Net other-than-temporary credit impairment losses $ (11,468 ) $ (11,574 ) $ (43,676 ) $ (43,207 ) 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 Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) Cumulative credit loss beginning balance $ 571,639 $ 546,187 $ 556,485 $ 529,112 Additions: Other-than-temporary impairments not previously recognized — 6,184 12,399 17,137 Reductions for securities sold or deconsolidated during the period (4,965 ) (2,630 ) (12,405 ) (6,890 ) Increases related to other-than-temporary impairments on securities with previously recognized other-than-temporary impairments 11,468 5,390 29,302 26,069 Reductions for increases in cash flows expected to be collected over the remaining life of the securities (3,241 ) (1,494 ) (10,880 ) (11,791 ) Cumulative credit impairment loss ending balance $ 574,901 $ 553,637 $ 574,901 $ 553,637
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 Nine Months Ended September 30, 2017 September 30, 2016 Loss Severity Weighted Average 67% 59% Range 28% - 89% 25% - 85% 60+ days delinquent Weighted Average 21% 21% Range 11% - 27% 0% - 40% Credit Enhancement (1) Weighted Average 15% 29% Range 0% - 50% 0% - 100% 3 Month CPR Weighted Average 13% 5% Range 2% - 24% 0% - 19% 12 Month CPR Weighted Average 13% 4% Range 4% - 19% 0% - 21% (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 September 30, 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 September 30, 2017 , IO MBS had a net unrealized loss of $63 million and had an amortized cost of $402 million . At December 31, 2016 , IO MBS had a net unrealized loss of $48 million and had an amortized cost of $458 million . The fair value of IOs at September 30, 2017 and December 31, 2016 was $339 million and $410 million , respectively. All changes in fair value of IOs are reflected in Net Income in the Consolidated Statements of Operations. September 30, 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 $ 765,653 $ — $ 765,653 $ — $ — $ — Senior, interest-only — 13,620 13,620 — (68,922 ) (68,922 ) Subordinated 63,348 4,082 67,430 (45 ) (19 ) (64 ) Subordinated, interest-only — 860 860 — (2,240 ) (2,240 ) Agency MBS Residential 7,606 — 7,606 (22,263 ) (2,457 ) (24,720 ) Commercial 13,339 128 13,467 (14,520 ) (1,980 ) (16,500 ) Interest-only — 1,226 1,226 — (7,769 ) (7,769 ) Total $ 849,946 $ 19,916 $ 869,862 $ (36,828 ) $ (83,387 ) $ (120,215 ) 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 September 30, 2017 and December 31, 2016 . September 30, 2017 Principal or Notional Value at Period-End (dollars in thousands) Weighted Average Amortized Cost Basis Weighted Average Fair Value Weighted Average Coupon Weighted Average Yield at Period-End (1) Non-Agency RMBS Senior $ 2,821,535 $ 54.54 $ 81.68 4.4 % 16.7 % Senior, interest-only 4,948,265 5.42 4.30 1.4 % 7.8 % Subordinated 531,526 66.62 79.30 4.1 % 9.2 % Subordinated, interest-only 256,286 5.06 4.52 1.0 % 8.4 % Agency MBS Residential pass-through 2,316,838 105.54 104.80 3.8 % 2.9 % Commercial pass-through 1,774,802 102.26 102.09 3.6 % 3.2 % Interest-only 3,176,110 3.82 3.61 0.7 % 3.5 % (1) Bond Equivalent Yield at period end. December 31, 2016 Principal or Notional Value at Period-End (dollars in thousands) Weighted Average Amortized Cost Basis Weighted Average Fair Value Weighted Average Coupon 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 September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 AAA 0.3 % 0.3 % AA 0.3 % 0.3 % A 0.6 % 0.7 % BBB 0.4 % 0.7 % BB 2.9 % 3.0 % B 2.1 % 3.9 % Below B 62.4 % 67.2 % Not Rated 31.0 % 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 September 30, 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. September 30, 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 $ 5,611 $ 757,644 $ 881,904 $ 659,452 $ 2,304,611 Senior interest-only 113 55,264 72,087 85,198 212,662 Subordinated — 83,242 183,777 154,468 421,487 Subordinated interest-only — 133 11,455 — 11,588 Agency MBS Residential — 32,666 2,395,446 — 2,428,112 Commercial — 46,263 16,817 1,748,870 1,811,950 Interest-only — 82,985 27,122 4,703 114,810 Total fair value $ 5,724 $ 1,058,197 $ 3,588,608 $ 2,652,691 $ 7,305,220 Amortized cost Non-Agency RMBS Senior $ 5,457 $ 549,443 $ 563,522 $ 420,536 $ 1,538,958 Senior interest-only 1,301 78,615 91,461 96,587 267,964 Subordinated — 67,164 152,048 134,909 354,121 Subordinated interest-only — 152 12,816 — 12,968 Agency MBS Residential — 33,035 2,412,191 — 2,445,226 Commercial — 47,639 17,216 1,750,128 1,814,983 Interest-only — 87,733 29,200 4,420 121,353 Total amortized cost $ 6,758 $ 863,781 $ 3,278,454 $ 2,406,580 $ 6,555,573 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 September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 Weighted average maturity (years) 20.9 21.6 Weighted average amortized loan to value (1) 65.1 % 66.5 % Weighted average FICO (2) 674 675 Weighted average loan balance (in thousands) $ 320 $ 319 Weighted average percentage owner occupied 83.9 % 83.2 % Weighted average percentage single family residence 65.7 % 65.8 % Weighted average current credit enhancement 2.2 % 2.3 % Weighted average geographic concentration of top four states CA 32.0 % CA 32.1 % NY 8.4 % FL 8.1 % FL 8.2 % 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 September 30, 2017 and December 31, 2016 . Origination Year September 30, 2017 December 31, 2016 2003 and prior 3.6 % 3.6 % 2004 4.8 % 4.2 % 2005 19.7 % 20.2 % 2006 39.8 % 38.0 % 2007 29.6 % 31.3 % 2008 1.7 % 1.8 % 2009 and later 0.8 % 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 quarters and nine months ended September 30, 2017 and 2016 are as follows: For the Quarters Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 (dollars in thousands) Proceeds from sales $ 598,752 $ 58,036 $ 772,496 $ 2,697,239 Gross realized gains 6,902 3,622 17,468 16,798 Gross realized losses (6,901 ) (543 ) (7,759 ) (9,763 ) Net realized gain (loss) $ 1 $ 3,079 $ 9,709 $ 7,035

Loans Held for Investment (Tabl

Loans Held for Investment (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 : For the Nine Months Ended For the Year Ended September 30, 2017 December 31, 2016 (dollars in thousands) Balance, beginning of period $ 8,753,653 $ 4,768,416 Purchases 5,835,799 4,897,370 Principal paydowns (1,298,856 ) (1,022,414 ) Sales and settlements 2,942 5,007 Net periodic accretion (amortization) (27,310 ) (41,363 ) Change in fair value 271,824 146,637 Balance, end of period $ 13,538,052 $ 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 September 30, 2017 December 31, 2016 2002 and prior 7.7 % 8.9 % 2003 6.9 % 5.2 % 2004 15.3 % 11.9 % 2005 20.9 % 20.5 % 2006 21.8 % 22.0 % 2007 18.8 % 20.9 % 2008 5.9 % 6.5 % 2009 0.6 % 0.6 % 2010 and later 2.1 % 3.5 % Total 100.0 % 100.0 %
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 September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Number of loans 147,340 95,155 Weighted average maturity (years) 18.8 19.8 Weighted average loan to value (1) 87.9 % 86.9 % Weighted average FICO (1) 629 627 Weighted average loan balance (in thousands) $ 90 $ 93 Weighted average percentage owner occupied 94.0 % 96.6 % Weighted average percentage single family residence 85.0 % 85.0 % Weighted average geographic concentration of top five states CA 9.2 % CA 10.0 % FL 7.1 % FL 6.7 % OH 6.2 % OH 6.5 % PA 5.6 % VA 5.9 % VA 5.4 % NC 5.1 % (1) As provided by the Trustee.
Schedule of Securitized Loans Held for Investment Carried at Fair Value Greater Than 30 Days Delinquent	The following table summarizes the outstanding principal balance of the residential loan portfolio which are 30 days delinquent and greater as reported by the servicer at September 30, 2017 and December 31, 2016 . 30 Days Delinquent 60 Days Delinquent 90+ Days Delinquent Bankruptcy Foreclosure REO Total Unpaid Principal/Notional (dollars in thousands) September 30, 2017 $462,865 $157,872 $294,458 $230,435 $172,129 $30,306 $1,348,065 $13,327,252 % of Unpaid Principal/Notional 3.5% 1.2% 2.2% 1.7% 1.3% 0.2% 10.1% December 31, 2016 $363,899 $140,495 $190,991 $207,364 $203,265 $40,709 $1,146,723 $8,868,783 % of Unpaid Principal/Notional 4.1% 1.6% 2.2% 2.3% 2.3% 0.5% 12.9%

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 and 2016 , respectively: September 30, 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 14,761 2,678 1,791 Senior, interest-only 4,948,265 212,662 1,784 (16,446 ) Subordinated, interest-only 256,286 11,588 1,048 475 Agency MBS Residential Pass-through $ 586,030 $ 614,758 $ (2,457 ) $ (2,457 ) Commercial Pass-through 407,943 410,013 (1,852 ) (1,852 ) Interest-only 3,176,110 114,810 (779 ) 831 Loans held for investment, at fair value 13,327,252 13,538,052 57,114 271,824 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 9,622,994 9,683,062 (38,494 ) (95,120 ) September 30, 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 20,671 8,257 7,551 Senior, interest-only 5,733,457 291,526 2,214 22,332 Subordinated, interest-only 269,868 13,498 1,289 3,288 Agency MBS Residential Pass-through $ — $ — $ — $ — Commercial Pass-through — — — — Interest-only 3,474,731 157,088 (345 ) 430 Loans held for investment, at fair value 9,030,908 8,909,037 68,508 113,646 Liabilities: Securitized debt at fair value, collateralized by loans held for investment 7,334,475 7,191,462 (46,923 ) (67,029 )
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 September 30, 2017 and December 31, 2016 are presented below. September 30, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Counterparty and Cash Collateral, netting Total Assets: Non-Agency RMBS, at fair value $ — $ — $ 2,950,348 $ — $ 2,950,348 Agency MBS, at fair value — 4,354,872 — — 4,354,872 Loans held for investment, at fair value — — 13,538,052 — 13,538,052 Derivatives 4,864 22,771 — (5,110 ) 22,525 Liabilities: Securitized debt at fair value, collateralized by loans held for investment — — (9,683,062 ) — (9,683,062 ) Derivatives — (6,314 ) — 5,110 (1,204 ) Total $ 4,864 $ 4,371,329 $ 6,805,338 $ — $ 11,181,531 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 ) Total $ 1,785 $ 4,172,856 $ 5,142,619 $ 440 $ 9,317,700
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 September 30, 2017 and December 31, 2016 . Fair Value Reconciliation, Level 3 For the Nine Months Ended, September 30, 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 71,116 5,835,799 (4,159,073 ) Principal payments (459,854 ) (1,298,856 ) 1,319,120 Sales and Settlements (68,164 ) 2,942 245,369 Accretion (amortization) of purchase discounts 92,201 (27,310 ) (4,247 ) Gains (losses) included in net income Other than temporary credit impairment losses (41,702 ) — — Realized gains (losses) on sales and settlements 12,031 — (48,014 ) Net unrealized gains (losses) included in income (14,179 ) 271,824 (95,120 ) Gains (losses) included in other comprehensive income Total unrealized gains (losses) for the period 22,724 — — Ending balance Level 3 assets $ 2,950,348 $ 13,538,052 $ (9,683,062 ) 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 September 30, 2017 and December 31, 2016 follows: September 30, 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% 1% - 22% 0% - 30% 35% - 70% 4.0% 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 September 30, 2017 and December 31, 2016 . September 30, 2017 (dollars in thousands) Level in Fair Value Hierarchy Carrying Amount Fair Value Repurchase agreements 2 6,709,821 6,727,850 Securitized debt, collateralized by Non-Agency RMBS 3 233,113 221,567 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 September 30, 2017 and December 31, 2016 follows: September 30, 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 4.6% 1% -45% 0% -60% 35% -95% 5.4% 1% -35% 0% -22% 35% -95% Senior interest-only 11.8% 4% -28% 0% -64% 35% -95% 12.5% 3% -30% 0% -22% 35% -95% Subordinated 5.9% 1% -20% 0% -21% 35% -77% 6.2% 1% -25% 0% -18% 0% -79% Subordinated interest-only 10.9% 10% -18% 0% -11% 35% -59% 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 September 30, 2017 and December 31, 2016 follows: September 30, 2017 December 31, 2016 Factor: Coupon Base Rate 4.7% 5.2% Actual 7.0% 7.1% FICO Base Rate 634 632 Actual 626 621 Loan-to-value (LTV) Base Rate 89% 87% Actual 88% 88% Loan Characteristics: Occupancy Owner Occupied 94% 97% Investor 2% 2% Secondary 4% 1% Property Type Single family 86% 86% Manufactured housing 5% 6% Multi-family/mixed use/other 9% 8%

Repurchase Agreements (Tables)

Repurchase Agreements (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 were: September 30, 2017 December 31, 2016 Repurchase agreements outstanding secured by: Agency MBS (in thousands) $ 3,096,233 $ 3,087,734 Non-agency MBS and Loans held for investment (in thousands) 3,613,588 2,513,169 Total: $ 6,709,821 $ 5,600,903 Average balance of Repurchase agreements secured by: Agency MBS (in thousands) $ 3,129,569 $ 4,159,651 Non-agency MBS and Loans held for investment (in thousands) 2,983,319 2,322,683 Total: $ 6,112,888 $ 6,482,334 Average borrowing rate of Repurchase agreements secured by: Agency MBS 1.39 % 0.90 % Non-agency MBS and Loans held for investment 3.25 % 3.05 % Average remaining maturity of Repurchase agreements secured by: Agency MBS 21 Days 32 Days Non-agency MBS and Loans held for investment 73 Days 98 Days Average original maturity of Repurchase agreements secured by: Agency MBS 76 Days 112 Days Non-agency MBS and Loans held for investment 109 Days 155 Days MBS pledged as collateral at fair value on Repurchase agreements: Agency MBS (in thousands) $ 3,332,640 $ 3,334,245 Non-agency MBS and Loans held for investment (in thousands) 4,817,669 3,699,621 Total: $ 8,150,309 $ 7,033,866 At September 30, 2017 and December 31, 2016 , the repurchase agreements collateralized by MBS and Loans held for investment had the following remaining maturities. September 30, 2017 December 31, 2016 (dollars in thousands) Overnight $ — $ — 1 to 29 days 3,777,160 2,947,604 30 to 59 days 1,591,370 958,956 60 to 89 days 330,186 407,625 90 to 119 days 28,798 559,533 Greater than or equal to 120 days 982,307 727,185 Total $ 6,709,821 $ 5,600,903

Securitized Debt (Tables)

Securitized Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Instrument [Line Items]
Schedule of Callable Debt	The following table presents the par value of the callable debt by year at September 30, 2017 . September 30, 2017 (dollars in thousands) Year Principal 2017 $ 811,395 2018 1,002,614 2019 416,722 2020 4,232,520 2021 2,961,293 Total $ 9,424,544
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 September 30, 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. September 30, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 62,165 $ 98,565 One to Three Years 50,055 82,563 Three to Five Years 21,013 23,854 Greater Than Five Years 5,913 31,973 Total $ 139,146 $ 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 September 30, 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. September 30, 2017 December 31, 2016 (dollars in thousands) Within One Year $ 1,856,397 $ 1,151,519 One to Three Years 2,907,977 1,841,808 Three to Five Years 2,163,866 1,423,706 Greater Than Five Years 2,630,039 2,477,123 Total $ 9,558,279 $ 6,894,156

Consolidated Securitization V31

Consolidated Securitization Vehicles and Other Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Consolidated Securitization Entities on Financial Condition	The table below reflects the assets and liabilities recorded in the Consolidated Statements of Financial Condition related to the consolidated VIEs as of September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 (dollars in thousands) Assets: Non-Agency RMBS, at fair value $ 1,646,762 $ 1,842,080 Loans held for investment, at fair value 13,011,319 8,753,653 Accrued interest receivable 76,327 57,153 Other assets 112,572 109,068 Liabilities: Securitized debt, collateralized by Non-Agency RMBS $ 233,113 $ 334,124 Securitized debt at fair value, collateralized by loans held for investment 9,683,062 6,941,097 Accrued interest payable 34,650 24,942 Other liabilities 3,612 2,742 The consolidation of these Trusts resulted in the addition of the following amounts, net of eliminations, at the time of acquisition. Consolidated Trusts (dollars in thousands) Assets: Loans held for investment, at fair value $ 5,353,955 Other Assets 36,795 Liabilities: Securitized debt at fair value (1) $ 4,171,458 (1) After the elimination of intercompany balances.
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 Quarters Ended September 30, 2017 September 30, 2016 (dollars in thousands) Interest income, Assets of consolidated VIEs $ 241,195 $ 195,488 Interest expense, Non-recourse liabilities of VIEs 101,856 70,715 Net interest income $ 139,339 $ 124,773 Total other-than-temporary impairment losses $ (668 ) $ (21 ) Portion of loss recognized in other comprehensive income (loss) (10,108 ) (4,599 ) Net other-than-temporary credit impairment losses $ (10,776 ) $ (4,620 ) Servicing fees $ 10,492 $ 9,788 For the Nine Months Ended September 30, 2017 September 30, 2016 (dollars in thousands) Interest income, Assets of consolidated VIEs $ 668,621 $ 488,353 Interest expense, Non-recourse liabilities of VIEs 290,264 168,738 Net interest income $ 378,357 $ 319,615 Total other-than-temporary impairment losses $ (1,777 ) $ (866 ) Portion of loss recognized in other comprehensive income (loss) (35,720 ) (31,925 ) Net other-than-temporary credit impairment losses $ (37,497 ) $ (32,791 ) Servicing fees $ 30,970 $ 23,139

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 . September 30, 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 $ 3,373,400 Derivatives, at fair value, net $ 15,254 Derivatives, at fair value, net $ — Swaptions 482,000 Derivatives, at fair value, net 2,407 Derivatives, at fair value, net (1,204 ) Treasury Futures 619,700 Derivatives, at fair value, net 4,864 Derivatives, at fair value, net — Total $ 4,475,100 $ 22,525 $ (1,204 ) 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 September 30, 2017 September 30, 2016 (dollars in thousands) Interest Rate Swaps Net unrealized gains (losses) on derivatives $ 5,001 $ 13,395 Interest Rate Swaps Net realized gains (losses) on derivatives (3,491 ) (4,595 ) Treasury Futures Net unrealized gains (losses) on derivatives 3,467 12,149 Treasury Futures Net realized gains (losses) on derivatives (3,267 ) (7,823 ) Swaptions Net unrealized gains (losses) on derivatives 736 2,084 Swaptions Net realized gains (losses) on derivatives (1,083 ) (1,850 ) Other Derivative Assets Net unrealized gains (losses) on derivatives — — Other Derivative Assets Net realized gains (losses) on derivatives — — Total $ 1,363 $ 13,360 Net gains (losses) on derivatives Derivative Instruments Location on Consolidated Statements of September 30, 2017 September 30, 2016 (dollars in thousands) Interest Rate Swaps Net unrealized gains (losses) on derivatives $ 15,694 $ (36,840 ) Interest Rate Swaps Net realized gains (losses) on derivatives (1) (27,222 ) (84,571 ) Treasury Futures Net unrealized gains (losses) on derivatives 3,079 (4,259 ) Treasury Futures Net realized gains (losses) on derivatives (12,268 ) (28,797 ) Swaptions Net unrealized gains (losses) on derivatives 1,129 (10,283 ) Swaptions Net realized gains (losses) on derivatives (5,333 ) (5,615 ) Other Derivative Assets Net unrealized gains (losses) on derivatives — — Other Derivative Assets Net realized gains (losses) on derivatives — (567 ) Total $ (24,921 ) $ (170,932 ) (1) Includes loss on termination of interest rate swap of $16 million and $61 million for the nine months ended September 30, 2017 and 2016 , respectively.

Capital Stock (Tables)

Capital Stock (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Schedule of Earnings Per Share	Earnings per share for the quarters and nine months ended September 30, 2017 , and 2016 , respectively, are computed as follows: For the Quarters Ended September 30, 2017 September 30, 2016 (dollars in thousands) Numerator: Net income available to common shareholders $ 129,832 $ 172,817 Effect of dilutive securities: — — Dilutive net income available to common shareholders $ 129,832 $ 172,817 Denominator: Weighted average basic shares 187,779,794 187,729,765 Effect of dilutive securities 412,317 190,027 Weighted average dilutive shares 188,192,111 187,919,792 Net income per average share attributable to common stockholders - Basic $ 0.69 $ 0.92 Net income per average share attributable to common stockholders - Diluted $ 0.69 $ 0.92 For the Nine Months Ended September 30, 2017 September 30, 2016 (dollars in thousands) Numerator: Net income available to common shareholders $ 392,977 $ 330,042 Effect of dilutive securities: — — Dilutive net income available to common shareholders $ 392,977 $ 330,042 Denominator: Weighted average basic shares 187,773,715 187,727,667 Effect of dilutive securities 403,042 190,027 Weighted average dilutive shares 188,176,757 187,917,694 Net income per average share attributable to common stockholders - Basic $ 2.09 $ 1.76 Net income per average share attributable to common stockholders - Diluted $ 2.09 $ 1.76

Accumulated Other Comprehensi34

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 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 nine months ended September 30, 2017 and 2016 : September 30, 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 59,114 59,114 Amounts reclassified from AOCI 35,898 35,898 Net current period OCI 95,012 95,012 Balance as of September 30, 2017 $ 813,118 $ 813,118 September 30, 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 94,059 94,059 Amounts reclassified from AOCI 29,853 29,853 Net current period OCI 123,912 123,912 Balance as of September 30, 2016 $ 897,703 $ 897,703
Schedule of Reclassifications from AOCI	The following table presents the details of the reclassifications from AOCI for the nine months ended September 30, 2017 and 2016 : September 30, 2017 September 30, 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 $ 7,778 $ 13,354 Net realized gains (losses) on sales of investments (43,676 ) (43,207 ) Net other-than-temporary credit impairment losses $ (35,898 ) $ (29,853 ) Income before income taxes — — Income taxes $ (35,898 ) $ (29,853 ) Net of tax

Credit Risk and Interest Rate35

Credit Risk and Interest Rate Risk (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 and December 31, 2016 . September 30, 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 $ (6,709,821 ) $ — $ (6,709,821 ) $ 8,150,308 $ 1,986 $ 1,442,473 Interest Rate Swaps - Gross Assets 20,364 (5,110 ) 15,254 — 46,339 61,593 Interest Rate Swaps - Gross Liabilities (5,110 ) 5,110 — — — — Treasury Futures - Gross Assets 4,864 — 4,864 — 997 5,861 Treasury Futures - Gross Liabilities — — — — — — Swaptions - Gross Assets 2,407 — 2,407 — — 2,407 Swaptions - Gross Liabilities (1,204 ) — (1,204 ) 1,279 — 75 Total Liabilities $ (6,688,500 ) $ — $ (6,688,500 ) $ 8,151,587 $ 49,322 $ 1,512,409 (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

Organization - Narrative (Detai

Organization - Narrative (Detail)	9 Months Ended
	Sep. 30, 2017subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of wholly owned direct subsidiaries	8

Summary of the Significant Ac37

Summary of the Significant Accounting Policies (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Penalties and interest accrued	$ 0	$ 0

Mortgage-Backed Securities - Su

Mortgage-Backed Securities - Summary (Detail) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Principal or Notional Value	$ 15,825,362	$ 17,062,076
Total Premium	586,574	662,686
Total Discount	(1,475,702)	(1,627,480)
Amortized Cost	6,555,573	6,825,525
Fair Value	7,305,220	7,497,817
Gross Unrealized Gains	869,862	841,967
Gross Unrealized Losses	(120,215)	(169,675)
Net Unrealized Gain/(Loss)	749,647	672,292
Non-Agency RMBS - Senior
Investment Holdings [Line Items]
Principal or Notional Value	2,821,535	3,190,947
Total Premium	224	231
Total Discount	(1,282,801)	(1,412,058)
Amortized Cost	1,538,958	1,779,120
Fair Value	2,304,611	2,511,003
Gross Unrealized Gains	765,653	732,133
Gross Unrealized Losses	0	(250)
Net Unrealized Gain/(Loss)	765,653	731,883
Non-Agency RMBS - Senior interest-only
Investment Holdings [Line Items]
Principal or Notional Value		5,648,339
Total Premium	267,964	292,396
Total Discount	0	0
Amortized Cost	267,964	292,396
Fair Value	212,662	253,539
Gross Unrealized Gains	13,620	18,674
Gross Unrealized Losses	(68,922)	(57,531)
Net Unrealized Gain/(Loss)	(55,302)	(38,857)
Non-Agency RMBS - Subordinated
Investment Holdings [Line Items]
Principal or Notional Value	531,526	673,259
Total Premium	10,764	16,352
Total Discount	(188,169)	(212,734)
Amortized Cost	354,121	476,877
Fair Value	421,487	553,498
Gross Unrealized Gains	67,430	77,857
Gross Unrealized Losses	(64)	(1,236)
Net Unrealized Gain/(Loss)	67,366	76,621
Non-Agency RMBS - Subordinated interest-only
Investment Holdings [Line Items]
Principal or Notional Value		266,927
Total Premium	12,968	13,878
Total Discount	0	0
Amortized Cost	12,968	13,878
Fair Value	11,588	12,024
Gross Unrealized Gains	860	0
Gross Unrealized Losses	(2,240)	(1,854)
Net Unrealized Gain/(Loss)	(1,380)	(1,854)
Agency MBS - Residential
Investment Holdings [Line Items]
Principal or Notional Value	2,316,838	2,594,570
Total Premium	128,388	149,872
Total Discount	0	0
Amortized Cost	2,445,226	2,744,442
Fair Value	2,428,112	2,705,978
Gross Unrealized Gains	7,606	11,235
Gross Unrealized Losses	(24,720)	(49,699)
Net Unrealized Gain/(Loss)	(17,114)	(38,464)
Agency MBS - Commercial
Investment Holdings [Line Items]
Principal or Notional Value	1,774,802	1,331,543
Total Premium	44,913	37,782
Total Discount	(4,732)	(2,688)
Amortized Cost	1,814,983	1,366,637
Fair Value	1,811,950	1,316,975
Gross Unrealized Gains	13,467	175
Gross Unrealized Losses	(16,500)	(49,837)
Net Unrealized Gain/(Loss)	(3,033)	(49,662)
Agency MBS - Interest-only
Investment Holdings [Line Items]
Principal or Notional Value	3,176,110	3,356,491
Total Premium	121,353	152,175
Total Discount	0	0
Amortized Cost	121,353	152,175
Fair Value	114,810	144,800
Gross Unrealized Gains	1,226	1,893
Gross Unrealized Losses	(7,769)	(9,268)
Net Unrealized Gain/(Loss)	$ (6,543)	$ (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	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 1,383,188	$ 1,714,592	$ 1,550,110	$ 1,742,744
Purchases	8,196	18,316	18,380	60,915
Yield income earned	(66,042)	(69,850)	(202,618)	(141,256)
Reclassification (to) from non-accretable difference	53,884	(29,490)	15,777	(2,031)
Sales and deconsolidation	(17,755)	(12,907)	(20,178)	(39,711)
Balance at end of period	$ 1,361,471	$ 1,620,661	$ 1,361,471	$ 1,620,661

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	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Outstanding principal balance:
Beginning of period	$ 2,910,151	$ 3,138,265	$ 3,550,698
End of period	2,772,746	2,910,151	3,138,265
Amortized cost:
Beginning of period	1,546,656	1,695,079	1,958,726
End of period	$ 1,449,531	$ 1,546,656	$ 1,695,079

Mortgage-Backed Securities - Un

Mortgage-Backed Securities - Unrealized Loss Positions (Detail) - Residential Mortgage-Backed Securities $ in Thousands	Sep. 30, 2017USD ($)security	Dec. 31, 2016USD ($)security
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 2,925,628	$ 3,815,885
Estimated Fair Value Unrealized Loss Position for 12 Months or More	399,844	252,257
Estimated Fair Value Total	3,325,472	4,068,142
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(49,363)	(110,548)
Unrealized Losses Unrealized Loss Position for 12 Months or More	(70,852)	(59,127)
Unrealized Losses Total	$ (120,215)	$ (169,675)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	411	846
Number of Securities Unrealized Loss Position for 12 Months or More | security	129	156
Number of Securities in continuous loss position | security	540	1,002
Non-Agency RMBS - Senior
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 0	$ 12,384
Estimated Fair Value Unrealized Loss Position for 12 Months or More	0	0
Estimated Fair Value Total	0	12,384
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	0	(250)
Unrealized Losses Unrealized Loss Position for 12 Months or More	0	0
Unrealized Losses Total	$ 0	$ (250)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	0	3
Number of Securities Unrealized Loss Position for 12 Months or More | security	0	0
Number of Securities in continuous loss position | security	0	3
Non-Agency RMBS - Senior interest-only
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 82,130	$ 96,399
Estimated Fair Value Unrealized Loss Position for 12 Months or More	73,232	78,516
Estimated Fair Value Total	155,362	174,915
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(15,487)	(13,600)
Unrealized Losses Unrealized Loss Position for 12 Months or More	(53,435)	(43,931)
Unrealized Losses Total	$ (68,922)	$ (57,531)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	54	62
Number of Securities Unrealized Loss Position for 12 Months or More | security	93	86
Number of Securities in continuous loss position | security	147	148
Non-Agency RMBS - Subordinated
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 5,353	$ 56,015
Estimated Fair Value Unrealized Loss Position for 12 Months or More	0	2,826
Estimated Fair Value Total	5,353	58,841
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(64)	(412)
Unrealized Losses Unrealized Loss Position for 12 Months or More	0	(824)
Unrealized Losses Total	$ (64)	$ (1,236)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	7	7
Number of Securities Unrealized Loss Position for 12 Months or More | security	1	4
Number of Securities in continuous loss position | security	8	11
Non-Agency RMBS - Subordinated interest-only
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 574	$ 748
Estimated Fair Value Unrealized Loss Position for 12 Months or More	4,220	11,276
Estimated Fair Value Total	4,794	12,024
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(331)	(230)
Unrealized Losses Unrealized Loss Position for 12 Months or More	(1,909)	(1,624)
Unrealized Losses Total	$ (2,240)	$ (1,854)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	2	2
Number of Securities Unrealized Loss Position for 12 Months or More | security	2	3
Number of Securities in continuous loss position | security	4	5
Agency MBS - Residential
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 1,932,140	$ 2,338,910
Estimated Fair Value Unrealized Loss Position for 12 Months or More	234,050	54,943
Estimated Fair Value Total	2,166,190	2,393,853
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(17,187)	(48,084)
Unrealized Losses Unrealized Loss Position for 12 Months or More	(7,533)	(1,615)
Unrealized Losses Total	$ (24,720)	$ (49,699)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	95	106
Number of Securities Unrealized Loss Position for 12 Months or More | security	11	1
Number of Securities in continuous loss position | security	106	107
Agency MBS - Commercial
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 876,181	$ 1,247,923
Estimated Fair Value Unrealized Loss Position for 12 Months or More	30,311	51,733
Estimated Fair Value Total	906,492	1,299,656
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(15,291)	(45,802)
Unrealized Losses Unrealized Loss Position for 12 Months or More	(1,209)	(4,035)
Unrealized Losses Total	$ (16,500)	$ (49,837)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	241	646
Number of Securities Unrealized Loss Position for 12 Months or More | security	1	46
Number of Securities in continuous loss position | security	242	692
Agency MBS - Interest-only
Estimated Fair Value
Estimated Fair Value Unrealized Loss Position for Less than 12 Months	$ 29,250	$ 63,506
Estimated Fair Value Unrealized Loss Position for 12 Months or More	58,031	52,963
Estimated Fair Value Total	87,281	116,469
Unrealized Losses
Unrealized Losses Unrealized Loss Position for Less than 12 Months	(1,003)	(2,170)
Unrealized Losses Unrealized Loss Position for 12 Months or More	(6,766)	(7,098)
Unrealized Losses Total	$ (7,769)	$ (9,268)
Number of Securities
Number of Securities Unrealized Loss Position for Less than 12 Months | security	12	20
Number of Securities Unrealized Loss Position for 12 Months or More | security	21	16
Number of Securities in continuous loss position | security	33	36

Mortgage-Backed Securities - In

Mortgage-Backed Securities - Investment Holdings - Narrative (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Interest-only
Investment Holdings [Line Items]
Interest-only RMBS, net unrealized gain (loss)	$ (63,000)		$ (63,000)		$ (48,000)
Interest-only RMBS, amortized cost	402,000		402,000		458,000
Interest-only RMBS, fair value	339,000		339,000		410,000
Residential Mortgage-Backed Securities
Investment Holdings [Line Items]
Gross unrealized loss	120,215		120,215		169,675
Interest-only RMBS, net unrealized gain (loss)	749,647		749,647		672,292
Interest-only RMBS, amortized cost	6,555,573		6,555,573		6,825,525
Agency RMBS - Pass-through
Investment Holdings [Line Items]
Gross unrealized loss	37,000		37,000		100,000
Non-agency MBS
Investment Holdings [Line Items]
Gross unrealized loss	$ 45		$ 45		$ 485
Non-Agency RMBS Deemed To Be Equivalent To Alt-A Quality
Investment Holdings [Line Items]
Percentage in Alt-A collateral	69.00%		69.00%		68.00%
Non Agency Residential MBS Deemed To Be Equivalent To Prime Quality
Investment Holdings [Line Items]
Percentage in prime collateral	11.00%		11.00%		14.00%
Re-REMIC Security
Investment Holdings [Line Items]
Fair value of securities exchanged	$ 36,000	$ 30,000	$ 63,000	$ 47,000
Gain (loss) on sale of investments	$ 4,000	$ 2,000	$ 9,000	$ 1,000
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) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Total other-than-temporary impairment losses	$ (784)	$ (993)	$ (4,245)	$ (8,555)
Portion of loss recognized in other comprehensive income (loss)	(10,684)	(10,581)	(39,431)	(34,652)
Net other-than-temporary credit impairment losses	$ (11,468)	$ (11,574)	$ (43,676)	$ (43,207)

Mortgage-Backed Securities - 44

Mortgage-Backed Securities - Non-Agency Securities Credit Losses (Detail) - Non-agency MBS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Cumulative credit loss beginning balance	$ 571,639	$ 546,187	$ 556,485	$ 529,112
Additions:
Other-than-temporary impairments not previously recognized	0	6,184	12,399	17,137
Reductions for securities sold or deconsolidated during the period	(4,965)	(2,630)	(12,405)	(6,890)
Increases related to other-than-temporary impairments on securities with previously recognized other-than-temporary impairments	11,468	5,390	29,302	26,069
Reductions for increases in cash flows expected to be collected over the remaining life of the securities	(3,241)	(1,494)	(10,880)	(11,791)
Cumulative credit impairment loss ending balance	$ 574,901	$ 553,637	$ 574,901	$ 553,637

Mortgage-Backed Securities - OT

Mortgage-Backed Securities - OTTI - Significant Inputs and Assumptions (Detail) - Non-agency MBS	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Weighted Average
Investment Holdings [Line Items]
Loss Severity	67.00%	59.00%
60 days delinquent	21.00%	21.00%
Credit Enhancement	15.00%	29.00%
3 Month CPR	13.00%	5.00%
12 Month CPR	13.00%	4.00%
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	2.00%	0.00%
12 Month CPR	4.00%	0.00%
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%	19.00%
12 Month CPR	19.00%	21.00%

Mortgage-Backed Securities - Gr

Mortgage-Backed Securities - Gross Unrealized Gains (Losses) (Detail) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	$ 849,946	$ 818,127
Gross Unrealized Gain Included in Cumulative Earnings	19,916	23,840
Total Gross Unrealized Gain	869,862	841,967
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(36,828)	(100,021)
Gross Unrealized Loss Included in Cumulative Earnings	(83,387)	(69,654)
Total Gross Unrealized Loss	(120,215)	(169,675)
Non-Agency RMBS - Senior
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	765,653	732,133
Gross Unrealized Gain Included in Cumulative Earnings	0	0
Total Gross Unrealized Gain	765,653	732,133
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	(250)
Gross Unrealized Loss Included in Cumulative Earnings	0	0
Total Gross Unrealized Loss	0	(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	13,620	18,674
Total Gross Unrealized Gain	13,620	18,674
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(68,922)	(57,531)
Total Gross Unrealized Loss	(68,922)	(57,531)
Non-Agency RMBS - Subordinated
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	63,348	74,584
Gross Unrealized Gain Included in Cumulative Earnings	4,082	3,273
Total Gross Unrealized Gain	67,430	77,857
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(45)	(235)
Gross Unrealized Loss Included in Cumulative Earnings	(19)	(1,001)
Total Gross Unrealized Loss	(64)	(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	860	0
Total Gross Unrealized Gain	860	0
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(2,240)	(1,854)
Total Gross Unrealized Loss	(2,240)	(1,854)
Agency MBS - Residential
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	7,606	11,235
Gross Unrealized Gain Included in Cumulative Earnings	0	0
Total Gross Unrealized Gain	7,606	11,235
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(22,263)	(49,699)
Gross Unrealized Loss Included in Cumulative Earnings	(2,457)	0
Total Gross Unrealized Loss	(24,720)	(49,699)
Agency MBS - Commercial
Investment Holdings [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	13,339	175
Gross Unrealized Gain Included in Cumulative Earnings	128	0
Total Gross Unrealized Gain	13,467	175
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(14,520)	(49,837)
Gross Unrealized Loss Included in Cumulative Earnings	(1,980)	0
Total Gross Unrealized Loss	(16,500)	(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	1,226	1,893
Total Gross Unrealized Gain	1,226	1,893
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(7,769)	(9,268)
Total Gross Unrealized Loss	$ (7,769)	$ (9,268)

Mortgage-Backed Securities - Co

Mortgage-Backed Securities - Collateral Characteristics (Detail) - Residential Mortgage-Backed Securities $ in Thousands	Sep. 30, 2017USD ($)$ / security	Dec. 31, 2016USD ($)$ / security
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 15,825,362	$ 17,062,076
Non-Agency RMBS - Senior
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 2,821,535	$ 3,190,947
Weighted Average Amortized Cost Basis	54.54	55.76
Weighted Average Fair Value	81.68	78.69
Weighted Average Coupon	4.40%	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 | $		$ 5,648,339
Weighted Average Amortized Cost Basis	5.42	5.18
Weighted Average Fair Value	4.30	4.49
Weighted Average Coupon	1.40%	1.50%
Weighted Average Yield at Period-End	7.80%	11.70%
Non-Agency RMBS - Subordinated
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 531,526	$ 673,259
Weighted Average Amortized Cost Basis	66.62	70.83
Weighted Average Fair Value	79.30	82.21
Weighted Average Coupon	4.10%	3.80%
Weighted Average Yield at Period-End	9.20%	9.20%
Non-Agency RMBS - Subordinated interest-only
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $		$ 266,927
Weighted Average Amortized Cost Basis	5.06	5.20
Weighted Average Fair Value	4.52	4.50
Weighted Average Coupon	1.00%	1.10%
Weighted Average Yield at Period-End	8.40%	13.50%
Agency MBS - Residential
Investment Holdings [Line Items]
Principal or Notional Value at Period-End | $	$ 2,316,838	$ 2,594,570
Weighted Average Amortized Cost Basis	105.54	105.78
Weighted Average Fair Value	104.80	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 | $	$ 1,774,802	$ 1,331,543
Weighted Average Amortized Cost Basis	102.26	102.64
Weighted Average Fair Value	102.09	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 | $	$ 3,176,110	$ 3,356,491
Weighted Average Amortized Cost Basis	3.82	4.53
Weighted Average Fair Value	3.61	4.31
Weighted Average Coupon	0.70%	0.80%
Weighted Average Yield at Period-End	3.50%	3.50%

Mortgage-Backed Securities - Cr

Mortgage-Backed Securities - Credit Ratings (Detail) - Non-agency MBS	Sep. 30, 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	0.40%	0.70%
BB
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	2.90%	3.00%
B
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	2.10%	3.90%
Below B
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	62.40%	67.20%
Not Rated
Credit Derivatives [Line Items]
Percentage of RMBS portfolio at fair value, by credit rating	31.00%	23.90%

Mortgage-Backed Securities - Ma

Mortgage-Backed Securities - Maturities (Detail) - Residential Mortgage-Backed Securities - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair value
Less than one year, at fair value	$ 5,724	$ 26,029
Greater than one year and less than five years, at fair value	1,058,197	1,194,654
Greater than five years and less than ten years, at fair value	3,588,608	3,990,091
Greater than ten years, at fair value	2,652,691	2,287,043
Total maturities, at fair value	7,305,220	7,497,817
Amortized cost
Less than one year, at amortized cost	6,758	23,415
Greater than one year and less than five years, at amortized cost	863,781	1,094,684
Greater than five years and less than ten years, at amortized cost	3,278,454	3,605,434
Greater than ten years, at amortized cost	2,406,580	2,101,992
Amortized Cost	6,555,573	6,825,525
Non-Agency RMBS - Senior
Fair value
Less than one year, at fair value	5,611	25,612
Greater than one year and less than five years, at fair value	757,644	508,979
Greater than five years and less than ten years, at fair value	881,904	1,267,000
Greater than ten years, at fair value	659,452	709,412
Total maturities, at fair value	2,304,611	2,511,003
Amortized cost
Less than one year, at amortized cost	5,457	21,423
Greater than one year and less than five years, at amortized cost	549,443	403,250
Greater than five years and less than ten years, at amortized cost	563,522	868,624
Greater than ten years, at amortized cost	420,536	485,823
Amortized Cost	1,538,958	1,779,120
Non-Agency RMBS - Senior interest-only
Fair value
Less than one year, at fair value	113	417
Greater than one year and less than five years, at fair value	55,264	37,796
Greater than five years and less than ten years, at fair value	72,087	115,780
Greater than ten years, at fair value	85,198	99,546
Total maturities, at fair value	212,662	253,539
Amortized cost
Less than one year, at amortized cost	1,301	1,992
Greater than one year and less than five years, at amortized cost	78,615	50,252
Greater than five years and less than ten years, at amortized cost	91,461	134,642
Greater than ten years, at amortized cost	96,587	105,510
Amortized Cost	267,964	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	83,242	94,793
Greater than five years and less than ten years, at fair value	183,777	238,630
Greater than ten years, at fair value	154,468	220,075
Total maturities, at fair value	421,487	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	67,164	76,287
Greater than five years and less than ten years, at amortized cost	152,048	195,538
Greater than ten years, at amortized cost	134,909	205,052
Amortized Cost	354,121	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	133	0
Greater than five years and less than ten years, at fair value	11,455	12,024
Greater than ten years, at fair value	0	0
Total maturities, at fair value	11,588	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	152	0
Greater than five years and less than ten years, at amortized cost	12,816	13,878
Greater than ten years, at amortized cost	0	0
Amortized Cost	12,968	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	32,666	429,869
Greater than five years and less than ten years, at fair value	2,395,446	2,276,109
Greater than ten years, at fair value	0	0
Total maturities, at fair value	2,428,112	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	33,035	438,270
Greater than five years and less than ten years, at amortized cost	2,412,191	2,306,172
Greater than ten years, at amortized cost	0	0
Amortized Cost	2,445,226	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	46,263	47,354
Greater than five years and less than ten years, at fair value	16,817	16,833
Greater than ten years, at fair value	1,748,870	1,252,788
Total maturities, at fair value	1,811,950	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	47,639	49,027
Greater than five years and less than ten years, at amortized cost	17,216	17,247
Greater than ten years, at amortized cost	1,750,128	1,300,363
Amortized Cost	1,814,983	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	82,985	75,863
Greater than five years and less than ten years, at fair value	27,122	63,715
Greater than ten years, at fair value	4,703	5,222
Total maturities, at fair value	114,810	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	87,733	77,598
Greater than five years and less than ten years, at amortized cost	29,200	69,333
Greater than ten years, at amortized cost	4,420	5,244
Amortized Cost	$ 121,353	$ 152,175

Mortgage-Backed Securities - Ge

Mortgage-Backed Securities - Geographical and Other Statistics (Detail) - Non-agency MBS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Weighted average maturity (years)	20 years 10 months 24 days	21 years 7 months 6 days
Weighted average amortized loan to value	65.10%	66.50%
Weighted average FICO	674	675
Weighted average loan balance (in thousands)	$ 320	$ 319
Weighted average percentage owner occupied	83.90%	83.20%
Weighted average percentage single family residence	65.70%	65.80%
Weighted average current credit enhancement	2.20%	2.30%
California
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	32.00%	32.10%
New York
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	8.40%	7.90%
Florida
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	8.20%	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	Sep. 30, 2017	Dec. 31, 2016
Origination Year as a Percentage of Outstanding Principal Balance:
2003 (and prior)	3.60%	3.60%
2,004	4.80%	4.20%
2,005	19.70%	20.20%
2,006	39.80%	38.00%
2,007	29.60%	31.30%
2,008	1.70%	1.80%
2009 and later	0.80%	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		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$ 598,752	$ 58,036	$ 772,496	$ 2,697,239
Gross realized gains	6,902	3,622	17,468	16,798
Gross realized losses	(6,901)	(543)	(7,759)	(9,763)
Net realized gain (loss)	$ 1	$ 3,079	$ 9,709	$ 7,035

Loans Held for Investment - Nar

Loans Held for Investment - Narrative (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Securitized debt loans held for investment at cost	$ 13,100,000	$ 8,600,000
Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
90 and over days delinquent	591,000	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]
90 and over days delinquent	294,458	190,991
Real estate held-for-sale	$ 10,000	$ 13,000

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	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance, beginning of period	$ 8,753,653	$ 4,768,416
Purchases	5,835,799	4,897,370
Principal paydowns	(1,298,856)	(1,022,414)
Sales and settlements	2,942	5,007
Net periodic accretion (amortization)	(27,310)	(41,363)
Change in fair value	271,824	146,637
Balance, end of period	$ 13,538,052	$ 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	Sep. 30, 2017	Dec. 31, 2016
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
2002 and prior	7.70%	8.90%
2,003	6.90%	5.20%
2,004	15.30%	11.90%
2,005	20.90%	20.50%
2,006	21.80%	22.00%
2,007	18.80%	20.90%
2,008	5.90%	6.50%
2,009	0.60%	0.60%
2010 and later	2.10%	3.50%
Total	100.00%	100.00%

Loans Held for Investment - Col

Loans Held for Investment - Collateral Characteristics (Detail) - Loans Held for Investment at Fair Value - Seasoned Subprime Residential Mortgage Loans $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Number of loans | loan	147,340	95,155
Weighted average maturity (years)	18 years 9 months 18 days	19 years 9 months 18 days
Weighted average loan to value	87.90%	86.90%
Weighted average FICO	629	627
Weighted average loan balance (in thousands) | $	$ 90	$ 93
Weighted average percentage owner occupied	94.00%	96.60%
Weighted average percentage single family residence	85.00%	85.00%
California
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	9.20%	10.00%
Florida
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	7.10%	6.70%
Ohio
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	6.20%	6.50%
Pennsylvania
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	5.60%
Virginia
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Weighted average geographic concentration of top four states	5.40%	5.90%
North Carolina
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 - Agi

Loans Held for Investment - Aging (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
Unpaid Principal/Notional	$ 13,327,252	$ 8,868,783
Loans Held for Investment at Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
30 Days Delinquent	462,865	363,899
60 Days Delinquent	157,872	140,495
90 and Over Days Delinquent	294,458	190,991
Bankruptcy	230,435	207,364
Foreclosure	172,129	203,265
REO	30,306	40,709
Total	$ 1,348,065	$ 1,146,723
% of Unpaid Principal/Notional	10.10%	12.90%
% of Unpaid Principal/Notional, Bankruptcy	1.70%	2.30%
% of Unpaid Principal/Notional, Foreclosures	1.30%	2.30%
% of Unpaid Principal/Notional, REO	0.20%	0.50%
30 Days Delinquent | Loans Held for Investment at Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
% of Unpaid Principal/Notional	3.50%	4.10%
60 Days Delinquent | Loans Held for Investment at Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
% of Unpaid Principal/Notional	1.20%	1.60%
90 Days Delinquent | Loans Held for Investment at Fair Value | Seasoned Subprime Residential Mortgage Loans
Securitized Loans Held For Investment By Consolidated Variable Interest Entities [Line Items]
% of Unpaid Principal/Notional	2.20%	2.20%

Fair Value Measurements - Level

Fair Value Measurements - Level of Fair Value (Detail) $ in Thousands	Sep. 30, 2017USD ($)loan	Dec. 31, 2016USD ($)loan	Sep. 30, 2016USD ($)
Assets:
Non-Agency RMBS, at fair value	$ 2,950,348	$ 3,330,063
Agency MBS, at fair value	4,354,872	4,167,754
Loans held for investment, at fair value	13,538,052	8,753,653	$ 8,909,037
Derivatives, at fair value, net	22,525	9,677
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	(9,683,062)	(6,941,097)	$ (7,191,462)
Derivative, Total	(1,204)	(2,350)
Fair Value, Measurements, Recurring
Assets:
Non-Agency RMBS, at fair value	2,950,348	3,330,063
Agency MBS, at fair value	4,354,872	4,167,754
Loans held for investment, at fair value	13,538,052	8,753,653
Counterparty and Cash Collateral, netting	(5,110)	(14,435)
Derivatives, at fair value, net	22,525	9,677
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	(9,683,062)	(6,941,097)
Counterparty and Cash Collateral, netting	5,110	14,875
Derivative, Total	(1,204)	(2,350)
Total	11,181,531	9,317,700
Total	0	440
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	4,864	1,785
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	0	0
Derivatives	0	0
Total	4,864	1,785
Fair Value, Measurements, Recurring | Level 2
Assets:
Non-Agency RMBS, at fair value	0	0
Agency MBS, at fair value	4,354,872	4,167,754
Loans held for investment, at fair value	0	0
Derivatives	22,771	22,327
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	0	0
Derivatives	(6,314)	(17,225)
Total	4,371,329	4,172,856
Fair Value, Measurements, Recurring | Level 3
Assets:
Non-Agency RMBS, at fair value	2,950,348	3,330,063
Agency MBS, at fair value	0	0
Loans held for investment, at fair value	13,538,052	8,753,653
Derivatives	0	0
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	(9,683,062)	(6,941,097)
Derivatives	0	0
Total	$ 6,805,338	$ 5,142,619
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	$ 17,000	$ 16,000
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	6,000	50,000
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	21,000	123,000
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	380,000	1,600,000
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	38,000	107,000
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	$ 386,000	$ 1,550,000

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		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Assets:
Loans held for investment,Unpaid Principal/Notional	$ 13,327,252	$ 9,030,908	$ 13,327,252	$ 9,030,908
Loans held for investment, at fair value	13,538,052	8,909,037	13,538,052	8,909,037	$ 8,753,653
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment, Unpaid Principal/Notional	9,622,994	7,334,475	9,622,994	7,334,475
Securitized debt at fair value, collateralized by loans held for investment, fair value	9,683,062	7,191,462	9,683,062	7,191,462	$ 6,941,097
Non-agency RMBS | Subordinated
Assets:
Fair Value	14,761	20,671	14,761	20,671
Gain (Loss) on Change in Fair Value	2,678	8,257	1,791	7,551
Non-agency RMBS | Senior, interest-only
Assets:
Principal or Notional Value	4,948,265	5,733,457	4,948,265	5,733,457
Fair Value	212,662	291,526	212,662	291,526
Gain (Loss) on Change in Fair Value	1,784	2,214	(16,446)	22,332
Non-agency RMBS | Subordinated, interest-only
Assets:
Principal or Notional Value	256,286	269,868	256,286	269,868
Fair Value	11,588	13,498	11,588	13,498
Gain (Loss) on Change in Fair Value	1,048	1,289	475	3,288
Agency MBS | Residential Pass-through
Assets:
Principal or Notional Value	586,030	0	586,030	0
Fair Value	614,758	0	614,758	0
Gain (Loss) on Change in Fair Value	(2,457)	0	(2,457)	0
Agency MBS | Commercial Pass-through
Assets:
Principal or Notional Value	407,943	0	407,943	0
Fair Value	410,013	0	410,013	0
Gain (Loss) on Change in Fair Value	(1,852)	0	(1,852)	0
Agency MBS | Interest-only
Assets:
Principal or Notional Value	3,176,110	3,474,731	3,176,110	3,474,731
Fair Value	114,810	157,088	114,810	157,088
Gain (Loss) on Change in Fair Value	(779)	(345)	831	430
Loans held for investment
Assets:
Gain (Loss) on Change in Fair Value	57,114	68,508	271,824	113,646
Securitized debt
Assets:
Gain (Loss) on Change in Fair Value	$ (38,494)	$ (46,923)	$ (95,120)	$ (67,029)

Fair Value Measurements - Inter

Fair Value Measurements - Interest Only MBS (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-Agency RMBS, at fair value		$ 2,950,348		$ 2,950,348		$ 3,330,063
Agency MBS, at fair value		4,354,872		4,354,872		4,167,754
Interest income	[1]	296,813	$ 250,953	836,801	$ 673,246
Interest-only | Residential Mortgage-Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest income		7,000	$ 10,000	24,000	$ 32,000
Interest-only | Residential Mortgage-Backed Securities | Non-Agency RMBS - Interest-only
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-Agency RMBS, at fair value		224,000		224,000		266,000
Interest-only | Residential Mortgage-Backed Securities | Agency MBS - Interest-only
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Agency MBS, at fair value		115,000		115,000		145,000
Non-Agency RMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-Agency RMBS, at fair value		$ 15,000		$ 15,000		$ 19,000
[1]	Includes interest income of consolidated VIEs of $241,195 and $195,488 for the quarters ended September 30, 2017 and 2016, respectively and interest income of consolidated VIEs of $668,621 and $488,353 for the nine months ended September 30, 2017 and 2016 respectively. See Note 8 to consolidated financial statements for further discussion.

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Input Reconciliation (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 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	(48,014)	(122)
Net unrealized gains (losses) included in income	(95,120)	(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	(4,159,073)	(4,797,255)
Securitized Debt, Principal payments	1,319,120	1,059,854
Securitized Debt, Sales and Settlements	245,369	608,816
Securitized Debt, Accretion (amortization) of purchase discounts	(4,247)	(2,128)
Securitized Debt, Gains (losses) included in other comprehensive income	0	0
Securitized Debt, Ending balance, Level 3	(9,683,062)	(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	71,116	257,914
Principal payments	(459,854)	(532,696)
Sales and settlements	(68,164)	(149,938)
Accretion (amortization) of purchase discounts	92,201	120,638
Other than temporary credit impairment losses	(41,702)	(57,986)
Realized gains (losses) on sales and settlements	12,031	13,761
Net unrealized gains (losses) included in income	(14,179)	3,173
Total unrealized gains (losses) for the period	22,724	(644)
Ending balance Level 3 assets	2,950,348	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	5,835,799	4,897,370
Principal payments	(1,298,856)	(1,022,414)
Sales and settlements	2,942	5,007
Accretion (amortization) of purchase discounts	(27,310)	(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	271,824	146,637
Total unrealized gains (losses) for the period	0	0
Ending balance Level 3 assets	$ 13,538,052	$ 8,753,653

Fair Value Measurements - Uno62

Fair Value Measurements - Unobservable Input Reconciliation - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 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 - Uno63

Fair Value Measurements - Unobservable Inputs Assumptions - Non-Agency RMBS Held for Investment (Detail) - Level 3	Sep. 30, 2017	Dec. 31, 2016
Non-Agency RMBS - Senior
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	4.60%	5.40%
Non-Agency RMBS - Senior interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	11.80%	12.50%
Non-Agency RMBS - Subordinated
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	5.90%	6.20%
Non-Agency RMBS - Subordinated interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average Discount Rate	10.90%	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	4.00%	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	10.00%	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	60.00%	22.00%
Loss Severity	95.00%	95.00%
Maximum | Non-Agency RMBS - Senior interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	28.00%	30.00%
CDR	64.00%	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	21.00%	18.00%
Loss Severity	77.00%	79.00%
Maximum | Non-Agency RMBS - Subordinated interest-only
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CPR	18.00%	15.00%
CDR	11.00%	11.00%
Loss Severity	59.00%	76.00%

Fair Value Measurements - Uno64

Fair Value Measurements - Unobservable Inputs Assumptions - Securitized Debt (Detail)	Sep. 30, 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	1.00%	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	22.00%	35.00%
Securitized debt at fair value, collateralized by loans held for investment, CDR Range	30.00%	30.00%
Securitized debt at fair value, collateralized by loans held for investment, Loss Severity Range	70.00%	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	4.14%	3.99%

Fair Value Measurements - Uno65

Fair Value Measurements - Unobservable Inputs Assumptions - Loans Held for Investment (Detail) - Loans Held for Investment at Fair Value - Level 3	Sep. 30, 2017	Dec. 31, 2016
Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Coupon	7.00%	7.10%
FICO	626	621
Loan-to-value (LTV)	88.00%	88.00%
Weighted Average | Single family
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	86.00%	86.00%
Weighted Average | Manufactured housing
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	5.00%	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	94.00%	97.00%
Weighted Average | Investor
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	2.00%	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	4.70%	5.20%
FICO	634	632
Loan-to-value (LTV)	89.00%	87.00%

Fair Value Measurements - Carry

Fair Value Measurements - Carrying and Fair Values (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securitized debt, collateralized by Non-Agency RMBS	$ 233,113	$ 334,124
Carrying Amount | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Repurchase agreements	6,709,821	5,600,903
Carrying Amount | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securitized debt, collateralized by Non-Agency RMBS	233,113	334,124
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Repurchase agreements	6,727,850	5,619,385
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securitized debt, collateralized by Non-Agency RMBS	$ 221,567	$ 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	Sep. 30, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	$ 6,709,821	$ 5,600,903
Repurchase Agreements | Agency MBS - Residential
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	3,096,233	3,087,734
Average balance of Repurchase agreements secured by:	$ 3,129,569	$ 4,159,651
Average borrowing rate of Repurchase agreements secured by:	1.39%	0.90%
Average remaining maturity of Repurchase agreements secured by:	21 days	32 days
Average original maturity of Repurchase agreements secured by:	76 days	112 days
MBS pledged as collateral at fair value on Repurchase agreements:	$ 3,332,640	$ 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:	3,613,588	2,513,169
Average balance of Repurchase agreements secured by:	$ 2,983,319	$ 2,322,683
Average borrowing rate of Repurchase agreements secured by:	3.25%	3.05%
Average remaining maturity of Repurchase agreements secured by:	73 days	98 days
Average original maturity of Repurchase agreements secured by:	109 days	155 days
MBS pledged as collateral at fair value on Repurchase agreements:	$ 4,817,669	$ 3,699,621
Repurchase Agreements | Residential Mortgage-Backed Securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding secured by:	6,709,821	5,600,903
Average balance of Repurchase agreements secured by:	6,112,888	6,482,334
MBS pledged as collateral at fair value on Repurchase agreements:	$ 8,150,309	$ 7,033,866

Repurchase Agreements - Maturit

Repurchase Agreements - Maturities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	$ 6,709,821	$ 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	3,777,160	2,947,604
30 to 59 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	1,591,370	958,956
60 to 89 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	330,186	407,625
90 to 119 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	28,798	559,533
Greater than or equal to 120 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements outstanding	$ 982,307	$ 727,185

Repurchase Agreements - Narrati

Repurchase Agreements - Narrative (Detail) - Repurchase Agreements - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Credit Suisse First Boston
Short-term Debt [Line Items]
Amount at risk	$ 404	$ 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	11.00%
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	77 days	104 days

Securitized Debt - Narrative (D

Securitized Debt - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Gains (losses) on extinguishment of debt	$ (1)		$ (45)		$ (48,016)	$ (1,811)
Securitized Loans | Non-agency MBS
Debt Instrument [Line Items]
Acquired securitized debt collateral outstanding principal balance	166		4,000
Repurchase of securitized debt borrowings, collateralized by Non-Agency RMBS	167		4,000
Gains (losses) on extinguishment of debt	(1)		$ (45)		(1)	(45)
Securitized Loans | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure | Non-agency MBS
Debt Instrument [Line Items]
Principal balance of debt	$ 247,000				$ 247,000		$ 350,000
Weighted average cost of financing	5.88%				5.88%		5.21%
Securitized Loans | Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure | Loans held for investment
Debt Instrument [Line Items]
Principal balance of debt	$ 9,600,000				$ 9,600,000		$ 7,100,000
Weighted average cost of financing	4.14%				4.14%		3.99%
Securitized Loans | Variable Interest Entities, Primary Beneficiary | Loans held for investment
Debt Instrument [Line Items]
Acquired securitized debt collateral outstanding principal balance		$ 197,000		$ 44,000
Repurchase of securitized debt borrowings, collateralized by Non-Agency RMBS		$ 245,000		$ 46,000
Gains (losses) on extinguishment of debt					$ (48,000)	$ (2,000)

Securitized Debt - Maturities (

Securitized Debt - Maturities (Detail) - Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure - Securitized Loans - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Non-agency MBS
Debt Instrument [Line Items]
Within One Year	$ 62,165	$ 98,565
One to Three Years	50,055	82,563
Three to Five Years	21,013	23,854
Greater Than Five Years	5,913	31,973
Total	139,146	236,955
Loans held for investment
Debt Instrument [Line Items]
Within One Year	1,856,397	1,151,519
One to Three Years	2,907,977	1,841,808
Three to Five Years	2,163,866	1,423,706
Greater Than Five Years	2,630,039	2,477,123
Total	$ 9,558,279	$ 6,894,156

Securitized Debt - Callable Deb

Securitized Debt - Callable Debt (Detail) - Securitized Loans $ in Thousands	Sep. 30, 2017USD ($)
Debt Instrument, Redemption [Line Items]
2,017	$ 811,395
2,018	1,002,614
2,019	416,722
2,020	4,232,520
2,021	2,961,293
Total	$ 9,424,544

Consolidated Securitization V73

Consolidated Securitization Vehicles and Other Variable Interest Entities - Narrative (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 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)	51,000	51,000
Variable Interest Entities, Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Assets	14,846,980	10,761,954
Liabilities	9,954,437	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	5,300,000
Subsidiaries | Subprime | Residential Mortgage
Variable Interest Entity [Line Items]
Mortgage loans	$ 550,000

Consolidated Securitization V74

Consolidated Securitization Vehicles and Other Variable Interest Entities - Effect on Consolidated Financial Condition (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Assets:
Non-Agency RMBS, at fair value	$ 2,950,348	$ 3,330,063
Loans held for investment, at fair value	13,538,052	8,753,653	$ 8,909,037
Accrued interest receivable	99,421	79,697
Other Assets	172,876	166,350
Liabilities:
Securitized debt, collateralized by Non-Agency RMBS	233,113	334,124
Securitized debt at fair value, collateralized by loans held for investment	9,683,062	6,941,097	$ 7,191,462
Accrued interest payable	64,280	48,670
Other liabilities	21,331	16,694
Variable Interest Entities, Primary Beneficiary
Assets:
Non-Agency RMBS, at fair value	1,646,762	1,842,080
Loans held for investment, at fair value	13,011,319	8,753,653
Accrued interest receivable	76,327	57,153
Other Assets	112,572	109,068
Liabilities:
Securitized debt, collateralized by Non-Agency RMBS	233,113	334,124
Securitized debt at fair value, collateralized by loans held for investment	9,683,062	6,941,097
Accrued interest payable	34,650	24,942
Other liabilities	3,612	$ 2,742
Consolidated Trusts | Variable Interest Entities, Primary Beneficiary
Assets:
Loans held for investment, at fair value	5,353,955
Other Assets	36,795
Liabilities:
Securitized debt at fair value, collateralized by loans held for investment	$ 4,171,458

Consolidated Securitization V75

Consolidated Securitization Vehicles and Other Variable Interest Entities - Effect on Consolidated Results (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Variable Interest Entity [Line Items]
Net interest income	$ 156,455	$ 156,042	$ 448,257	$ 432,126
Total other-than-temporary impairment losses	(784)	(993)	(4,245)	(8,555)
Portion of loss recognized in other comprehensive income (loss)	(10,684)	(10,581)	(39,431)	(34,652)
Net other-than-temporary credit impairment losses	(11,468)	(11,574)	(43,676)	(43,207)
Servicing fees	10,715	9,788	31,193	23,139
Variable Interest Entities, Primary Beneficiary
Variable Interest Entity [Line Items]
Total other-than-temporary impairment losses	(668)	(21)	(1,777)	(866)
Portion of loss recognized in other comprehensive income (loss)	(10,108)	(4,599)	(35,720)	(31,925)
Net other-than-temporary credit impairment losses	(10,776)	(4,620)	(37,497)	(32,791)
Servicing fees	10,492	9,788	30,970	23,139
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	241,195	195,488	668,621	488,353
Interest expense, Non-recourse liabilities of VIEs	101,856	70,715	290,264	168,738
Net interest income	$ 139,339	$ 124,773	$ 378,357	$ 319,615

Derivative Instruments - Effect

Derivative Instruments - Effect on Consolidated Financial Condition (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	$ 4,475,100,000	$ 2,640,600,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	22,525,000	9,677,000
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	(1,204,000)	(2,350,000)
Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	3,373,400,000	1,396,900,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	15,254,000	0
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	0	0
Swaptions
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding	482,000,000	624,000,000
Derivative Assets, Net Estimated Fair Value/Carrying Value	2,407,000	7,892,000
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	(1,204,000)	(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	4,864,000	1,785,000
Derivative Liabilities, Net Estimated Fair Value/Carrying Value	$ 0	$ 0

Derivative Instruments - Effe77

Derivative Instruments - Effect on Consolidated Results (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives	$ 9,204	$ 27,628	$ 19,902	$ (51,382)
Net gains (losses) on derivatives	1,363	13,360	(24,921)	(170,932)
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives	5,001	13,395	15,694	(36,840)
Net realized gains (losses) on derivatives	(3,491)	(4,595)	(27,222)	(84,571)
Treasury Futures
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives	3,467	12,149	3,079	(4,259)
Net realized gains (losses) on derivatives	(3,267)	(7,823)	(12,268)	(28,797)
Swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives	736	2,084	1,129	(10,283)
Net realized gains (losses) on derivatives	(1,083)	(1,850)	(5,333)	(5,615)
Other Derivative Assets
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains (losses) on derivatives	0	0	0	0
Net realized gains (losses) on derivatives	$ 0	$ 0	$ 0	$ (567)

Derivative Instruments - Effe78

Derivative Instruments - Effect on Consolidated Results - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Realized gains (losses) on terminations of interest rate swaps	$ 0	$ 0	$ (16,143)	$ (60,616)

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Realized losses on terminations of interest rate swaps	$ 0	$ 0	$ 16,143,000	$ 60,616,000
Derivative instruments terminated			$ 250,000,000
The weighted average pay rate on the Company's interest rate swaps	1.71%		1.71%		2.13%
The weighted average receive rate on the Company's interest rate swaps	1.39%		1.39%		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	$ 6,000,000		$ 6,000,000
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		9 Months Ended		12 Months Ended
	Feb. 28, 2017	Oct. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Preferred Stock, shares authorized (shares)			100,000,000		100,000,000		100,000,000
Preferred Stock, par value (usd per share)			$ 0.01		$ 0.01		$ 0.01
Issuance of preferred stock cost					$ 314,429
Dividends on preferred stock			$ 9,400	$ 0	$ 24,083	$ 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			$ 7,000		$ 15,000
Preferred stock dividends declared (in USD per share)			$ 0.50		$ 1.18
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			$ 3,000		$ 9,000
Preferred stock dividends declared (in USD per share)			$ 0.50		$ 1.50
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
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 ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Stock repurchase program, authorized amount	$ 350,000,000		$ 350,000,000
Number of shares repurchased (shares)	0		0
Stock repurchase program, remaining authorized repurchase amount	$ 100,000,000		$ 100,000,000
Dividends declared per share of common stock (usd per share)	$ 0.5	$ 0.48	$ 1.5	$ 1.94
Common dividends declared			$ 282,275,000	$ 364,717,000
Regular Dividend
Class of Stock [Line Items]
Dividends declared per share of common stock (usd per share)	$ 0.50	$ 0.48	$ 1.50	$ 1.44
Common dividends declared	$ 94,000,000	$ 91,000,000	$ 282,000,000	$ 271,000,000
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

Capital Stock - Earnings Per Sh

Capital Stock - Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator:
Net income available to common shareholders	$ 129,832	$ 172,817	$ 392,977	$ 330,042
Effect of dilutive securities:	0	0	0	0
Dilutive net income available to common shareholders	$ 129,832	$ 172,817	$ 392,977	$ 330,042
Denominator:
Weighted average basic shares (shares)	187,779,794	187,729,765	187,773,715	187,727,667
Effect of dilutive securities (shares)	412,317	190,027	403,042	190,027
Weighted average dilutive shares (shares)	188,192,111	187,919,792	188,176,757	187,917,694
Net income per average share attributable to common stockholders - Basic (usd per share)	$ 0.69	$ 0.92	$ 2.09	$ 1.76
Net income per average share attributable to common stockholders - Diluted (usd per share)	$ 0.69	$ 0.92	$ 2.09	$ 1.76

Accumulated Other Comprehensi83

Accumulated Other Comprehensive Income - Components of AOCI (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
AOCI [Roll Forward]
Beginning Balance	$ 3,123,533	$ 2,946,188
Ending Balance	3,646,431	3,036,800
Unrealized gains (losses) on available-for-sale securities, net
AOCI [Roll Forward]
Beginning Balance	718,106	773,791
OCI before reclassifications	59,114	94,059
Amounts reclassified from AOCI	35,898	29,853
Net current period OCI	95,012	123,912
Ending Balance	813,118	897,703
Total Accumulated OCI Balance
AOCI [Roll Forward]
Beginning Balance	718,106	773,791
OCI before reclassifications	59,114	94,059
Amounts reclassified from AOCI	35,898	29,853
Net current period OCI	95,012	123,912
Ending Balance	$ 813,118	$ 897,703

Accumulated Other Comprehensi84

Accumulated Other Comprehensive Income - Reclassifications from AOCI (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on sales of investments	$ 1	$ 3,079	$ 9,709	$ 7,035
Net other-than-temporary credit impairment losses	(11,468)	(11,574)	(43,676)	(43,207)
Income before income taxes	139,250	172,830	417,232	330,107
Income taxes	(18)	(13)	(172)	(65)	$ 0
Net income (loss)	$ 139,232	$ 172,817	417,060	330,042
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			7,778	13,354
Net other-than-temporary credit impairment losses			(43,676)	(43,207)
Income before income taxes			(35,898)	(29,853)
Income taxes			0	0
Net income (loss)			$ (35,898)	$ (29,853)

Equity Compensation, Employme85

Equity Compensation, Employment Agreements and other Benefit Plans - Narrative (Detail) shares in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2017USD ($)shares	Mar. 31, 2017USD ($)shares	Sep. 30, 2016USD ($)	Mar. 31, 2016USD ($)shares	Sep. 30, 2017USD ($)installmentshares	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common dividends declared	$ 1,000,000		$ 620,000		$ 2,755,000	$ 1,375,000
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				6,000
Restricted Stock | Minimum | 2007 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					2 years
Restricted Stock | Maximum | 2007 Equity Incentive Plan
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		112		266
Grant date fair value		$ 2,000,000		$ 3,000,000
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		180	144		180
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%
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	$ 84,000		$ 78,000		$ 299,000	$ 292,000
401(k) Plan | Maximum
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%

Income Taxes Income Taxes (Deta

Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax expense	$ 18	$ 13	$ 172	$ 65	$ 0

Credit Risk and Interest Rate87

Credit Risk and Interest Rate Risk - Offsetting Assets and Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Repurchase Agreements
Gross Amounts of Recognized Assets (Liabilities)	$ (6,709,821)	$ (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	(6,709,821)	(5,600,903)
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	8,150,308	7,033,866
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	1,986	2,545
Net Amount	1,442,473	1,435,508
Derivative Asset
Net Amounts Offset in the Consolidated Statements of Financial Position	22,525	9,677
Derivative Liability
Net Amounts Offset in the Consolidated Statements of Financial Position	(1,204)	(2,350)
Total Liabilities
Gross Amounts of Recognized Assets (Liabilities)	(6,688,500)	(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	(6,688,500)	(5,593,576)
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	8,151,587	7,044,207
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Cash Collateral (Received) Pledged	49,322	45,492
Net Amount	1,512,409	1,496,123
Interest Rate Swaps
Derivative Asset
Gross Amounts of Recognized Assets (Liabilities)	20,364	14,435
Gross Amounts Offset in the Consolidated Statements of Financial Position	(5,110)	(14,435)
Net Amounts Offset in the Consolidated Statements of Financial Position	15,254	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	46,339	0
Net Amount	61,593	0
Derivative Liability
Gross Amounts of Recognized Assets (Liabilities)	(5,110)	(14,875)
Gross Amounts Offset in the Consolidated Statements of Financial Position	5,110	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)	4,864	1,785
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	4,864	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	997	3,320
Net Amount	5,861	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)	2,407	7,892
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	2,407	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	2,407	7,892
Derivative Liability
Gross Amounts of Recognized Assets (Liabilities)	(1,204)	(2,350)
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	(1,204)	(2,350)
Gross Amounts Not Offset with Financial Assets (Liabilities) in the Consolidated Statements of Financial Position, Financial Instruments	1,279	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	$ 75	$ 7,991

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	Oct. 01, 2017	Sep. 30, 2017	Sep. 30, 2016
Subsequent Event [Line Items]
Repayments of securitized debt		$ 1,564,489	$ 773,875
Securitized Loans | Subsequent Event
Subsequent Event [Line Items]
Repayments of securitized debt	$ 811,000