Summary of the Significant Accounting Policies	3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]
Summary of the Significant Accounting Policies	Summary of the Significant Accounting Policies (a) Basis of Presentation and Consolidation The accompanying consolidated financial statements and related notes of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). In the opinion of management, all adjustments considered necessary for a fair presentation of the Company's financial position, results of operations and cash flows have been included. Certain prior period amounts have been reclassified to conform to the current period's presentation. The consolidated financial statements include, the Company’s accounts, the accounts of its wholly-owned subsidiaries, and variable interest entities (“VIEs”) in which the Company is the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation. The Company uses securitization trusts considered to be VIEs in its securitization and re-securitization transactions. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest, or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary, and is generally the entity with (i) the power to direct the activities that most significantly impact the VIEs’ economic performance, and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. For VIEs that do not have substantial on-going activities, the power to direct the activities that most significantly impact the VIEs’ economic performance may be determined by an entity’s involvement with the design and structure of the VIE. The trusts are structured as pass through entities that receive principal and interest on the underlying collateral and distribute those payments to the security holders. The assets held by the securitization entities are restricted in that they can only be used to fulfill the obligations of the securitization entity. The Company’s risks associated with its involvement with these VIEs are limited to its risks and rights as a holder of the security it has retained. Determining the primary beneficiary of a VIE requires judgment. The Company determined that for the securitizations it consolidates, its ownership provides the Company with the obligation to absorb losses or the right to receive benefits from the VIE that could be significant to the VIE. In addition, the Company has the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance (“power”) such as rights to direct servicer activity or the Company was determined to have power in connection with its involvement with the structure and design of the VIE. The Company’s interest in the assets held by these securitization vehicles, which are consolidated on the Company’s Statements of Financial Condition, is restricted by the structural provisions of these trusts, and a recovery of the Company’s investment in the vehicles will be limited by each entity’s distribution provisions. The liabilities of the securitization vehicles, which are also consolidated on the Company’s Statements of Financial Condition, are non-recourse to the Company, and can only be satisfied from each securitization vehicle’s respective asset pool. The assets of securitization entities are comprised of residential mortgage backed securities (“RMBS”) or residential mortgage loans. See Notes 3, 4 and 8 for further discussion of the characteristics of the securities and loans in the Company’s portfolio. (b) Statements of Financial Condition Presentation The Company’s Consolidated Statements of Financial Condition include both the Company’s direct assets and liabilities and the assets and liabilities of consolidated securitization vehicles. Assets of each consolidated VIE can only be used to satisfy the obligations of that VIE, and the liabilities of consolidated VIEs are non-recourse to the Company. The Company is not obligated to provide, nor does it intend to provide, any financial support to these consolidated securitization vehicles. The notes to the consolidated financial statements describe the Company’s assets and liabilities including the assets and liabilities of consolidated securitization vehicles. See Note 8 for additional information related to the Company’s investments in consolidated securitization vehicles. (c) 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, 2017, 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 March 31, 2018 or December 31, 2017. Fair Value Disclosure A complete discussion of the methodology utilized by the Company to estimate the fair value of its financial instruments is included in Note 5 to these consolidated financial statements. (e) Recent Accounting Pronouncements Income Statement - Reporting Comprehensive Income - (Topic 220) In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Cuts and Jobs Act and will improve the usefulness of information reported to financial statement users. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The amendments in this Update also require certain disclosures about stranded tax effects. 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. 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 Company has adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a significant impact on the Company's consolidated financial statements. Statement of Cash Flows - Restricted Cash - (Topic 230) In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows - Restricted Cash. This update requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update do not provide a definition of restricted cash or restricted cash equivalents. The Company has adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a significant impact on the Company's consolidated financial statements. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments - (Topic 230) In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments. This update provides guidance on eight specific cash flow issues. The guidance is intended to reduce diversity in practice on those issues across all industries. The Company has adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a significant impact on the Company's consolidated Statements of Cash Flows. Financial Instruments - Credit Losses - (Topic 326) In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. This update replaces the current model for recognizing credit losses from an incurred credit loss model to a current expected credit loss (CECL) model for instruments measured at amortized cost and requires entities to record allowances for available-for-sale (AFS) debt securities when the fair value of an AFS debt security is below the amortized cost of the asset rather than reduce the carrying amount, as the Company does under the current OTTI model. This update also simplifies the accounting model for purchased credit-impaired debt securities and loans. The changes in the allowances created in accordance with this update will be recorded in earnings. The update also expands the disclosure requirements regarding the Company's assumptions, models, and methods for estimating the expected credit losses. In addition, the Company will disclose the amortized cost balance for each class of financial asset by credit quality indicator, disaggregated by the year of origination. The guidance in the ASU is effective for the Company as of January 1, 2020. Early adoption is allowed, beginning January 1, 2019. The standard requires entities to record a cumulative-effect adjustment to the statement of financial position as of the beginning of the first reporting period in which the guidance is effective. The Company is currently evaluating what impact this update will have on the consolidated financial statements. 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 Company has adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a significant impact on the Company's consolidated financial statements.

Summary of the Significant Accounting Policies

(a) Basis of Presentation and Consolidation

The accompanying consolidated financial statements and related notes of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). In the opinion of management, all adjustments considered necessary for a fair presentation of the Company's financial position, results of operations and cash flows have been included. Certain prior period amounts have been reclassified to conform to the current period's presentation.

The consolidated financial statements include, the Company’s accounts, the accounts of its wholly-owned subsidiaries, and variable interest entities (“VIEs”) in which the Company is the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation.

The Company uses securitization trusts considered to be VIEs in its securitization and re-securitization transactions. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest, or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary, and is generally the entity with (i) the power to direct the activities that most significantly impact the VIEs’ economic performance, and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. For VIEs that do not have substantial on-going activities, the power to direct the activities that most significantly impact the VIEs’ economic performance may be determined by an entity’s involvement with the design and structure of the VIE.

The trusts are structured as pass through entities that receive principal and interest on the underlying collateral and distribute those payments to the security holders. The assets held by the securitization entities are restricted in that they can only be used to fulfill the obligations of the securitization entity. The Company’s risks associated with its involvement with these VIEs are limited to its risks and rights as a holder of the security it has retained.

Determining the primary beneficiary of a VIE requires judgment. The Company determined that for the securitizations it consolidates, its ownership provides the Company with the obligation to absorb losses or the right to receive benefits from the VIE that could be significant to the VIE. In addition, the Company has the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance (“power”) such as rights to direct servicer activity or the Company was determined to have power in connection with its involvement with the structure and design of the VIE.

The Company’s interest in the assets held by these securitization vehicles, which are consolidated on the Company’s Statements of Financial Condition, is restricted by the structural provisions of these trusts, and a recovery of the Company’s investment in the vehicles will be limited by each entity’s distribution provisions. The liabilities of the securitization vehicles, which are also consolidated on the Company’s Statements of Financial Condition, are non-recourse to the Company, and can only be satisfied from each securitization vehicle’s respective asset pool.

The assets of securitization entities are comprised of residential mortgage backed securities (“RMBS”) or residential mortgage loans. See Notes 3, 4 and 8 for further discussion of the characteristics of the securities and loans in the Company’s portfolio.

(b) Statements of Financial Condition Presentation

The Company’s Consolidated Statements of Financial Condition include both the Company’s direct assets and liabilities and the assets and liabilities of consolidated securitization vehicles. Assets of each consolidated VIE can only be used to satisfy the obligations of that VIE, and the liabilities of consolidated VIEs are non-recourse to the Company. The Company is not obligated to provide, nor does it intend to provide, any financial support to these consolidated securitization vehicles. The notes to the consolidated financial statements describe the Company’s assets and liabilities including the assets and liabilities of consolidated securitization vehicles. See Note 8 for additional information related to the Company’s investments in consolidated securitization vehicles.

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, 2017, 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 March 31, 2018 or December 31, 2017.

Fair Value Disclosure

A complete discussion of the methodology utilized by the Company to estimate the fair value of its financial instruments is included in Note 5 to these consolidated financial statements.

(e) Recent Accounting Pronouncements

Income Statement - Reporting Comprehensive Income - (Topic 220)

In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Cuts and Jobs Act and will improve the usefulness of information reported to financial statement users. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The amendments in this Update also require certain disclosures about stranded tax effects. 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.

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 Company has adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a

significant impact on the Company's consolidated financial statements.

Statement of Cash Flows - Restricted Cash - (Topic 230)

In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows - Restricted Cash. This update requires that a

statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally

described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and

restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and

end-of-period total amounts shown on the statement of cash flows. The amendments in this Update do not provide a definition

of restricted cash or restricted cash equivalents. The Company has adopted this guidance as of January 1, 2018. The adoption of

this guidance did not have a significant impact on the Company's consolidated financial statements.

Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments - (Topic 230)

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows - Classification of Certain Cash Receipts and

Cash Payments. This update provides guidance on eight specific cash flow issues. The guidance is intended to reduce diversity

in practice on those issues across all industries. The Company has adopted this guidance as of January 1, 2018. The adoption of

this guidance did not have a significant impact on the Company's consolidated Statements of Cash Flows.

Financial Instruments - Credit Losses - (Topic 326)

In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. This update replaces the current model for recognizing credit losses from an incurred credit loss model to a current expected credit loss (CECL) model for instruments measured at amortized cost and requires entities to record allowances for available-for-sale (AFS) debt securities when the fair value of an AFS debt security is below the amortized cost of the asset rather than reduce the carrying amount, as the Company does under the current OTTI model. This update also simplifies the accounting model for purchased credit-impaired debt securities and loans. The changes in the allowances created in accordance with this update will be recorded in earnings. The update also expands the disclosure requirements regarding the Company's assumptions, models, and methods for estimating the expected credit losses. In addition, the Company will disclose the amortized cost balance for each class of financial asset by credit quality indicator, disaggregated by the year of origination. The guidance in the ASU is effective for the Company as of January 1, 2020. Early adoption is allowed, beginning January 1, 2019. The standard requires entities to record a cumulative-effect adjustment to the statement of financial position as of the beginning of the first reporting period in which the guidance is effective. The Company is currently evaluating what impact this update will have on the consolidated financial statements.

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 Company has adopted this guidance

as of January 1, 2018. The adoption of this guidance did not have a significant impact on the Company's consolidated financial

statements.