Javelin Mortgage Investment (JMI) 10-Q 4 Aug 14 2014 Q2 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	6 Months Ended
	Jun. 30, 2014	Aug. 01, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'JAVELIN MORTGAGE INVESTMENT CORP.	'
Entity Central Index Key	'0001552890	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	11,999,084

Condensed_Balance_Sheets_Unaud

Condensed Balance Sheets (Unaudited) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'		'
Cash	$22,397		$41,524
Cash collateral posted to counterparties	462		648
Agency Securities, available for sale, at fair value (including pledged securities of $1,180,339 and $770,172)	1,196,872		801,777
Non-Agency Securities, trading, at fair value (including pledged securities of $155,783 and $143,080)	155,783		143,399
Linked Transactions, net, at fair value (including pledged securities of $126,250 and $140,945)	14,448		16,322
Derivatives, at fair value	25,474	[1]	59,703	[1]
Accrued interest receivable	3,072		2,336
Prepaid and other assets	475		623
Total Assets	1,418,983		1,066,332
Liabilities:	'		'
Repurchase agreements	1,233,195		839,405
Cash collateral posted by counterparties	23,766		53,314
Accrued interest payable	819		611
Accounts payable and other accrued expenses	451		1,722
Total Liabilities	1,258,231		895,052
Commitments and Contingencies	'		'
Stockholders’ Equity:	'		'
Preferred stock, $0.001 par value, 25,000 shares authorized, none issued and outstanding at June 30, 2014 and December 31, 2013	0		0
Common stock, $0.001 par value, 250,000 shares authorized, 11,999 and 11,993 shares issued and outstanding at June 30, 2014 and December 31, 2013	12		12
Additional paid-in capital	244,038		243,951
Accumulated deficit	-90,974		-69,540
Accumulated other comprehensive income (loss)	7,676		-3,143
Total Stockholders’ Equity	160,752		171,280
Total Liabilities and Stockholders’ Equity	$1,418,983		$1,066,332
[1]	See Note 5, “Fair Value of Financial Instruments” for additional discussion.

Condensed_Balance_Sheets_Unaud1

Condensed Balance Sheets (Unaudited) (Parentheticals) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Preferred stock, par value (in usd per share)	$0.00	$0.00
Preferred stock, shares authorized (in Shares)	25,000,000	25,000,000
Preferred stock, shares issued (in Shares)	0	0
Preferred stock, shares outstanding (in Shares)	0	0
Common stock, par value (in Dollars per share)	$0.00	$0.00
Common stock, shares authorized (in Shares)	250,000,000	250,000,000
Common stock, shares issued (in Shares)	11,999,000	11,993,000
Common stock, shares outstanding (in Shares)	11,999,000	11,993,000
US Government Agencies Debt Securities	'	'
Plеdgеd assеts	$1,180,339	$770,172
Non-Agency Securities	'	'
Plеdgеd assеts	155,783	143,080
Linked Transactions	'	'
Plеdgеd assеts	$126,250	$140,945

Condensed_Statement_of_Operati

Condensed Statement of Operations (Unaudited) (USD $)	3 Months Ended				6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014	Jun. 30, 2013
Interest Income:	'		'		'	'
Agency Securities, net of amortization of premium	$8,031		$9,336		$16,476	$16,480
Non-Agency Securities, including discount accretion	2,410		1,832		4,712	3,692
Total Interest Income	10,441		11,168		21,188	20,172
Interest expense	-1,769		-1,924		-3,300	-3,651
Net interest income	8,672		9,244		17,888	16,521
Other Income (Loss):	'		'		'	'
Realized gain (loss) on sale of Agency Securities (reclassified from Other comprehensive income (loss))	-34		0		8,776	0
Gain (loss) on Non-Agency Securities	288		-5,635		1,121	-3,426
Realized loss on short sale of U.S. Treasury Securities	0		-390		0	-390
Unrealized net gain (loss) and net interest income (loss) from Linked Transactions	2,950		-2,288		7,460	-2,288
Unrealized loss on sale of U.S. Treasury Securities sold short	0		-2,716		0	-2,716
Subtotal	3,204		-11,029		17,357	-8,820
Realized loss on derivatives	-3,097	[1]	-1,989	[1]	-6,203	-2,939	[1]
Unrealized gain (loss) on derivatives	-15,703		43,181		-35,732	46,626
Subtotal	-18,800		41,192		-41,935	43,687
Total Other Income (Loss)	-15,596		30,163		-24,578	34,867
Expenses:	'		'		'	'
Management fee	915		790		1,828	1,352
Professional fees	422		138		1,164	333
Insurance	111		56		220	112
Board compensation	233		67		357	150
Other	171		119		380	226
Total expenses	1,852		1,170		3,949	2,173
Net income (loss) before taxes	-8,776		38,237		-10,639	49,215
Income tax expense	0		0		0	-2
Net Income (Loss)	-8,776		38,237		-10,639	49,213
Net Income (Loss) per common share (in usd per share)	($0.73)		$3.56		($0.89)	$5.39
Weighted average common shares outstanding (in shares)	11,996		10,731		11,928	9,124
Dividends	'		'		'	'
Common stock dividends declared	$5,398		$7,935		$10,795	$13,110
Common stock dividends declared per share (in usd per share)	$0.45		$0.69		$0.90	$1.38
Common shares of record-end of period (in shares)	11,999		13,500		11,999	13,500
[1]	Interest expense related to our interest rate swap contracts is recorded in realized loss on derivatives on the condensed consolidated statements of operations. For additional information, see Note 10 to the condensed consolidated financial statements.

Condensed_Statement_of_Compreh

Condensed Statement of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net Income (Loss)	($8,776)	$38,237	($10,639)	$49,213
Other comprehensive income (loss):	'	'	'	'
Reclassification adjustment for realized (gain) loss on sale of Agency Securities	34	0	-8,776	0
Net unrealized gain (loss) on available for sale Agency Securities	14,297	-77,461	19,595	-93,301
Other comprehensive income (loss)	14,331	-77,461	10,819	-93,301
Comprehensive Income (Loss)	$5,555	($39,224)	$180	($44,088)

Condensed_Statement_of_Stockho

Condensed Statement of Stockholders' Equity (Unaudited) (USD $)	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
In Thousands, unless otherwise specified
Balance at Dec. 31, 2013	$171,280	$12	$243,951	($69,540)	($3,143)
Balance (in Shares) at Dec. 31, 2013	'	11,993	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'
Common stock dividends declared	-10,795	'	'	-10,795	'
Stock based board compensation, net of withholding requirements	87	'	87	'	'
Stock based board compensation, net of withholding requirements (shares)	'	6	'	'	'
Net loss	-10,639	'	'	-10,639	'
Other comprehensive income	10,819	'	'	'	10,819
Balance at Jun. 30, 2014	$160,752	$12	$244,038	($90,974)	$7,676
Balance (in Shares) at Jun. 30, 2014	'	11,999	'	'	'

Condensed_Statements_of_Cash_F

Condensed Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash Flows From Operating Activities:	'	'
Net Income (Loss)	($10,639)	$49,213
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Realized gain on sale of Agency Securities	-8,776	0
(Gain) loss on Non-Agency Securities	-1,121	3,426
Unrealized net (gain) loss and net interest income from Linked Transactions	-7,460	2,288
Stock based Board compensation	87	0
Gain on short sale of U.S. Treasury Securities	0	390
Changes in operating assets and liabilities:	'	'
Increase in accrued interest receivable	-736	-2,264
(Increase) decrease in prepaid and other assets	148	-155
(Increase) decrease in derivatives, at fair value	34,229	-43,650
Increase in accrued interest payable	208	27
Increase (decrease) in accounts payable and other accrued expenses	-1,271	174
Net cash provided by operating activities	5,693	12,672
Cash Flows From Investing Activities:	'	'
Purchases of Agency Securities	-1,161,461	-858,581
Purchases of Non-Agency Securities	-12,020	-33,275
Cash receipts (disbursements) on Linked Transactions	3,369	-11,015
Principal repayments of Agency Securities	43,659	43,042
Principal repayments of Non-Agency Securities	7,048	10,246
Proceeds from sales of Agency Securities	740,952	0
Disbursements on reverse repurchase agreements	0	-1,008,393
Receipts from reverse repurchase agreements	0	771,375
Change in cash collateral, net	-29,362	-8,798
Net cash used in investing activities	-407,815	-1,095,399
Cash Flows From Financing Activities:	'	'
Issuance of common stock, net of expenses	0	113,217
Proceeds from repurchase agreements	4,059,645	5,207,875
Principal repayments on repurchase agreements	-3,665,855	-4,447,735
Common stock dividends paid	-10,795	-13,110
Net cash provided by financing activities	382,995	1,094,349
Net increase (decrease) in cash	-19,127	11,622
Cash - beginning of period	41,524	36,316
Cash - end of period	22,397	47,938
Supplemental Disclosure:	'	'
Cash paid during the period for interest	8,969	3,560
Non-Cash Investing and Financing Activities:	'	'
Unrealized gain (loss) on investment in available for sale Agency Securities	19,595	-93,301
Linked Transaction value of purchased Non-Agency Securities	5,965	0
Agency Securities	'	'
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Accretion (amortization) of discounts and premiums, investments	1,350	2,627
Non-Agency Securities	'	'
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Accretion (amortization) of discounts and premiums, investments	-326	596
Proceeds	'	'
Cash Flows From Financing Activities:	'	'
Proceeds from (Payments for) U.S. Treasury Securities	0	304,228
Payments	'	'
Cash Flows From Financing Activities:	'	'
Proceeds from (Payments for) U.S. Treasury Securities	$0	($70,126)

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X promulgated by the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of only normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the quarter and six months ended June 30, 2014 are not necessarily indicative of the results that may be expected for the calendar year ending December 31, 2014. These unaudited financial statements should be read in conjunction with the audited financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2013.
	The condensed consolidated financial statements include the accounts of JAVELIN Mortgage Investment Corp. and its subsidiary. All intercompany accounts and transactions have been eliminated. 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. Actual results could differ from those estimates. Significant estimates affecting the accompanying financial statements include the valuation of MBS (as defined below) and derivative instruments.

Organization_and_Nature_of_Bus

Organization and Nature of Business Operations	6 Months Ended
	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization and Nature of Business Operations	'
	Organization and Nature of Business Operations
	References to “we,” “us,” “our,” "JAVELIN" or the “Company” are to JAVELIN Mortgage Investment Corp. References to "ARRM" are to ARMOUR Residential Management LLC, a Delaware limited liability company.
	We are an externally managed Maryland corporation formed on June 18, 2012 and managed by ARRM, an investment advisor registered with the SEC (see Note 15, “Related Party Transactions” for additional discussion). We invest primarily in fixed rate and hybrid adjustable rate mortgage backed securities. Some of these securities are issued or guaranteed by a United States (“U.S.”) Government-sponsored entity (“GSE”), such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac), or guaranteed by the Government National Mortgage Administration (Ginnie Mae) (collectively, “Agency Securities”). Other securities backed by residential mortgages in which we invest, for which the payment of principal and interest is not guaranteed by a GSE or government agency (collectively, “Non-Agency Securities” and together with Agency Securities, “MBS”), may benefit from credit enhancement derived from structural elements such as subordination, over collateralization or insurance. We also may invest in collateralized commercial mortgage backed securities and other mortgage related investments, including mortgage loans, mortgage related derivatives and mortgage servicing rights. From time to time, a portion of our assets may be invested in unsecured notes and bonds issued by GSEs, U.S. Treasuries and money market instruments, subject to certain income tests we must satisfy for our qualification as a real estate investment trust (“REIT”). Our charter permits us to invest in Agency Securities and Non-Agency Securities.
	We have elected to be taxed as a REIT under the Internal Revenue Code (the “Code”). Our qualification as a REIT depends on our ability to meet, on a continuing basis, various complex requirements under the Code relating to, among other things, the sources of our gross income, the composition and values of our assets, our distribution levels and the concentration of ownership of our capital stock. We believe that we are organized in conformity with the requirements for qualification as a REIT under the Code and our manner of operations enables us to meet the requirements for taxation as a REIT for federal income tax purposes.
	As a REIT, we will generally not be subject to federal income tax on the taxable REIT income that we currently distribute to our stockholders. If we fail to qualify as a REIT in any taxable year and do not qualify for certain statutory relief provisions, we will be subject to federal income tax at regular corporate rates. Even if we qualify as a REIT for federal income tax purposes, we may still be subject to some federal, state and local taxes on our income.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Cash
	Cash includes cash on deposit with financial institutions. We may maintain deposits in federally insured financial institutions in excess of federally insured limits. However, management believes we are not exposed to significant credit risk due to the financial position and creditworthiness of the depository institutions in which those deposits are held.
	Cash Collateral Posted To/By Counterparties
	Cash collateral posted to/by counterparties represents cash posted by us to counterparties or posted by counterparties to us as collateral for our interest rate swap contracts (including swaptions) and repurchase agreements on our MBS.
	MBS, at Fair Value
	We generally intend to hold most of our MBS for extended periods of time. We may, from time to time, sell any of our MBS as part of the overall management of our MBS portfolio. Management determines the appropriate classifications of the securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date.
	Purchases and sales of our MBS are recorded on the trade date. However, if on the purchase settlement date, a repurchase agreement is used to finance the purchase of an MBS with the same counterparty and such transactions are determined to be linked, then the MBS and linked repurchase borrowing will be reported on the same settlement date as Linked Transactions (see below).
	Agency Securities
	At June 30, 2014 and December 31, 2013, all of our Agency Securities were classified as available for sale securities. Agency Securities classified as available for sale are reported at their estimated fair values with unrealized gains and losses excluded from earnings and reported as part of the condensed consolidated statements of comprehensive income (loss).
	We evaluate Agency Securities for other than temporary impairment at least on a quarterly basis and more frequently when economic or market concerns warrant such evaluation. We consider an impairment to be other than temporary if we (1) have the intent to sell the Agency Securities, (2) believe it is more likely than not that we will be required to sell the securities before recovery (for example, because of liquidity requirements or contractual obligations) or (3) a credit loss exists. Impairment losses recognized establish a new cost basis for the related Agency Securities.
	Non-Agency Securities
	At June 30, 2014 and December 31, 2013, all of our Non-Agency Securities were classified as trading securities. Non-Agency Securities classified as trading are reported at their estimated fair values with unrealized gains and losses included in other income (loss) as a component of the statements of operations. We estimate future cash flows for each Non-Agency Security and then discount those cash flows based on our estimates of current market yield for each individual security. We then compare our calculated price with our pricing services and/or dealer marks. Our estimates for future cash flows and current market yields incorporate such factors as coupons, prepayment speeds, defaults, delinquencies and severities.
	Accrued Interest Receivable and Payable
	Accrued interest receivable includes interest accrued between payment dates on MBS. Accrued interest payable includes interest payable on our repurchase agreements.
	Repurchase Agreements
	We finance the acquisition of our MBS through the use of repurchase agreements. Our repurchase agreements are secured by our MBS and bear interest rates that have historically moved in close relationship to the Federal Funds Rate and the London Interbank Offered Rate (“LIBOR”). Under these repurchase agreements, we sell MBS to a lender and agree to repurchase the same MBS in the future for a price that is higher than the original sales price. The difference between the sales price that we receive and the repurchase price that we pay represents interest paid to the lender. A repurchase agreement operates as a financing arrangement (with the exception of repurchase agreements accounted for as a component of a Linked Transaction described below) under which we pledge our MBS as collateral to secure a loan which is equal in value to a specified percentage of the estimated fair value of the pledged collateral. We retain beneficial ownership of the pledged collateral. At the maturity of a repurchase agreement, we are required to repay the loan and concurrently receive back our pledged collateral from the lender or, with the consent of the lender, we may renew such agreement at the then prevailing interest rate. The repurchase agreements may require us to pledge additional assets to the lender in the event the estimated fair value of the existing pledged collateral declines.
	In addition to the repurchase agreement financing discussed above, we may enter into reverse repurchase agreements with certain of our repurchase agreement counterparties. Under a typical reverse repurchase agreement, we purchase U.S. Treasury Securities from a borrower in exchange for cash and agree to sell the same securities in the future in exchange for a price that is higher than the original purchase price. The difference between the purchase price originally paid and the sale price represents interest received from the borrower. Reverse repurchase agreement receivables and repurchase agreement liabilities are presented net when they meet certain criteria, including being with the same counterparty, being governed by the same master repurchase agreement ("MRA"), settlement through the same brokerage or clearing account and maturing on the same day. We did not have any reverse repurchase agreements outstanding at June 30, 2014 or December 31, 2013.
	Obligations to Return Securities Received as Collateral, at Fair Value
	At certain times, we also sell to third parties the U.S. Treasury Securities received as collateral for reverse repurchase agreements and recognize the resulting obligation to return said U.S. Treasury Securities as a liability on our condensed consolidated balance sheets. Interest is recorded on the repurchase agreements, reverse repurchase agreements and U.S. Treasury Securities sold short on an accrual basis and presented as net interest expense. Both parties to the transaction have the right to make daily margin calls based on changes in the fair value of the collateral received and/or pledged. We did not have any obligations to return securities received as collateral at June 30, 2014 or December 31, 2013.
	Derivatives, at Fair Value
	We recognize all derivatives as either assets or liabilities at fair value on our condensed consolidated balance sheets. All changes in the fair values of our derivatives are reflected in our condensed consolidated statements of operations. We designate derivatives as hedges for tax purposes and any unrealized derivative gains or losses do not affect our distributable net taxable income.
	Linked Transactions
	The initial purchase of Non-Agency Securities and the related contemporaneous repurchase financing of such MBS with the same counterparty are considered part of the same arrangement, or a “Linked Transaction,” when certain criteria are met. Our acquisition of a Non-Agency Security and a related repurchase financing provided by the seller are generally considered to be linked if the initial transfer of and repurchase financing are contractually contingent, or there is a limited secondary market for the purchased security. The components of a Linked Transaction are evaluated on a combined basis and in totality, accounted for as a forward contract and reported as “Linked Transactions” on our balance sheets. Changes in the fair value of the Non-Agency Securities and repurchase liabilities underlying the Linked Transactions and associated interest income and expense are reported as “unrealized net gains and net interest income from Linked Transactions” on our statements of operations and are not included in other comprehensive loss. When the linking criteria are no longer met, the initial transfer (i.e., the purchase of a security) and repurchase financing will no longer be treated as a Linked Transaction and will be evaluated and reported separately as a MBS purchase and repurchase financing.
	Preferred Stock
	At June 30, 2014, we were authorized to issue up to 25,000 shares of preferred stock, par value $0.001 per share, with such designations, voting and other rights and preferences as may be determined from time to time by our Board of Directors ("Board") or a committee thereof. We have not issued any preferred stock to date.
	Common Stock
	At June 30, 2014, we were authorized to issue up to 250,000 shares of common stock, par value $0.001 per share, with such designations, voting and other rights and preferences as may be determined from time to time by our Board. We had 11,999 shares of common stock issued and outstanding at June 30, 2014 and 11,993 shares of common stock issued and outstanding at December 31, 2013.
	Common Stock Repurchased
	On October 30, 2013, we announced that our Board had authorized a stock repurchase program of up to 2,000 shares of our common stock outstanding (the “Repurchase Program”). On March 5, 2014, our Board increased the authorization to 3,000 shares of our common stock outstanding. Under the Repurchase Program, shares may be purchased in the open market, including block trades, through privately negotiated transactions, or pursuant to a trading plan separately adopted in the future. The timing, manner, price and amount of any repurchases will be at our discretion, subject to the requirements of the Securities Exchange Act of 1934, as amended, and related rules. We are not required to repurchase any shares under the Repurchase Program and it may be modified, suspended or terminated at any time for any reason. We do not intend to purchase shares from our Board or other affiliates. Under Maryland law, such repurchased shares are treated as authorized but unissued shares. For the six months ended June 30, 2014, we did not repurchase any shares under our Repurchase Program. At June 30, 2014, there were 1,493 remaining shares authorized for repurchase under our Repurchase Program.
	Revenue Recognition
	Interest income is earned and recognized on Agency Securities based on their unpaid principal balance and their contractual terms. Premiums and discounts associated with the purchase of Agency Securities are amortized or accreted into interest income over the actual lives of the securities, reflecting actual prepayments as they occur.
	Interest income on Non-Agency Securities is recognized using the effective yield method over the life of the securities based on the future cash flows expected to be received. Future cash flow projections and related effective yields are determined for each security and updated quarterly. Other than temporary impairments, which establish a new cost basis in the security for purposes of calculating effective yields, are recognized when the fair value of a security is less than its cost basis and there has been an adverse change in the future cash flows expected to be received. Other changes in future cash flows expected to be received are recognized prospectively over the remaining life of the security.
	Comprehensive Income (Loss)
	Comprehensive income (loss) refers to changes in equity during a period from transactions and other events and circumstances from non-owner sources. It includes all changes in equity during a period, except those resulting from investments by owners and distributions to owners.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2014
Accounting Changes and Error Corrections [Abstract]	'
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In June 2014, the Financial Accounting Standards Board released ASU No. 2014-11, Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, Transfers and Servicing (Topic 860). The amendment changes the accounting for repurchase financing transactions, that is, a transfer of a financial asset financed by a repurchase agreement with the same counterparty. Currently, certain of these transactions are combined and accounted for as a forward contract and reported as "Linked Transactions" on our balance sheets. Under the amendment, these arrangements will no longer be presented as Linked Transactions on our balance sheets but will instead be accounted for as purchases of Non-Agency trading securities and repurchase agreement liabilities.
	The amendment also changes the accounting for repurchase-to-maturity transactions to secured borrowing accounting. We do not currently have, and do not contemplate having, repurchase-to-maturity transactions.
	The accounting changes are effective for the Company beginning on January 1, 2015 and early adoption is prohibited. We currently account for Linked Transactions and Non-Agency Securities all on a fair value basis. Accordingly, we expect the adoption of this amendment will have no effect on our results of operations or our accumulated deficit.
	The amendment also requires certain additional disclosures about repurchase agreements beginning in the second quarter of 2015.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	Our valuation techniques for financial instruments use observable and unobservable inputs. Observable inputs reflect readily obtainable data from third party sources, while unobservable inputs reflect management’s market assumptions. The ASC Topic No. 820 “Fair Value Measurement” classifies these inputs into the following hierarchy:
	Level 1 Inputs - Quoted prices for identical instruments in active markets.
	Level 2 Inputs - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable.
	Level 3 Inputs - Prices determined using significant unobservable inputs. Unobservable inputs may be used in situations where quoted prices or observable inputs are unavailable (for example, when there is little or no market activity for an investment at the end of the period). Unobservable inputs reflect management’s assumptions about the factors that market participants would use in pricing an asset or liability, and would be based on the best information available.
	The following describes the valuation techniques used for our assets and liabilities measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy. Any transfers between levels are assumed to occur at the beginning of the reporting period.
	Cash - Cash includes cash on deposit with financial institutions. The carrying amount of cash is deemed to be its fair value and is classified as Level 1. Cash balances posted by us to counterparties or held by us from counterparties as collateral are classified as Level 2.
	Agency Securities, Available for Sale - Fair value for the Agency Securities in our MBS portfolio is based on obtaining a valuation for each Agency Security from third party pricing services and/or dealer quotes. The third party pricing services use common market pricing methods that may include pricing models that may incorporate such factors as coupons, prepayment speeds, spread to the Treasury curves and interest rate swap curves, duration, periodic and life caps and credit enhancement. If the fair value of an Agency Security is not available from the third party pricing services or such data appears unreliable, we obtain quotes from up to three dealers who make markets in similar Agency Securities. In general, the dealers incorporate common market pricing methods, including a spread measurement to the Treasury curve or interest rate swap curve as well as underlying characteristics of the particular Agency Security including coupon, periodic and life caps, collateral type, rate reset period and seasoning or age of the Agency Security. Management reviews pricing used to ensure that current market conditions are properly reflected. This review includes, but is not limited to, comparisons of similar market transactions or alternative third party pricing services, dealer quotes and comparisons to a third party pricing model. Fair values obtained from the third party pricing services for similar instruments are classified as Level 2 securities if the inputs to the pricing models used are consistent with the Level 2 definition. If quoted prices for a security are not reasonably available from the third party pricing service, but dealer quotes are, the security will be classified as a Level 2 security. If neither is available, management will determine the fair value based on characteristics of the security that we receive from the issuer and based on available market information received from dealers and classify it as a Level 3 security. At June 30, 2014 and December 31, 2013, all of our Agency Security fair values are classified as Level 2 based on the inputs used by our third party pricing services and dealer quotes.
	Non-Agency Securities Trading - The fair value for the Non-Agency Securities in our MBS portfolio is based on estimates prepared by our Portfolio Management group, which organizationally reports to our Chief Investment Officer. In preparing the estimates, our Portfolio Management group uses commercially available and proprietary models and data as well as market intelligence gained from discussions with, and transactions by, other market participants. We estimate the fair value of our Non-Agency Securities by estimating the future cash flows for each Non-Agency Security and then discounting those cash flows based on our estimates of current market yield for each individual security. Our estimates for future cash flows and current market yields incorporate such factors as collateral type, bond structure and priority of payments, coupons, prepayment speeds, defaults, delinquencies and severities. Quarterly, we compare our estimates of fair value of our Non-Agency Securities with pricing from third party pricing services, dealer marks received and recent purchase and financing transaction history to validate our assumptions of cash flow and market yield and calibrate our models. Fair values calculated in this manner are considered Level 3. At June 30, 2014 and December 31, 2013, all of our Non-Agency Security fair values are calculated in this manner and therefore were classified as Level 3.
	Repurchase Agreements - The fair value of repurchase agreements reflects the present value of the contractual cash flows discounted at the estimated LIBOR based market interest rates at the valuation date for repurchase agreements with a term equivalent to the remaining term to interest rate repricing, which may be at maturity, of our repurchase agreements. The fair value of the repurchase agreements approximates their carrying amount due to the short-term nature of these financial instruments. Our repurchase agreements are classified as Level 2.
	Obligations to Return Securities Received as Collateral - The fair value of the obligations to return securities received as collateral are based upon the prices of the related U.S. Treasury Securities obtained from a third party pricing service, which are indicative of market activity. Such obligations are classified as Level 1.
	Derivative Transactions - The fair values of our interest rate swap contracts and interest rate swaptions are valued using third party pricing services that may incorporate current interest rate curves, forward interest rate curves and market spreads to interest rate curves. Management compares pricing used to dealer quotes to ensure that the current market conditions are properly reflected. The fair values of our interest rate swap contracts and our interest rate swaptions are classified as Level 2.
	Linked Transactions - The Non-Agency Securities underlying our Linked Transactions are valued using similar techniques to those used for our other Non-Agency Securities. The value of the underlying Non-Agency Security is then netted against the carrying amount (which approximates fair value) of the repurchase agreement at the valuation date. The fair value of Linked Transactions also includes accrued interest receivable on the Non-Agency Security and accrued interest payable on the underlying repurchase agreement. Our Linked Transactions are classified as Level 3.
	The following tables provide a summary of our assets that are measured at fair value on a recurring basis at June 30, 2014 and December 31, 2013.
		Quoted				Significant Observable				Significant Unobservable				Balance at June 30, 2014
		Prices in				Inputs				Inputs
		Active				(Level 2)				(Level 3)
		Markets for Identical
		Assets
		(Level 1)
	Assets at Fair Value:
	Agency Securities, available for sale	$	—			$	1,196,872			$	—			$	1,196,872
	Non-Agency Securities, trading	$	—			$	—			$	155,783			$	155,783
	Linked Transactions, net	$	—			$	—			$	14,448			$	14,448
	Derivatives	$	—			$	25,474			$	—			$	25,474
	There were no transfers of assets or liabilities between levels of the fair value hierarchy during the quarter and six months ended June 30, 2014.
		Quoted				Significant Observable				Significant Unobservable				Balance at December 31, 2013
		Prices in				Inputs				Inputs
		Active				(Level 2)				(Level 3)
		Markets for Identical
		Assets
		(Level 1)
	Assets at Fair Value:
	Agency Securities, available for sale	$	—			$	801,777			$	—			$	801,777
	Non-Agency Securities, trading	$	—			$	—			$	143,399			$	143,399
	Linked Transactions, net	$	—			$	—			$	16,322			$	16,322
	Derivatives	$	—			$	59,703			$	—			$	59,703
	There were no transfers of assets or liabilities between levels of the fair value hierarchy during the year ended December 31, 2013.
	The following tables provide a summary of the carrying values and fair values of our financial assets and liabilities not carried at fair value but for which fair value is required to be disclosed at June 30, 2014 and December 31, 2013.
		30-Jun-14								Fair Value Measurements using:
		Carrying				Fair				Quoted Prices				Significant Observable				Significant Unobservable
		Value				Value				in Active				Inputs				Inputs
										Markets for Identical				(Level 2)				(Level 3)
										Assets
										(Level 1)
	Financial Assets:
	Cash	$	22,397			$	22,397			$	22,397			$	—			$	—
	Cash collateral posted to counterparties	$	462			$	462			$	—			$	462			$	—
	Accrued interest receivable	$	3,072			$	3,072			$	—			$	3,072			$	—
	Financial Liabilities:
	Repurchase agreements	$	1,233,195			$	1,233,195			$	—			$	1,233,195			$	—
	Cash collateral posted by counterparties	$	23,766			$	23,766			$	—			$	23,766			$	—
	Accrued interest payable	$	819			$	819			$	—			$	819			$	—
		31-Dec-13								Fair Value Measurements using:
		Carrying				Fair				Quoted Prices				Significant Observable				Significant Unobservable
		Value				Value				in Active				Inputs				Inputs
										Markets for Identical				(Level 2)				(Level 3)
										Assets
										(Level 1)
	Financial Assets:
	Cash	$	41,524			$	41,524			$	41,524			$	—			$	—
	Cash collateral posted to counterparties	$	648			$	648			$	—			$	648			$	—
	Accrued interest receivable	$	2,336			$	2,336			$	—			$	2,336			$	—
Financial Liabilities:
Repurchase agreements	$	839,405			$	839,405			$	—			$	839,405			$	—
Cash collateral posted by counterparties	$	53,314			$	53,314			$	—			$	53,314			$	—
Accrued interest payable	$	611			$	611			$	—			$	611			$	—
The following tables provide a summary of the changes in Level 3 assets measured at fair value on a recurring basis for the quarter and six months ended June 30, 2014 and June 30, 2013.
Non-Agency Securities		For the Quarter Ended								For the Six Months Ended
		30-Jun-14				30-Jun-13				30-Jun-14				30-Jun-13
Balance, beginning of period		$	142,409			$	136,752			$	143,399			$	129,946
Purchase of Non-Agency Securities, at cost		16,735				23,518				17,985				33,275
Principal repayments of Non-Agency Securities		(3,648		)		(5,371		)		(7,048		)		(10,246		)
Gain (loss) on Non-Agency Securities		288				(5,635		)		1,121				(3,426		)
Net change in discount on Non-Agency Securities		(1		)		(311		)		326				(596		)
Balance, end of period		$	155,783			$	148,953			$	155,783			$	148,953
Gain (loss) on Non-Agency Securities		$	288			$	(5,635	)		$	1,121			$	(3,426	)
Linked Transactions		For the Quarter Ended								For the Six Months Ended
		30-Jun-14				30-Jun-13				30-Jun-14				30-Jun-13
Balance, beginning of period		$	20,069			$	—			$	16,322			$	—
Linked Transaction value of purchased Non-Agency Securities		(5,965		)		—				(5,965		)		—
Cash (receipts) disbursements on Linked Transactions		(2,606		)		11,015				(3,369		)		11,015
Unrealized net gain (loss) and net interest income from Linked Transactions		2,950				(2,288		)		7,460				(2,288		)
Balance, end of period		$	14,448			$	8,727			$	14,448			$	8,727
Gains (losses) on Linked Transactions		$	2,950			$	(2,288	)		$	7,460			$	(2,288	)
The significant unobservable inputs used in the fair value measurement of our Level 3 Non-Agency Securities (inclusive of Non-Agency Securities underlying Linked Transactions) include assumptions for underlying loan collateral cumulative default rates and loss severities in the event of default, as well as discount rates.
The following tables present the range of our estimates of cumulative default and loss severities, together with the discount rates implicit in our Level 3 Non-Agency Security fair values (inclusive of Non-Agency Securities underlying Linked Transactions) at June 30, 2014 and December 31, 2013. See Note 8, "Linked Transactions" for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions.
June 30, 2014
Unobservable	Minimum			Weighted			Maximum
Level 3 Input				Average
Cumulative default	0	%		9.05	%		30.05	%
Loss severity (life)	4.8	%		35.16	%		73.1	%
Discount rate	2.59	%		4.7	%		6.5	%
Delinquency (life)	0.4	%		9.52	%		38.6	%
Voluntary prepayments (life)	7	%		9.08	%		12.7	%
December 31, 2013
Unobservable	Minimum			Weighted			Maximum
Level 3 Input				Average
Cumulative default	0	%		6.99	%		33.27	%
Loss severity (life)	0	%		31.2	%		62.6	%
Discount rate	4.01	%		5.32	%		6.5	%
Delinquency (life)	0	%		9.74	%		29.5	%
Voluntary prepayments (life)	6.7	%		9.74	%		14.8	%
Significant increases or decreases in any of these inputs in isolation would result in a significantly lower or higher fair value measurement. Generally, a change in the assumption used for the probability of cumulative default is accompanied by a directionally similar change in the assumption used for the loss severity and a directionally opposite change in the assumption used for voluntary prepayment rates (life). However, given the interrelationship between loss estimates and the discount rate, overall Non-Agency Security market conditions would likely have a more significant impact on our Level 3 fair values than changes in any one unobservable input.

Agency_Securities_Available_fo

Agency Securities, Available for Sale	6 Months Ended
	Jun. 30, 2014
Schedule of Available-for-sale Securities [Line Items]	'
Agency Securities, Available for Sale	'
	Non-Agency Securities, Trading
	All of our Non-Agency Securities are classified as trading securities and reported at their estimated fair value.  Fair value changes are reported in the statements of operations in the period in which they occur.
	During the quarter ended June 30, 2014, we completed the purchase of Non-Agency Securities with a fair value of $16,735 that were previously treated as Linked Transactions with repayment at maturity of related repurchase agreement borrowings of $10,770.
	At June 30, 2014, investments in Non-Agency Securities accounted for 11.5% of our MBS portfolio and 19.1% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8,“Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
		Non-Agency Securities
	June 30, 2014	Fair Value		Amortized			Principal		Weighted
				Cost			Amount		Average
									Coupon
	Prime Fixed	$	53,761	$	53,303		$	60,687	5	%
	Prime Hybrid	16,202		14,745			19,840		3.02	%
	Prime Floater	3,840		3,261			3,250		5.12	%
	Alt-A Fixed	73,185		69,997			88,469		5.87	%
	Alt-A Hybrid	8,795		8,231			10,473		2.48	%
	Total Non-Agency Securities	$	155,783	$	149,537		$	182,719	5.07	%
	At December 31, 2013, investments in Non-Agency Securities accounted for 15.2% of our total MBS portfolio and 26.2% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8,“Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
		Non-Agency Securities
	December 31, 2013	Fair Value		Amortized			Principal		Weighted
				Cost			Amount		Average
									Coupon
	Prime Fixed	$	51,515	$	51,922		$	57,995	4.96	%
	Prime Hybrid	17,067		15,705			21,253		3.36	%
	Prime Floater	2,117		2,001			2,000		5.41	%
	Alt-A Fixed	63,582		61,554			77,922		5.85	%
	Alt-A Hybrid	9,118		8,494			11,091		2.59	%
	Total Non-Agency Securities	$	143,399	$	139,676		$	170,261	5.02	%
	Prime/Alt-A Non-Agency Securities at June 30, 2014 and December 31, 2013 include senior tranches in securitization trusts issued between 2004 and 2007, and are collateralized by residential mortgages originated between 2002 and 2007. The loans were originally considered to be either prime or one tier below prime credit quality. Prime mortgage loans are residential mortgage loans that are considered the highest tier with the most stringent underwriting standards within the Non-Agency mortgage market, but do not carry any credit guarantee from either a U.S. Government agency or GSE. These loans were originated during a period when underwriting standards were generally weak and housing prices have dropped significantly subsequent to their origination. As a result, there is still material credit risk embedded in these vintage tranches. Alt-A, or alternative A-paper, mortgage loans are considered riskier than prime mortgage loans and less risky than sub-prime mortgage loans and are typically characterized by borrowers with less than full documentation, lower credit scores, higher loan to value ratios and a higher percentage of investment properties. These securities were generally rated below investment grade at June 30, 2014 and December 31, 2013.
	The following table summarizes the weighted average lives of our Non-Agency Securities at June 30, 2014 and December 31, 2013.
		June 30, 2014					December 31, 2013
	Weighted Average Life of all Non-Agency Securities	Fair Value		Amortized			Fair Value		Amortized
				Cost					Cost
	Less than one year	$	—	$	—		$	—	$	—
	Greater than or equal to one year and less than three years	—		—			—		—
	Greater than or equal to three years and less than five years	4,724		4,641			36,581		35,254
	Greater than or equal to five years	151,059		144,896			106,818		104,422
	Total Non-Agency Securities	$	155,783	$	149,537		$	143,399	$	139,676
	We use a third party model to calculate the weighted average lives of our Non-Agency Securities. Weighted average life is calculated based on expectations for estimated prepayments for the underlying mortgage loans of our Non-Agency Securities. These estimated prepayments are based on assumptions such as interest rates, current and future home prices, housing policy and borrower incentives. The weighted average lives of our Non-Agency Securities at June 30, 2014 and December 31, 2013 in the table above are based upon market factors, assumptions, models and estimates from the third party model and also incorporate management’s judgment and experience. The actual weighted average lives of our Non-Agency Securities could be longer or shorter than estimated.
	The following table presents the unrealized losses and estimated fair value of our Non-Agency Securities by length of time that such securities have been in a continuous unrealized loss position at June 30, 2014 and December 31, 2013.
		Unrealized Loss Position For:
		Less than 12 months					12 Months or More						Total
	As of	Fair Value		Unrealized			Fair Value		Unrealized				Fair Value		Unrealized
				Losses					Losses						Losses
	June 30, 2014	$	2,703	$	(168	)	$	5,978	$	(328	)		$	8,681	$	(496	)
	December 31, 2013	$	42,096	$	(1,089	)	$	—	$	—			$	42,096	$	(1,089	)
	Our Non-Agency Securities are subject to risk of loss with regard to principal and interest payments and at June 30, 2014 and December 31, 2013, have generally either been assigned below investment grade ratings by rating agencies, or have not been rated. We evaluate each investment based on the characteristics of the underlying collateral and securitization structure, rather than relying on the ratings assigned by rating agencies.
	In April 2014, we entered in to a long term collateral exchange agreement whereby we will receive custody of approximately $50.0 million of U.S. Treasury Securities or receive cash for two years (declining to $30.0 million for a third year) in exchange for pledging certain of our Non-Agency Securities. At June 30, 2014, the $155,783 of Non-Agency Securities on our condensed consolidated balance sheet includes securities pledged under this agreement with a fair value of $47,721. At June 30, 2014, collateral received under this agreement consisted of $22,483 of cash, which is treated as repurchase agreement borrowings on our condensed consolidated balance sheet and $12,153 of U.S. Treasury Securities in our custody which are not reflected on our condensed consolidated balance sheet.
Agency Securities	'
Schedule of Available-for-sale Securities [Line Items]	'
Agency Securities, Available for Sale	'
	Agency Securities, Available for Sale
	All of our Agency Securities are classified as available for sale securities and, as such, are reported at their estimated fair value and changes in fair value are reported as part of the statements of comprehensive income. At June 30, 2014, investments in Agency Securities accounted for 88.5% of our MBS portfolio and 80.9% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions. As of December 31, 2013, investments in Agency Securities accounted for 84.8% of our MBS portfolio and 73.8% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8, “Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
	We evaluated our Agency Securities with unrealized losses at June 30, 2014, June 30, 2013 and December 31, 2013, to determine whether there was an other than temporary impairment. The decline in value of our Agency Securities in 2013 was solely due to market conditions and not the credit quality of the assets. All of our Agency Securities are issued and guaranteed by GSEs. The GSEs have a long term credit rating of AA+. At June 30, 2014 and December 31, 2013, we also considered whether we intended to sell Agency Securities and whether it was more likely than not that we could meet our liquidity requirements and contractual obligations without selling Agency Securities. There was no other than temporary impairment for the quarter and six months ended June 30, 2014 and June 30, 2013. In December 2013, anticipating portfolio repositioning sales in the first quarter of 2014, we concluded that the December 31, 2013 unrealized losses on our 25-year and 30-year fixed rate Agency Securities represented an other than temporary impairment. Accordingly, we recognized losses totaling $(44,300) in our 2013 statements of operations, thereby establishing a new cost basis for Agency Securities with aggregate fair value of $744,600 as of December 31, 2013. We also determined that at December 31, 2013, there was no other than temporary impairment of our other Agency Securities, which are primarily 20-year and 15-year fixed rate securities.
	At June 30, 2014, we had the following securities in an unrealized gain or loss position as presented below. The components of the carrying value of our Agency Securities at June 30, 2014 are also presented below. All of our Agency Securities are fixed rate securities with a weighted average coupon of 3.23% at June 30, 2014.
	June 30, 2014
		Amortized Cost		Gross Unrealized Loss			Gross Unrealized Gain		Fair Value			Percent of Total
	Fannie Mae
	Multi-Family MBS	$	55,043	$	(37	)	$	839	$	55,845		4.7	%
	15 Year Fixed	1,085,631		(489		)	8,115		1,093,257			91.3	%
	20 Year Fixed	48,522		(1,031		)	279		47,770			4	%
	Total Fannie Mae	$	1,189,196	$	(1,557	)	$	9,233	$	1,196,872		100	%
	Total Agency Securities	$	1,189,196	$	(1,557	)	$	9,233	$	1,196,872
	As of December 31, 2013, we had the following securities in an unrealized gain or loss position as presented below. The components of the carrying value of our Agency Securities as of December 31, 2013 are also presented below. All of our Agency Securities were fixed rate securities with a weighted average coupon of 3.48% as of December 31, 2013.
	December 31, 2013
		Amortized Cost		Gross Unrealized Loss			Gross Unrealized Gain		Fair Value			Percent of Total
	Fannie Mae
	15 Year Fixed	$	29,336	$	(1,057	)	$	—	$	28,279		3.53	%
	20 Year Fixed	30,974		(2,086		)	—		28,888			3.6	%
	25 Year Fixed	52,944		—			—		52,944			6.6	%
	30 Year Fixed	691,666		—			—		691,666			86.27	%
	Total Fannie Mae	$	804,920	$	(3,143	)	$	—	$	801,777		100	%
	Total Agency Securities	$	804,920	$	(3,143	)	$	—	$	801,777
	Actual maturities of Agency Securities are generally shorter than stated contractual maturities because actual maturities of Agency Securities are affected by the contractual lives of the underlying mortgages, periodic payments of principal and prepayments of principal.
	The following table summarizes the weighted average lives of our Agency Securities at June 30, 2014 and December 31, 2013.
		June 30, 2014					December 31, 2013
	Weighted Average Life of all Agency Securities	Fair Value		Amortized			Fair Value		Amortized
				Cost					Cost
	Less than one year	$	—	$	—		$	—	$	—
	Greater than or equal to one year and less than three years	57,314		56,944			—		—
	Greater than or equal to three years and less than five years	1,059,441		1,051,998			28,279		29,336
	Greater than or equal to five years	80,117		80,254			773,498		775,584
	Total Agency Securities	$	1,196,872	$	1,189,196		$	801,777	$	804,920
	We use a third party model to calculate the weighted average lives of our Agency Securities. Weighted average life is calculated based on expectations for estimated prepayments for the underlying mortgage loans of our Agency Securities. These estimated prepayments are based on assumptions such as interest rates, current and future home prices, housing policy and borrower incentives. The weighted average lives of our Agency Securities at June 30, 2014 and December 31, 2013 in the table above are based upon market factors, assumptions, models and estimates from the third party model and also incorporate management’s judgment and experience. The actual weighted average lives of our Agency Securities could be longer or shorter than estimated.
	The following table presents the unrealized losses and estimated fair value of our Agency Securities by length of time that such securities have been in a continuous unrealized loss position at June 30, 2014 and December 31, 2013.
		Unrealized Loss Position For:
		Less than 12 Months					12 Months or More						Total
	As of	Fair Value		Unrealized			Fair Value		Unrealized				Fair Value		Unrealized
				Losses					Losses						Losses
	June 30, 2014	$	5,018	$	(37	)	$	54,139	$	(1,520	)		$	59,157	$	(1,557	)
	December 31, 2013	$	—	$	—		$	57,167	$	(3,143	)		$	57,167	$	(3,143	)
	During the six months ended June 30, 2014, we sold $743,647 of our Agency Securities, to reposition our portfolio, which resulted in realized gains of $8.8 million. We did not have any sales of Agency Securities for the quarter ended June 30, 2014, however, we realized a loss of $(34) due to a settlement adjustment on the Agency Securities sales in the first quarter. During the quarter and six months ended June 30, 2013, we did not sell any Agency Securities.

NonAgency_Securities_Trading

Non-Agency Securities, Trading	6 Months Ended
	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Non-Agency Securities, Trading	'
	Non-Agency Securities, Trading
	All of our Non-Agency Securities are classified as trading securities and reported at their estimated fair value.  Fair value changes are reported in the statements of operations in the period in which they occur.
	During the quarter ended June 30, 2014, we completed the purchase of Non-Agency Securities with a fair value of $16,735 that were previously treated as Linked Transactions with repayment at maturity of related repurchase agreement borrowings of $10,770.
	At June 30, 2014, investments in Non-Agency Securities accounted for 11.5% of our MBS portfolio and 19.1% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8,“Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
		Non-Agency Securities
	June 30, 2014	Fair Value		Amortized			Principal		Weighted
				Cost			Amount		Average
									Coupon
	Prime Fixed	$	53,761	$	53,303		$	60,687	5	%
	Prime Hybrid	16,202		14,745			19,840		3.02	%
	Prime Floater	3,840		3,261			3,250		5.12	%
	Alt-A Fixed	73,185		69,997			88,469		5.87	%
	Alt-A Hybrid	8,795		8,231			10,473		2.48	%
	Total Non-Agency Securities	$	155,783	$	149,537		$	182,719	5.07	%
	At December 31, 2013, investments in Non-Agency Securities accounted for 15.2% of our total MBS portfolio and 26.2% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8,“Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
		Non-Agency Securities
	December 31, 2013	Fair Value		Amortized			Principal		Weighted
				Cost			Amount		Average
									Coupon
	Prime Fixed	$	51,515	$	51,922		$	57,995	4.96	%
	Prime Hybrid	17,067		15,705			21,253		3.36	%
	Prime Floater	2,117		2,001			2,000		5.41	%
	Alt-A Fixed	63,582		61,554			77,922		5.85	%
	Alt-A Hybrid	9,118		8,494			11,091		2.59	%
	Total Non-Agency Securities	$	143,399	$	139,676		$	170,261	5.02	%
	Prime/Alt-A Non-Agency Securities at June 30, 2014 and December 31, 2013 include senior tranches in securitization trusts issued between 2004 and 2007, and are collateralized by residential mortgages originated between 2002 and 2007. The loans were originally considered to be either prime or one tier below prime credit quality. Prime mortgage loans are residential mortgage loans that are considered the highest tier with the most stringent underwriting standards within the Non-Agency mortgage market, but do not carry any credit guarantee from either a U.S. Government agency or GSE. These loans were originated during a period when underwriting standards were generally weak and housing prices have dropped significantly subsequent to their origination. As a result, there is still material credit risk embedded in these vintage tranches. Alt-A, or alternative A-paper, mortgage loans are considered riskier than prime mortgage loans and less risky than sub-prime mortgage loans and are typically characterized by borrowers with less than full documentation, lower credit scores, higher loan to value ratios and a higher percentage of investment properties. These securities were generally rated below investment grade at June 30, 2014 and December 31, 2013.
	The following table summarizes the weighted average lives of our Non-Agency Securities at June 30, 2014 and December 31, 2013.
		June 30, 2014					December 31, 2013
	Weighted Average Life of all Non-Agency Securities	Fair Value		Amortized			Fair Value		Amortized
				Cost					Cost
	Less than one year	$	—	$	—		$	—	$	—
	Greater than or equal to one year and less than three years	—		—			—		—
	Greater than or equal to three years and less than five years	4,724		4,641			36,581		35,254
	Greater than or equal to five years	151,059		144,896			106,818		104,422
	Total Non-Agency Securities	$	155,783	$	149,537		$	143,399	$	139,676
	We use a third party model to calculate the weighted average lives of our Non-Agency Securities. Weighted average life is calculated based on expectations for estimated prepayments for the underlying mortgage loans of our Non-Agency Securities. These estimated prepayments are based on assumptions such as interest rates, current and future home prices, housing policy and borrower incentives. The weighted average lives of our Non-Agency Securities at June 30, 2014 and December 31, 2013 in the table above are based upon market factors, assumptions, models and estimates from the third party model and also incorporate management’s judgment and experience. The actual weighted average lives of our Non-Agency Securities could be longer or shorter than estimated.
	The following table presents the unrealized losses and estimated fair value of our Non-Agency Securities by length of time that such securities have been in a continuous unrealized loss position at June 30, 2014 and December 31, 2013.
		Unrealized Loss Position For:
		Less than 12 months					12 Months or More					Total
	As of	Fair Value		Unrealized			Fair Value		Unrealized			Fair Value		Unrealized
				Losses					Losses					Losses
	June 30, 2014	$	2,703	$	(168	)	$	5,978	$	(328	)	$	8,681	$	(496	)
	December 31, 2013	$	42,096	$	(1,089	)	$	—	$	—		$	42,096	$	(1,089	)
	Our Non-Agency Securities are subject to risk of loss with regard to principal and interest payments and at June 30, 2014 and December 31, 2013, have generally either been assigned below investment grade ratings by rating agencies, or have not been rated. We evaluate each investment based on the characteristics of the underlying collateral and securitization structure, rather than relying on the ratings assigned by rating agencies.
	In April 2014, we entered in to a long term collateral exchange agreement whereby we will receive custody of approximately $50.0 million of U.S. Treasury Securities or receive cash for two years (declining to $30.0 million for a third year) in exchange for pledging certain of our Non-Agency Securities. At June 30, 2014, the $155,783 of Non-Agency Securities on our condensed consolidated balance sheet includes securities pledged under this agreement with a fair value of $47,721. At June 30, 2014, collateral received under this agreement consisted of $22,483 of cash, which is treated as repurchase agreement borrowings on our condensed consolidated balance sheet and $12,153 of U.S. Treasury Securities in our custody which are not reflected on our condensed consolidated balance sheet.

Linked_Transactions

Linked Transactions	6 Months Ended
	Jun. 30, 2014
Linked Transactions Disclosure [Abstract]	'
Linked Transactions	'
	Linked Transactions
	Our Linked Transactions are evaluated on a combined basis, reported as forward (derivative) instruments and presented as assets on our balance sheets at fair value. The fair value of Linked Transactions reflect the value of the underlying Non-Agency MBS, linked repurchase agreement borrowings and accrued interest receivable and payable on such instruments. Our Linked Transactions are not designated as hedging instruments and, as a result, the change in the fair value and net interest income from Linked Transactions is reported in other income on our statements of operations.
	The following tables present information about our Non-Agency Securities and repurchase agreements underlying our Linked Transactions at June 30, 2014 and December 31, 2013. Our Non-Agency Securities underlying our Linked Transactions represent approximately 8.54% and 13.0% of our overall investment in MBS at June 30, 2014 and December 31, 2013, respectively.
	June 30, 2014
	Linked Repurchase Agreements							Linked Non-Agency Securities
	Maturity or Repricing	Balance			Weighted Average Interest Rate			Non-Agency MBS		Fair Value			Amortized		Par/Current		Weighted Average Coupon
													Cost		Face		Rate
	Within 30 days	$	5,072		1.91	%		Prime		$	110,846		$	109,709	$	114,306	3.11	%
	31 days to 60 days	36,605			1.03	%		Alt-A		15,404			14,760		19,190		6.05	%
	61 days to 90 days	63,752			0.98	%		Total		$	126,250		$	124,469	$	133,496	3.47	%
	Greater than 90 days	6,310			2.03	%
	Total	$	111,739		1.1	%
	Not included in the tables above is $63 of accrued interest payable from Linked Transactions included in our condensed consolidated balance sheet at June 30, 2014.
	December 31, 2013
	Linked Repurchase Agreements							Linked Non-Agency Securities
	Maturity or Repricing	Balance			Weighted Average Interest Rate			Non-Agency MBS		Fair Value			Amortized Cost		Par/Current Face		Weighted Average Coupon Rate
	Within 30 days	$	8,177		1.88	%		Prime		$	112,956		$	116,631	$	121,571	3	%
	31 days to 60 days	44,974			1.23	%		Alt-A		27,989			27,788		35,822		4.71	%
	61 days to 90 days	71,389			1.09	%		Total		$	140,945		$	144,419	$	157,393	3.34	%
	Greater than 90 days	—			0	%
	Total	$	124,540		1.19	%
	Not included in the tables above is $83 of accrued interest payable from Linked Transactions included in our condensed consolidated balance sheet as of December 31, 2013.
	The following table presents certain information about the components of the unrealized net gains and net interest income from Linked Transactions included in our condensed consolidated statements of operations for the quarter and six months ended June 30, 2014 and June 30, 2013.
		For the Quarter Ended							For the Six Months Ended
	Unrealized Net Gain and Net Interest Income from Linked Transactions	30-Jun-14			30-Jun-13				30-Jun-14			30-Jun-13
	Interest income attributable to MBS underlying Linked Transactions	$	1,300		$	39			$	2,869		$	39
	Interest expense attributable to linked repurchase agreements underlying Linked Transactions	(161		)	(915		)		(450		)	(915		)
	Change in fair value of Linked Transactions included in earnings	1,811			(1,412		)		5,041			(1,412		)
	Unrealized net gain (loss) and net interest income (loss) from Linked Transactions	$	2,950		$	(2,288	)		$	7,460		$	(2,288	)

Repurchase_Agreements

Repurchase Agreements	6 Months Ended
	Jun. 30, 2014
Disclosure of Repurchase Agreements [Abstract]	'
Repurchase Agreements	'
	Repurchase Agreements
	At June 30, 2014, we had MRAs with 29 counterparties and had $1,233,195 in outstanding borrowings with 23 of those counterparties. At December 31, 2013, we had MRAs with 27 counterparties and had $839,405 in outstanding borrowings with 20 of those counterparties. See Note 8, “Linked Transactions” for additional discussion of repurchase agreements that are accounted for as a component of Linked Transactions.
	The following tables represent the contractual repricing and other information regarding our repurchase agreements to finance our MBS purchases at June 30, 2014 and December 31, 2013.
	30-Jun-14	Repurchase Agreements		Weighted		Weighted		Haircut for
				Average		Average		Repurchase Agreements (1)
				Contractual		Maturity
				Rate		in days
	Agency Securities	$	1,126,421	0.34	%	39		4.79	%
	Non-Agency Securities	106,774		1.95	%	242		24.46	%
	Total or Weighted Average	$	1,233,195	0.48	%	57		6.49	%
	(1) The Haircut represents the weighted average margin requirement, or the percentage amount by which the collateral value must exceed the loan amount.
	31-Dec-13	Repurchase Agreements		Weighted		Weighted		Haircut for
				Average		Average		Repurchase Agreements (1)
				Contractual Rate		Maturity in
						days
	Agency Securities	$	731,782	0.42	%	33		4.9	%
	Non-Agency Securities	107,623		1.96	%	46		25.39	%
	Total or Weighted Average	$	839,405	0.61	%	35		7.53	%
	(1) The Haircut represents the weighted average margin requirement, or the percentage amount by which the collateral value must exceed the loan amount.
		30-Jun-14				31-Dec-13
	Maturing or Repricing	Repurchase Agreements		Weighted		Repurchase Agreements				Weighted
				Average						Average
				Contractual Rate						Contractual Rate
	Within 30 days	$	657,358	0.47	%	$	380,744			0.67	%
	31 days to 60 days	288,287		0.39	%	408,054				0.49	%
	61 days to 90 days	165,429		0.46	%	40,362				1	%
	Greater than 90 days	122,121		0.81	%	10,245				2.1	%
	Total or Weighted Average	$	1,233,195	0.48	%	$	839,405			0.61	%
	We have 10 repurchase agreement counterparties that individually account for between 5% and 10% of our aggregate borrowings. In total, these counterparties account for approximately 68.50% of our repurchase agreement borrowings outstanding at June 30, 2014.
	During the quarter and six months ended June 30, 2014, we did not purchase or sell any U.S. Treasury Securities. During the quarter and six months ended June 30, 2013, we sold short $301,903 of U.S. Treasury Securities and purchased $70,126 resulting in a realized loss of $(390). The outstanding balance resulted in an unrealized loss of $(2,716).

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivatives	'
	Derivatives
	In addition to the Linked Transactions described in Note 8, “Linked Transactions,” we enter into derivative transactions to manage our interest rate risk exposure. These transactions include entering into interest rate swap contracts and interest rate swaptions. These transactions are designed to lock in funding costs for repurchase agreements associated with our assets in such a way to help assure the realization of net interest margins. Such transactions are based on assumptions about prepayments on our Agency Securities which, if not realized, will cause transaction results to differ from expectations. Our derivatives are carried on our balance sheets as assets or as liabilities at their fair value. We do not designate our derivatives as cash flow hedges and as such, we recognize changes in the fair value of these derivatives through earnings.
	We have agreements with our swap (including swaption) counterparties that provide for the posting of collateral based on the fair values of our interest rate swap contracts. Through this margin process, either we or our swap counterparty may be required to pledge cash or Agency Securities as collateral. Collateral requirements vary by counterparty and change over time based on the fair value, notional amount and remaining term of the contracts. Certain interest rate swap contracts provide for cross collateralization and cross default with repurchase agreements and other contracts with the same counterparty.
	Interest rate swaptions generally provide us the option to enter into an interest rate swap agreement at a certain point of time in the future with a predetermined notional amount, stated term and stated rate of interest in the fixed leg and interest rate index on the floating leg.
	The following tables present information about interest rate swap contracts and interest rate swaptions which are included in derivatives on the accompanying condensed consolidated balance sheets as of June 30, 2014 and December 31, 2013.
	June 30, 2014
	Derivative Type		Remaining / Underlying Term		Weighted Average Remaining Swap / Option Term (Months)		Weighted Average Rate			Notional Amount				Asset Fair Value (1)				Liability Fair Value (1)
	Interest rate swap contracts		0-12 Months		0		0	%		$	—			$	—			$	—
	Interest rate swap contracts		13-24 Months		0		0	%		—				—				—
	Interest rate swap contracts		25-36 Months		0		0	%		—				—				—
	Interest rate swap contract		37-48 Months		43		0.73	%		100,000				950				—
	Interest rate swap contracts		49-60 Months		0		0	%		—				—				—
	Interest rate swap contracts		61-72 Months		0		0	%		—				—				—
	Interest rate swap contracts		73-84 Months		0		0	%		—				—				—
	Interest rate swap contracts		85-96 Months		0		0	%		—				—				—
	Interest rate swap contracts		97-108 Months		104		1.76	%		601,250				20,703				—
	Interest rate swap contracts		109-120 Months		112		2.05	%		100,000				3,658				—
	Interest rate swaptions		60 Months		3		2.73	%		750,000				163				—
	Total or Weighted Average				52		2.19	%		$	1,551,250			$	25,474			$	—
	-1	See Note 5, “Fair Value of Financial Instruments” for additional discussion.
	December 31, 2013
	Derivative Type		Remaining / Underlying Term		Weighted Average Remaining Swap / Option Term (Months)		Weighted Average Rate			Notional Amount				Asset Fair Value (1)				Liability Fair Value (1)
	Interest rate swap contracts		0-12 Months		0		0	%		$	—			$	—			$	—
	Interest rate swap contracts		13-24 Months		0		0	%		—				—				—
	Interest rate swap contracts		25-36 Months		0		0	%		—				—				—
	Interest rate swap contracts		37-48 Months		46		0.55	%		50,000				801				—
	Interest rate swap contracts		49-60 Months		53		0.92	%		50,000				532				—
	Interest rate swap contracts		61-72 Months		0		0	%		—				—				—
	Interest rate swap contracts		73-84 Months		0		0	%		—				—				—
	Interest rate swap contracts		85-96 Months		0		0	%		—				—				—
	Interest rate swap contracts		97-108 Months		105		1.5	%		175,000				15,023				—
	Interest rate swap contracts		109-120 Months		112		1.91	%		526,250				36,463				—
	Interest rate swaptions		60 Months		9		2.73	%		750,000				6,884				—
	Total or Weighted Average				58		2.19	%		$	1,551,250			$	59,703			$	—
	-1	See Note 5, “Fair Value of Financial Instruments” for additional discussion.
	We have netting arrangements in place with all derivative counterparties pursuant to standard documentation developed by the International Swap and Derivatives Association. We are also required to post cash collateral to counterparties or have cash collateral posted by counterparties to us based upon the net underlying market value of our open positions with the counterparty.
	The following tables present information about interest rate swap contracts and interest rate swaptions and the potential effects of the master netting arrangements if we were to offset the assets and liabilities of these financial instruments on the accompanying balance sheets. Currently, we present these financial instruments at their gross amounts and they are included in derivatives at fair value on the accompanying condensed consolidated balance sheet as of June 30, 2014.
	30-Jun-14						Gross Amounts Not Offset
							in the
							Condensed Consolidated Balance Sheet
	Assets		Gross and Net Amounts				Financial				Cash				Net Amount
			of Assets				Instruments				Collateral
			Presented in the Condensed Consolidated
			Balance Sheet
	Interest rate swap contracts		$	25,311			$	—			$	(23,290	)		$	2,021
	Interest rate swaptions		163				—				—				163
	Totals		$	25,474			$	—			$	(23,290	)		$	2,184
	We did not have any derivatives in a liability position on our condensed consolidated balance sheet at June 30, 2014.
	The following tables present information about interest rate swap contracts and interest rate swaptions and the potential effects of netting if we were to offset the assets and liabilities of these financial instruments on the accompanying balance sheets. Currently, we present these financial instruments at their gross amounts and they are included in derivatives, at fair value on the accompanying condensed consolidated balance sheet as of December 31, 2013.
	December 31, 2013						Gross Amounts Not Offset in the
							Condensed Consolidated Balance Sheet
	Assets		Gross and Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet				Financial Instruments				Cash Collateral				Net Amount
	Interest rate swap contracts		$	52,819			$	—			$	(52,315	)		$	504
	Interest rate swaptions		6,884				—				—				$	6,884
	Totals		$	59,703			$	—			$	(52,315	)		$	7,388
	We did not have any derivatives in a liability position on our condensed consolidated balance sheet at December 31, 2013.
	The following table represents the location and information regarding our derivatives which are included in total Other Income (Loss) in the accompanying condensed consolidated statements of operations for the quarter and six months ended June 30, 2014 and June 30, 2013.
					Income (Loss) Recognized
					For the Quarter Ended								For the Six Months Ended
	Derivatives		Location on condensed consolidated statements of operations		30-Jun-14				30-Jun-13				30-Jun-14				30-Jun-13
	Interest rate swap contracts:
	Interest income		Realized loss on derivatives		$	263			$	204			$	503			$	317
	Interest expense		Realized loss on derivatives		(3,360		)		(2,193		)		(6,706		)		(3,256		)
Changes in fair value		Unrealized gain (loss) on derivatives		(13,142		)		36,970				(29,011		)		40,086
				$	(16,239	)		$	34,981			$	(35,214	)		$	37,147
Interest rate swaptions:
Changes in fair value		Unrealized gain (loss) on derivatives		(2,561		)		6,211				(6,721		)		6,540
				$	(2,561	)		$	6,211			$	(6,721	)		$	6,540
Totals				$	(18,800	)		$	41,192			$	(41,935	)		$	43,687

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Management Agreement with ARRM
	As discussed in Note 15 “Related Party Transactions,” we are externally managed by ARRM pursuant to a management agreement, (the “Management Agreement”), which was most recently amended on March 5, 2014. The Management Agreement entitles ARRM to receive a management fee payable monthly in arrears in an amount equal to 1/12th of (a) 1.5% of gross equity raised (including our initial public offering and private placement equity) up to $1 billion plus (b) 1.0% of gross equity raised in excess of $1 billion. The cost of repurchased stock and any dividend representing a return of capital for tax purposes will reduce the amount of gross equity raised used to calculate the monthly management fee. For the quarter and six months ended June 30, 2014, we reimbursed ARRM $95 and $179, respectively, for other expenses incurred on our behalf. For the quarter and six months ended June 30, 2013, we reimbursed ARRM $27 and $37, respectively, for other expenses incurred on our behalf. ARRM is further entitled to receive a termination fee from us under certain circumstances. The ARRM monthly management fee is not calculated based on the performance of our portfolio. Accordingly, the payment of our monthly management fee may not decline in the event of a decline in our earnings and may cause us to incur losses.
	ARRM is also the external manager of ARMOUR Residential REIT, Inc. ("ARMOUR"), a publicly traded REIT, which invests in a leveraged portfolio of Agency Securities. Our executive officers also serve as the executive officers of ARMOUR.
	Indemnifications and Litigation
	We enter into certain contracts that contain a variety of indemnifications to third parties, principally with ARRM and brokers. The maximum potential amount of future payments we could be required to make under these indemnification provisions is unknown. We have not incurred any costs to defend lawsuits or settle claims related to these indemnification agreements. As a result, the estimated fair value of these agreements is not material. Accordingly, we have no liabilities recorded for these agreements as of June 30, 2014 and December 31, 2013.
	We are not party to any pending, threatened or contemplated litigation.

Stock_Based_Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock Based Compensation	'
	Stock Based Compensation
	Stock Incentive Plan
	On October 2, 2012, we adopted the 2012 Stock Incentive Plan (the "Plan") to attract, retain and reward directors and other persons who provide services to us in the course of operations (collectively, "Eligible Individuals").
	The Plan provides for grants of common stock, restricted shares of common stock, stock options, performance shares, performance units, stock appreciation rights and other equity and cash-based awards (collectively “Awards”), and will be subject to a ceiling amount of shares available for issuance under the Plan. Pursuant to the Plan, the maximum number of shares of common stock reserved for the grant of awards thereunder is equal to 3.0% of the total issued and outstanding shares of common stock (on a fully diluted basis) at the time of the grant of the award (other than any shares of common stock issued or subject to awards made pursuant to the Plan).
	The Plan allows for the Board to expand the types of awards available under the Plan and determine the maximum number of shares that may underlie these awards in any one year to any Eligible Individual. If an award granted under the Plan expires or terminates, the shares subject to any portion of the award that expires or terminates without having been exercised or paid, as the case may be, will again become available for the issuance of additional awards.
	Awards under the Plan
	As of June 30, 2014, there were 360 shares available for awards under the Plan. No awards have been made to date.
	Directors Fees
	In the first quarter of 2014, we began paying to our non-employee directors a fee payable in common stock, or a combination of stock and cash at the option of the director. The number of shares issued is determined by dividing the chosen dollar amount of these fees by the closing market price for our stock at the end of each quarter.

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Stockholders' Equity	'
	Stockholders’ Equity
	Dividends
	The following table presents our common stock dividend transactions for the six months ended June 30, 2014.
	Record Date	Payment Date	Rate per		Aggregate
			common share		amount paid to
					holders of record
	15-Jan-14	30-Jan-14	$	0.15	$	1,799
	14-Feb-14	27-Feb-14	$	0.15	$	1,799
	17-Mar-14	28-Mar-14	$	0.15	$	1,799
	15-Apr-14	29-Apr-14	$	0.15	$	1,799
	15-May-14	29-May-14	$	0.15	$	1,799
	16-Jun-14	27-Jun-14	$	0.15	$	1,800
	Total dividends paid				$	10,795

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	We have elected to be taxed as a REIT under the Code. We will generally not be subject to federal income tax to the extent that we distribute our taxable income to our stockholders and as long as we satisfy the ongoing REIT requirements under the Code including meeting certain asset, income and stock ownership tests.
	The following table reconciles our GAAP net income (loss) to estimated REIT taxable income for the quarter and six months ended June 30, 2014 and June 30, 2013.
		For the Quarter Ended						For the Six Months Ended
		30-Jun-14			30-Jun-13			30-Jun-14			30-Jun-13
	GAAP net income (loss)	$	(8,776	)	$	38,237		$	(10,639	)	$	49,213
	Book to tax differences:
	Net book to tax differences on Non-Agency Securities and Linked Transactions	(2,003		)	8,359			(5,699		)	6,634
	Unrealized loss on U.S. Treasury Securities sold short	—			2,716			—			2,716
	Realized capital loss on short sale of U.S. Treasury Securities	—			390			—			390
	(Gain) loss on sale of Agency Securities	34			—			(8,776		)	—
	Amortization of deferred hedging gains	146			—			291			—
	Net premium amortization differences	(181		)	—			(809		)	—
	Changes in interest rate contracts	15,703			(43,181		)	35,732			(46,626		)
	Other	(6		)	—			(5		)	2
	Estimated taxable income	$	4,917		$	6,521		$	10,095		$	12,329
	The aggregate tax basis of our assets and liabilities was less than our total Stockholders’ Equity at June 30, 2014 by approximately $(33,730), or approximately $(2.81) per share (based on the 11,999 shares then outstanding).
	We are required and intend to timely distribute substantially all of our taxable REIT income in order to maintain our REIT status under the Code. Total dividend payments to stockholders were $5,398 and $10,795 for the quarter and six months ended June 30, 2014. Our estimated taxable REIT income available to pay dividends was $4,917 and $10,095 for the quarter and six months ended June 30, 2014. Our taxable REIT income and dividend requirements to maintain our REIT status are determined on an annual basis. Dividends in excess of taxable REIT income for the year (including amounts carried forward from prior years) will generally not be taxable to common stockholders.
	Net capital losses realized in 2013 and 2014 will be available to offset future capital gains realized through 2018 and 2019, respectively.
	Our management is responsible for determining whether tax positions taken by us are more likely than not to be sustained on their merits. We have no material unrecognized tax benefits or material uncertain tax positions.

Related_Party_Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Related Party Transactions
	We are externally managed by ARRM pursuant to the Management Agreement. All of our executive officers are also employees of ARRM. ARRM manages our day-to-day operations, subject to the direction and oversight of the Board. The Management Agreement expires after an initial term of five years on October 5, 2017 and is thereafter automatically renewed for successive one year terms, unless terminated under certain circumstances. Either party must provide 180 days prior written notice of any such termination.
	Under the terms of the Management Agreement, ARRM is responsible for costs incident to the performance of its duties, such as compensation of its employees and various overhead expenses. ARRM is responsible for the following primary roles:
	•	Advising us with respect to, arranging for and managing the acquisition, financing, management and disposition of, elements of our investment portfolio;
	•	Evaluating the duration risk and prepayment risk within the investment portfolio and arranging borrowing and hedging strategies;
	•	Coordinating capital raising activities;
	•	Advising us on the formulation and implementation of operating strategies and policies, arranging for the acquisition of assets, monitoring the performance of those assets  and providing administrative and managerial services in connection with our day-to-day operations; and
	•	Providing executive and administrative personnel, office space and other appropriate services required in rendering management services to us.
	In accordance with the Management Agreement, we incurred $915 and $1,828, respectively, in management fees to ARRM for the quarter and six months ended June 30, 2014. For the quarter and six months ended June 30, 2013, we incurred $790 and $1,352, respectively, in management fees.
	We are required to take actions as may be reasonably required to permit and enable ARRM to carry out its duties and obligations. We are also responsible for any costs and expenses that ARRM incurred solely on behalf of us other than the various overhead expenses specified in the terms of the Management Agreement. For the quarter and six months ended June 30, 2014, we reimbursed ARRM $95 and $179, respectively, for other expenses incurred on our behalf. For the quarter and six months ended June 30, 2013, we reimbursed ARRM $27 and $37, respectively, for other expenses incurred on our behalf.
	Also, JAVELIN and ARRM entered into a sub-management agreement with SBBC, an entity jointly owned by Daniel C. Staton and Marc H. Bell, each of whom is a member of our board of directors. Pursuant to the sub-management agreement, ARRM is responsible for paying a sub-management fee to SBBC in an amount equal to a monthly retainer of $115 and a sub-management fee of 25% of the net management fee earned by ARRM under the Management Agreement. The sub-management agreement continues in effect until it is terminated in accordance with its terms.

Interest_Rate_Risk

Interest Rate Risk	6 Months Ended
	Jun. 30, 2014
Interest Rate Risk [Abstract]	'
Interest Rate Risk	'
	Interest Rate Risk
	Our primary market risk is interest rate risk. Interest rates are highly sensitive to many factors, including governmental monetary and tax policies, domestic and international economic and political considerations and other factors beyond our control. Changes in the general level of interest rates can affect net interest income, which is the difference between the interest income earned and the interest expense incurred in connection with the liabilities, by affecting the spread between the interest-earning assets and interest-bearing liabilities. Changes in the level of interest rates also can affect the value of MBS and our ability to realize gains from the sale of these assets. A decline in the value of the MBS pledged as collateral for borrowings under repurchase agreements could result in the counterparties demanding additional collateral pledges or liquidation of some of the existing collateral to reduce borrowing levels.

Subsequent_events

Subsequent events	6 Months Ended
	Jun. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	On July 30, 2014, a cash dividend of $0.15 per outstanding common share, or $1,800 in the aggregate, was paid to holders of record on July 15, 2014.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Cash	'
	Cash
	Cash includes cash on deposit with financial institutions. We may maintain deposits in federally insured financial institutions in excess of federally insured limits. However, management believes we are not exposed to significant credit risk due to the financial position and creditworthiness of the depository institutions in which those deposits are held.
Cash Collateral Posted/Held	'
	Cash Collateral Posted To/By Counterparties
	Cash collateral posted to/by counterparties represents cash posted by us to counterparties or posted by counterparties to us as collateral for our interest rate swap contracts (including swaptions) and repurchase agreements on our MBS.
MBS, at Fair Value	'
	MBS, at Fair Value
	We generally intend to hold most of our MBS for extended periods of time. We may, from time to time, sell any of our MBS as part of the overall management of our MBS portfolio. Management determines the appropriate classifications of the securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date.
	Purchases and sales of our MBS are recorded on the trade date. However, if on the purchase settlement date, a repurchase agreement is used to finance the purchase of an MBS with the same counterparty and such transactions are determined to be linked, then the MBS and linked repurchase borrowing will be reported on the same settlement date as Linked Transactions (see below).
	Agency Securities
	At June 30, 2014 and December 31, 2013, all of our Agency Securities were classified as available for sale securities. Agency Securities classified as available for sale are reported at their estimated fair values with unrealized gains and losses excluded from earnings and reported as part of the condensed consolidated statements of comprehensive income (loss).
	We evaluate Agency Securities for other than temporary impairment at least on a quarterly basis and more frequently when economic or market concerns warrant such evaluation. We consider an impairment to be other than temporary if we (1) have the intent to sell the Agency Securities, (2) believe it is more likely than not that we will be required to sell the securities before recovery (for example, because of liquidity requirements or contractual obligations) or (3) a credit loss exists. Impairment losses recognized establish a new cost basis for the related Agency Securities.
	Non-Agency Securities
	At June 30, 2014 and December 31, 2013, all of our Non-Agency Securities were classified as trading securities. Non-Agency Securities classified as trading are reported at their estimated fair values with unrealized gains and losses included in other income (loss) as a component of the statements of operations. We estimate future cash flows for each Non-Agency Security and then discount those cash flows based on our estimates of current market yield for each individual security. We then compare our calculated price with our pricing services and/or dealer marks. Our estimates for future cash flows and current market yields incorporate such factors as coupons, prepayment speeds, defaults, delinquencies and severities.
Accrued Interest Receivable and Payable	'
	Accrued Interest Receivable and Payable
	Accrued interest receivable includes interest accrued between payment dates on MBS. Accrued interest payable includes interest payable on our repurchase agreements.
Repurchase Agreements	'
	Repurchase Agreements
	We finance the acquisition of our MBS through the use of repurchase agreements. Our repurchase agreements are secured by our MBS and bear interest rates that have historically moved in close relationship to the Federal Funds Rate and the London Interbank Offered Rate (“LIBOR”). Under these repurchase agreements, we sell MBS to a lender and agree to repurchase the same MBS in the future for a price that is higher than the original sales price. The difference between the sales price that we receive and the repurchase price that we pay represents interest paid to the lender. A repurchase agreement operates as a financing arrangement (with the exception of repurchase agreements accounted for as a component of a Linked Transaction described below) under which we pledge our MBS as collateral to secure a loan which is equal in value to a specified percentage of the estimated fair value of the pledged collateral. We retain beneficial ownership of the pledged collateral. At the maturity of a repurchase agreement, we are required to repay the loan and concurrently receive back our pledged collateral from the lender or, with the consent of the lender, we may renew such agreement at the then prevailing interest rate. The repurchase agreements may require us to pledge additional assets to the lender in the event the estimated fair value of the existing pledged collateral declines.
	In addition to the repurchase agreement financing discussed above, we may enter into reverse repurchase agreements with certain of our repurchase agreement counterparties. Under a typical reverse repurchase agreement, we purchase U.S. Treasury Securities from a borrower in exchange for cash and agree to sell the same securities in the future in exchange for a price that is higher than the original purchase price. The difference between the purchase price originally paid and the sale price represents interest received from the borrower. Reverse repurchase agreement receivables and repurchase agreement liabilities are presented net when they meet certain criteria, including being with the same counterparty, being governed by the same master repurchase agreement ("MRA"), settlement through the same brokerage or clearing account and maturing on the same day.
Obligations to Return Securities Received as Collateral, at Fair Value	'
	Obligations to Return Securities Received as Collateral, at Fair Value
	At certain times, we also sell to third parties the U.S. Treasury Securities received as collateral for reverse repurchase agreements and recognize the resulting obligation to return said U.S. Treasury Securities as a liability on our condensed consolidated balance sheets. Interest is recorded on the repurchase agreements, reverse repurchase agreements and U.S. Treasury Securities sold short on an accrual basis and presented as net interest expense. Both parties to the transaction have the right to make daily margin calls based on changes in the fair value of the collateral received and/or pledged.
Derivatives, at Fair Value	'
	Derivatives, at Fair Value
	We recognize all derivatives as either assets or liabilities at fair value on our condensed consolidated balance sheets. All changes in the fair values of our derivatives are reflected in our condensed consolidated statements of operations. We designate derivatives as hedges for tax purposes and any unrealized derivative gains or losses do not affect our distributable net taxable income.
Linked Transactions	'
	Linked Transactions
	The initial purchase of Non-Agency Securities and the related contemporaneous repurchase financing of such MBS with the same counterparty are considered part of the same arrangement, or a “Linked Transaction,” when certain criteria are met. Our acquisition of a Non-Agency Security and a related repurchase financing provided by the seller are generally considered to be linked if the initial transfer of and repurchase financing are contractually contingent, or there is a limited secondary market for the purchased security. The components of a Linked Transaction are evaluated on a combined basis and in totality, accounted for as a forward contract and reported as “Linked Transactions” on our balance sheets. Changes in the fair value of the Non-Agency Securities and repurchase liabilities underlying the Linked Transactions and associated interest income and expense are reported as “unrealized net gains and net interest income from Linked Transactions” on our statements of operations and are not included in other comprehensive loss. When the linking criteria are no longer met, the initial transfer (i.e., the purchase of a security) and repurchase financing will no longer be treated as a Linked Transaction and will be evaluated and reported separately as a MBS purchase and repurchase financing.
Preferred Stock	'
	Preferred Stock
	At June 30, 2014, we were authorized to issue up to 25,000 shares of preferred stock, par value $0.001 per share, with such designations, voting and other rights and preferences as may be determined from time to time by our Board of Directors ("Board") or a committee thereof. We have not issued any preferred stock to date.
Common Stock	'
	Common Stock
	At June 30, 2014, we were authorized to issue up to 250,000 shares of common stock, par value $0.001 per share, with such designations, voting and other rights and preferences as may be determined from time to time by our Board. We had 11,999 shares of common stock issued and outstanding at June 30, 2014 and 11,993 shares of common stock issued and outstanding at December 31, 2013.
	Common Stock Repurchased
	On October 30, 2013, we announced that our Board had authorized a stock repurchase program of up to 2,000 shares of our common stock outstanding (the “Repurchase Program”). On March 5, 2014, our Board increased the authorization to 3,000 shares of our common stock outstanding. Under the Repurchase Program, shares may be purchased in the open market, including block trades, through privately negotiated transactions, or pursuant to a trading plan separately adopted in the future. The timing, manner, price and amount of any repurchases will be at our discretion, subject to the requirements of the Securities Exchange Act of 1934, as amended, and related rules. We are not required to repurchase any shares under the Repurchase Program and it may be modified, suspended or terminated at any time for any reason. We do not intend to purchase shares from our Board or other affiliates. Under Maryland law, such repurchased shares are treated as authorized but unissued shares. For the six months ended June 30, 2014, we did not repurchase any shares under our Repurchase Program. At June 30, 2014, there were 1,493 remaining shares authorized for repurchase under our Repurchase Program.
Revenue Recognition	'
	Revenue Recognition
	Interest income is earned and recognized on Agency Securities based on their unpaid principal balance and their contractual terms. Premiums and discounts associated with the purchase of Agency Securities are amortized or accreted into interest income over the actual lives of the securities, reflecting actual prepayments as they occur.
	Interest income on Non-Agency Securities is recognized using the effective yield method over the life of the securities based on the future cash flows expected to be received. Future cash flow projections and related effective yields are determined for each security and updated quarterly. Other than temporary impairments, which establish a new cost basis in the security for purposes of calculating effective yields, are recognized when the fair value of a security is less than its cost basis and there has been an adverse change in the future cash flows expected to be received. Other changes in future cash flows expected to be received are recognized prospectively over the remaining life of the security.
Comprehensive Loss	'
	Comprehensive Income (Loss)
	Comprehensive income (loss) refers to changes in equity during a period from transactions and other events and circumstances from non-owner sources. It includes all changes in equity during a period, except those resulting from investments by owners and distributions to owners.

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following tables provide a summary of our assets that are measured at fair value on a recurring basis at June 30, 2014 and December 31, 2013.
		Quoted				Significant Observable				Significant Unobservable				Balance at June 30, 2014
		Prices in				Inputs				Inputs
		Active				(Level 2)				(Level 3)
		Markets for Identical
		Assets
		(Level 1)
	Assets at Fair Value:
	Agency Securities, available for sale	$	—			$	1,196,872			$	—			$	1,196,872
	Non-Agency Securities, trading	$	—			$	—			$	155,783			$	155,783
	Linked Transactions, net	$	—			$	—			$	14,448			$	14,448
	Derivatives	$	—			$	25,474			$	—			$	25,474
	There were no transfers of assets or liabilities between levels of the fair value hierarchy during the quarter and six months ended June 30, 2014.
		Quoted				Significant Observable				Significant Unobservable				Balance at December 31, 2013
		Prices in				Inputs				Inputs
		Active				(Level 2)				(Level 3)
		Markets for Identical
		Assets
		(Level 1)
	Assets at Fair Value:
	Agency Securities, available for sale	$	—			$	801,777			$	—			$	801,777
	Non-Agency Securities, trading	$	—			$	—			$	143,399			$	143,399
	Linked Transactions, net	$	—			$	—			$	16,322			$	16,322
	Derivatives	$	—			$	59,703			$	—			$	59,703
Carrying Values and Fair Values of Financial Assets and Liabilities	'
	The following tables provide a summary of the carrying values and fair values of our financial assets and liabilities not carried at fair value but for which fair value is required to be disclosed at June 30, 2014 and December 31, 2013.
		30-Jun-14								Fair Value Measurements using:
		Carrying				Fair				Quoted Prices				Significant Observable				Significant Unobservable
		Value				Value				in Active				Inputs				Inputs
										Markets for Identical				(Level 2)				(Level 3)
										Assets
										(Level 1)
	Financial Assets:
	Cash	$	22,397			$	22,397			$	22,397			$	—			$	—
	Cash collateral posted to counterparties	$	462			$	462			$	—			$	462			$	—
	Accrued interest receivable	$	3,072			$	3,072			$	—			$	3,072			$	—
	Financial Liabilities:
	Repurchase agreements	$	1,233,195			$	1,233,195			$	—			$	1,233,195			$	—
	Cash collateral posted by counterparties	$	23,766			$	23,766			$	—			$	23,766			$	—
	Accrued interest payable	$	819			$	819			$	—			$	819			$	—
		31-Dec-13								Fair Value Measurements using:
		Carrying				Fair				Quoted Prices				Significant Observable				Significant Unobservable
		Value				Value				in Active				Inputs				Inputs
										Markets for Identical				(Level 2)				(Level 3)
										Assets
										(Level 1)
	Financial Assets:
	Cash	$	41,524			$	41,524			$	41,524			$	—			$	—
	Cash collateral posted to counterparties	$	648			$	648			$	—			$	648			$	—
	Accrued interest receivable	$	2,336			$	2,336			$	—			$	2,336			$	—
	Financial Liabilities:
	Repurchase agreements	$	839,405			$	839,405			$	—			$	839,405			$	—
	Cash collateral posted by counterparties	$	53,314			$	53,314			$	—			$	53,314			$	—
	Accrued interest payable	$	611			$	611			$	—			$	611			$	—
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	'
	The following tables provide a summary of the changes in Level 3 assets measured at fair value on a recurring basis for the quarter and six months ended June 30, 2014 and June 30, 2013.
	Non-Agency Securities		For the Quarter Ended								For the Six Months Ended
			30-Jun-14				30-Jun-13				30-Jun-14				30-Jun-13
	Balance, beginning of period		$	142,409			$	136,752			$	143,399			$	129,946
	Purchase of Non-Agency Securities, at cost		16,735				23,518				17,985				33,275
	Principal repayments of Non-Agency Securities		(3,648		)		(5,371		)		(7,048		)		(10,246		)
	Gain (loss) on Non-Agency Securities		288				(5,635		)		1,121				(3,426		)
	Net change in discount on Non-Agency Securities		(1		)		(311		)		326				(596		)
	Balance, end of period		$	155,783			$	148,953			$	155,783			$	148,953
	Gain (loss) on Non-Agency Securities		$	288			$	(5,635	)		$	1,121			$	(3,426	)
	Linked Transactions		For the Quarter Ended								For the Six Months Ended
			30-Jun-14				30-Jun-13				30-Jun-14				30-Jun-13
	Balance, beginning of period		$	20,069			$	—			$	16,322			$	—
	Linked Transaction value of purchased Non-Agency Securities		(5,965		)		—				(5,965		)		—
	Cash (receipts) disbursements on Linked Transactions		(2,606		)		11,015				(3,369		)		11,015
	Unrealized net gain (loss) and net interest income from Linked Transactions		2,950				(2,288		)		7,460				(2,288		)
	Balance, end of period		$	14,448			$	8,727			$	14,448			$	8,727
	Gains (losses) on Linked Transactions		$	2,950			$	(2,288	)		$	7,460			$	(2,288	)
Range of Estimates of Cumulative Default and Loss Severities and Discount Rates	'
	The following tables present the range of our estimates of cumulative default and loss severities, together with the discount rates implicit in our Level 3 Non-Agency Security fair values (inclusive of Non-Agency Securities underlying Linked Transactions) at June 30, 2014 and December 31, 2013. See Note 8, "Linked Transactions" for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions.
	June 30, 2014
	Unobservable	Minimum			Weighted			Maximum
	Level 3 Input				Average
	Cumulative default	0	%		9.05	%		30.05	%
	Loss severity (life)	4.8	%		35.16	%		73.1	%
	Discount rate	2.59	%		4.7	%		6.5	%
	Delinquency (life)	0.4	%		9.52	%		38.6	%
	Voluntary prepayments (life)	7	%		9.08	%		12.7	%
	December 31, 2013
	Unobservable	Minimum			Weighted			Maximum
	Level 3 Input				Average
	Cumulative default	0	%		6.99	%		33.27	%
	Loss severity (life)	0	%		31.2	%		62.6	%
	Discount rate	4.01	%		5.32	%		6.5	%
	Delinquency (life)	0	%		9.74	%		29.5	%
	Voluntary prepayments (life)	6.7	%		9.74	%		14.8	%

Agency_Securities_Available_fo1

Agency Securities, Available for Sale (Tables) (Agency Securities)	6 Months Ended
	Jun. 30, 2014
Agency Securities	'
Schedule of Available-for-sale Securities [Line Items]	'
Available-for-sale Securities	'
	As of December 31, 2013, we had the following securities in an unrealized gain or loss position as presented below. The components of the carrying value of our Agency Securities as of December 31, 2013 are also presented below. All of our Agency Securities were fixed rate securities with a weighted average coupon of 3.48% as of December 31, 2013.
	December 31, 2013
		Amortized Cost		Gross Unrealized Loss			Gross Unrealized Gain		Fair Value			Percent of Total
	Fannie Mae
	15 Year Fixed	$	29,336	$	(1,057	)	$	—	$	28,279		3.53	%
	20 Year Fixed	30,974		(2,086		)	—		28,888			3.6	%
	25 Year Fixed	52,944		—			—		52,944			6.6	%
	30 Year Fixed	691,666		—			—		691,666			86.27	%
	Total Fannie Mae	$	804,920	$	(3,143	)	$	—	$	801,777		100	%
	Total Agency Securities	$	804,920	$	(3,143	)	$	—	$	801,777
	At June 30, 2014, we had the following securities in an unrealized gain or loss position as presented below. The components of the carrying value of our Agency Securities at June 30, 2014 are also presented below. All of our Agency Securities are fixed rate securities with a weighted average coupon of 3.23% at June 30, 2014.
	June 30, 2014
		Amortized Cost		Gross Unrealized Loss			Gross Unrealized Gain		Fair Value			Percent of Total
	Fannie Mae
	Multi-Family MBS	$	55,043	$	(37	)	$	839	$	55,845		4.7	%
	15 Year Fixed	1,085,631		(489		)	8,115		1,093,257			91.3	%
	20 Year Fixed	48,522		(1,031		)	279		47,770			4	%
	Total Fannie Mae	$	1,189,196	$	(1,557	)	$	9,233	$	1,196,872		100	%
	Total Agency Securities	$	1,189,196	$	(1,557	)	$	9,233	$	1,196,872
Investments Classified by Contractual Maturity Date	'
	The following table summarizes the weighted average lives of our Agency Securities at June 30, 2014 and December 31, 2013.
		June 30, 2014					December 31, 2013
	Weighted Average Life of all Agency Securities	Fair Value		Amortized			Fair Value		Amortized
				Cost					Cost
	Less than one year	$	—	$	—		$	—	$	—
	Greater than or equal to one year and less than three years	57,314		56,944			—		—
	Greater than or equal to three years and less than five years	1,059,441		1,051,998			28,279		29,336
	Greater than or equal to five years	80,117		80,254			773,498		775,584
	Total Agency Securities	$	1,196,872	$	1,189,196		$	801,777	$	804,920
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	'
	The following table presents the unrealized losses and estimated fair value of our Agency Securities by length of time that such securities have been in a continuous unrealized loss position at June 30, 2014 and December 31, 2013.
		Unrealized Loss Position For:
		Less than 12 Months					12 Months or More						Total
	As of	Fair Value		Unrealized			Fair Value		Unrealized				Fair Value		Unrealized
				Losses					Losses						Losses
	June 30, 2014	$	5,018	$	(37	)	$	54,139	$	(1,520	)		$	59,157	$	(1,557	)
	December 31, 2013	$	—	$	—		$	57,167	$	(3,143	)		$	57,167	$	(3,143	)

NonAgency_Securities_Trading_T

Non-Agency Securities, Trading (Tables) (Non-Agency Securities)	6 Months Ended
	Jun. 30, 2014
Non-Agency Securities	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'
Trading Securities	'
	At June 30, 2014, investments in Non-Agency Securities accounted for 11.5% of our MBS portfolio and 19.1% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8,“Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
		Non-Agency Securities
	June 30, 2014	Fair Value		Amortized			Principal		Weighted
				Cost			Amount		Average
									Coupon
	Prime Fixed	$	53,761	$	53,303		$	60,687	5	%
	Prime Hybrid	16,202		14,745			19,840		3.02	%
	Prime Floater	3,840		3,261			3,250		5.12	%
	Alt-A Fixed	73,185		69,997			88,469		5.87	%
	Alt-A Hybrid	8,795		8,231			10,473		2.48	%
	Total Non-Agency Securities	$	155,783	$	149,537		$	182,719	5.07	%
	At December 31, 2013, investments in Non-Agency Securities accounted for 15.2% of our total MBS portfolio and 26.2% of our total MBS portfolio inclusive of the Non-Agency Securities underlying our Linked Transactions (see Note 8,“Linked Transactions” for additional discussion of Non-Agency Securities that are accounted for as a component of Linked Transactions).
		Non-Agency Securities
	December 31, 2013	Fair Value		Amortized			Principal		Weighted
				Cost			Amount		Average
									Coupon
	Prime Fixed	$	51,515	$	51,922		$	57,995	4.96	%
	Prime Hybrid	17,067		15,705			21,253		3.36	%
	Prime Floater	2,117		2,001			2,000		5.41	%
	Alt-A Fixed	63,582		61,554			77,922		5.85	%
	Alt-A Hybrid	9,118		8,494			11,091		2.59	%
	Total Non-Agency Securities	$	143,399	$	139,676		$	170,261	5.02	%
Investments Classified by Contractual Maturity Date	'
	The following table summarizes the weighted average lives of our Non-Agency Securities at June 30, 2014 and December 31, 2013.
		June 30, 2014					December 31, 2013
	Weighted Average Life of all Non-Agency Securities	Fair Value		Amortized			Fair Value		Amortized
				Cost					Cost
	Less than one year	$	—	$	—		$	—	$	—
	Greater than or equal to one year and less than three years	—		—			—		—
	Greater than or equal to three years and less than five years	4,724		4,641			36,581		35,254
	Greater than or equal to five years	151,059		144,896			106,818		104,422
	Total Non-Agency Securities	$	155,783	$	149,537		$	143,399	$	139,676
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	'
	The following table presents the unrealized losses and estimated fair value of our Non-Agency Securities by length of time that such securities have been in a continuous unrealized loss position at June 30, 2014 and December 31, 2013.
		Unrealized Loss Position For:
		Less than 12 months					12 Months or More					Total
	As of	Fair Value		Unrealized			Fair Value		Unrealized			Fair Value		Unrealized
				Losses					Losses					Losses
	June 30, 2014	$	2,703	$	(168	)	$	5,978	$	(328	)	$	8,681	$	(496	)
	December 31, 2013	$	42,096	$	(1,089	)	$	—	$	—		$	42,096	$	(1,089	)

Linked_Transactions_Tables

Linked Transactions (Tables)	6 Months Ended
	Jun. 30, 2014
Linked Transactions Disclosure [Abstract]	'
Non-Agency Securities and Repurchase Agreements Underlying Linked Transactions	'
	The following tables present information about our Non-Agency Securities and repurchase agreements underlying our Linked Transactions at June 30, 2014 and December 31, 2013. Our Non-Agency Securities underlying our Linked Transactions represent approximately 8.54% and 13.0% of our overall investment in MBS at June 30, 2014 and December 31, 2013, respectively.
	June 30, 2014
	Linked Repurchase Agreements							Linked Non-Agency Securities
	Maturity or Repricing	Balance			Weighted Average Interest Rate			Non-Agency MBS		Fair Value			Amortized		Par/Current		Weighted Average Coupon
													Cost		Face		Rate
	Within 30 days	$	5,072		1.91	%		Prime		$	110,846		$	109,709	$	114,306	3.11	%
	31 days to 60 days	36,605			1.03	%		Alt-A		15,404			14,760		19,190		6.05	%
	61 days to 90 days	63,752			0.98	%		Total		$	126,250		$	124,469	$	133,496	3.47	%
	Greater than 90 days	6,310			2.03	%
	Total	$	111,739		1.1	%
	December 31, 2013
	Linked Repurchase Agreements							Linked Non-Agency Securities
	Maturity or Repricing	Balance			Weighted Average Interest Rate			Non-Agency MBS		Fair Value			Amortized Cost		Par/Current Face		Weighted Average Coupon Rate
	Within 30 days	$	8,177		1.88	%		Prime		$	112,956		$	116,631	$	121,571	3	%
	31 days to 60 days	44,974			1.23	%		Alt-A		27,989			27,788		35,822		4.71	%
	61 days to 90 days	71,389			1.09	%		Total		$	140,945		$	144,419	$	157,393	3.34	%
	Greater than 90 days	—			0	%
	Total	$	124,540		1.19	%
Schedule of Other Nonoperating Income (Expense)	'
	The following table presents certain information about the components of the unrealized net gains and net interest income from Linked Transactions included in our condensed consolidated statements of operations for the quarter and six months ended June 30, 2014 and June 30, 2013.
		For the Quarter Ended							For the Six Months Ended
	Unrealized Net Gain and Net Interest Income from Linked Transactions	30-Jun-14			30-Jun-13				30-Jun-14			30-Jun-13
	Interest income attributable to MBS underlying Linked Transactions	$	1,300		$	39			$	2,869		$	39
	Interest expense attributable to linked repurchase agreements underlying Linked Transactions	(161		)	(915		)		(450		)	(915		)
	Change in fair value of Linked Transactions included in earnings	1,811			(1,412		)		5,041			(1,412		)
	Unrealized net gain (loss) and net interest income (loss) from Linked Transactions	$	2,950		$	(2,288	)		$	7,460		$	(2,288	)

Repurchase_Agreements_Tables

Repurchase Agreements (Tables)	6 Months Ended
	Jun. 30, 2014
Disclosure of Repurchase Agreements [Abstract]	'
Schedule of Repurchase Agreements	'
	The following tables represent the contractual repricing and other information regarding our repurchase agreements to finance our MBS purchases at June 30, 2014 and December 31, 2013.
	30-Jun-14	Repurchase Agreements		Weighted		Weighted		Haircut for
				Average		Average		Repurchase Agreements (1)
				Contractual		Maturity
				Rate		in days
	Agency Securities	$	1,126,421	0.34	%	39		4.79	%
	Non-Agency Securities	106,774		1.95	%	242		24.46	%
	Total or Weighted Average	$	1,233,195	0.48	%	57		6.49	%
	(1) The Haircut represents the weighted average margin requirement, or the percentage amount by which the collateral value must exceed the loan amount.
	31-Dec-13	Repurchase Agreements		Weighted		Weighted		Haircut for
				Average		Average		Repurchase Agreements (1)
				Contractual Rate		Maturity in
						days
	Agency Securities	$	731,782	0.42	%	33		4.9	%
	Non-Agency Securities	107,623		1.96	%	46		25.39	%
	Total or Weighted Average	$	839,405	0.61	%	35		7.53	%
	(1) The Haircut represents the weighted average margin requirement, or the percentage amount by which the collateral value must exceed the loan amount.
		30-Jun-14				31-Dec-13
	Maturing or Repricing	Repurchase Agreements		Weighted		Repurchase Agreements				Weighted
				Average						Average
				Contractual Rate						Contractual Rate
	Within 30 days	$	657,358	0.47	%	$	380,744			0.67	%
	31 days to 60 days	288,287		0.39	%	408,054				0.49	%
	61 days to 90 days	165,429		0.46	%	40,362				1	%
	Greater than 90 days	122,121		0.81	%	10,245				2.1	%
	Total or Weighted Average	$	1,233,195	0.48	%	$	839,405			0.61	%

Derivatives_Tables

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments	'
	December 31, 2013
	Derivative Type		Remaining / Underlying Term		Weighted Average Remaining Swap / Option Term (Months)		Weighted Average Rate			Notional Amount				Asset Fair Value (1)				Liability Fair Value (1)
	Interest rate swap contracts		0-12 Months		0		0	%		$	—			$	—			$	—
	Interest rate swap contracts		13-24 Months		0		0	%		—				—				—
	Interest rate swap contracts		25-36 Months		0		0	%		—				—				—
	Interest rate swap contracts		37-48 Months		46		0.55	%		50,000				801				—
	Interest rate swap contracts		49-60 Months		53		0.92	%		50,000				532				—
	Interest rate swap contracts		61-72 Months		0		0	%		—				—				—
	Interest rate swap contracts		73-84 Months		0		0	%		—				—				—
	Interest rate swap contracts		85-96 Months		0		0	%		—				—				—
	Interest rate swap contracts		97-108 Months		105		1.5	%		175,000				15,023				—
	Interest rate swap contracts		109-120 Months		112		1.91	%		526,250				36,463				—
	Interest rate swaptions		60 Months		9		2.73	%		750,000				6,884				—
	Total or Weighted Average				58		2.19	%		$	1,551,250			$	59,703			$	—
	-1	See Note 5, “Fair Value of Financial Instruments” for additional discussion.
	The following tables present information about interest rate swap contracts and interest rate swaptions which are included in derivatives on the accompanying condensed consolidated balance sheets as of June 30, 2014 and December 31, 2013.
	June 30, 2014
	Derivative Type		Remaining / Underlying Term		Weighted Average Remaining Swap / Option Term (Months)		Weighted Average Rate			Notional Amount				Asset Fair Value (1)				Liability Fair Value (1)
	Interest rate swap contracts		0-12 Months		0		0	%		$	—			$	—			$	—
	Interest rate swap contracts		13-24 Months		0		0	%		—				—				—
	Interest rate swap contracts		25-36 Months		0		0	%		—				—				—
	Interest rate swap contract		37-48 Months		43		0.73	%		100,000				950				—
	Interest rate swap contracts		49-60 Months		0		0	%		—				—				—
	Interest rate swap contracts		61-72 Months		0		0	%		—				—				—
	Interest rate swap contracts		73-84 Months		0		0	%		—				—				—
	Interest rate swap contracts		85-96 Months		0		0	%		—				—				—
	Interest rate swap contracts		97-108 Months		104		1.76	%		601,250				20,703				—
	Interest rate swap contracts		109-120 Months		112		2.05	%		100,000				3,658				—
	Interest rate swaptions		60 Months		3		2.73	%		750,000				163				—
	Total or Weighted Average				52		2.19	%		$	1,551,250			$	25,474			$	—
	-1	See Note 5, “Fair Value of Financial Instruments” for additional discussion.
Potential Effects of Netting Derivative Instruments on the Balance Sheets	'
	The following tables present information about interest rate swap contracts and interest rate swaptions and the potential effects of netting if we were to offset the assets and liabilities of these financial instruments on the accompanying balance sheets. Currently, we present these financial instruments at their gross amounts and they are included in derivatives, at fair value on the accompanying condensed consolidated balance sheet as of December 31, 2013.
	December 31, 2013						Gross Amounts Not Offset in the
							Condensed Consolidated Balance Sheet
	Assets		Gross and Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet				Financial Instruments				Cash Collateral				Net Amount
	Interest rate swap contracts		$	52,819			$	—			$	(52,315	)		$	504
	Interest rate swaptions		6,884				—				—				$	6,884
	Totals		$	59,703			$	—			$	(52,315	)		$	7,388
	The following tables present information about interest rate swap contracts and interest rate swaptions and the potential effects of the master netting arrangements if we were to offset the assets and liabilities of these financial instruments on the accompanying balance sheets. Currently, we present these financial instruments at their gross amounts and they are included in derivatives at fair value on the accompanying condensed consolidated balance sheet as of June 30, 2014.
	30-Jun-14						Gross Amounts Not Offset
							in the
							Condensed Consolidated Balance Sheet
	Assets		Gross and Net Amounts				Financial				Cash				Net Amount
			of Assets				Instruments				Collateral
			Presented in the Condensed Consolidated
			Balance Sheet
	Interest rate swap contracts		$	25,311			$	—			$	(23,290	)		$	2,021
	Interest rate swaptions		163				—				—				163
	Totals		$	25,474			$	—			$	(23,290	)		$	2,184
Derivative Instruments, Gain (Loss)	'
	The following table represents the location and information regarding our derivatives which are included in total Other Income (Loss) in the accompanying condensed consolidated statements of operations for the quarter and six months ended June 30, 2014 and June 30, 2013.
					Income (Loss) Recognized
					For the Quarter Ended								For the Six Months Ended
	Derivatives		Location on condensed consolidated statements of operations		30-Jun-14				30-Jun-13				30-Jun-14				30-Jun-13
	Interest rate swap contracts:
	Interest income		Realized loss on derivatives		$	263			$	204			$	503			$	317
	Interest expense		Realized loss on derivatives		(3,360		)		(2,193		)		(6,706		)		(3,256		)
	Changes in fair value		Unrealized gain (loss) on derivatives		(13,142		)		36,970				(29,011		)		40,086
					$	(16,239	)		$	34,981			$	(35,214	)		$	37,147
	Interest rate swaptions:
	Changes in fair value		Unrealized gain (loss) on derivatives		(2,561		)		6,211				(6,721		)		6,540
					$	(2,561	)		$	6,211			$	(6,721	)		$	6,540
	Totals				$	(18,800	)		$	41,192			$	(41,935	)		$	43,687

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Dividends Transactions	'
	The following table presents our common stock dividend transactions for the six months ended June 30, 2014.
	Record Date	Payment Date	Rate per		Aggregate
			common share		amount paid to
					holders of record
	15-Jan-14	30-Jan-14	$	0.15	$	1,799
	14-Feb-14	27-Feb-14	$	0.15	$	1,799
	17-Mar-14	28-Mar-14	$	0.15	$	1,799
	15-Apr-14	29-Apr-14	$	0.15	$	1,799
	15-May-14	29-May-14	$	0.15	$	1,799
	16-Jun-14	27-Jun-14	$	0.15	$	1,800
	Total dividends paid				$	10,795

Income_Taxes_Tables

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2014
Income Tax Disclosure [Abstract]	'
Schedule of Effective Income Tax Rate Reconciliation	'
	The following table reconciles our GAAP net income (loss) to estimated REIT taxable income for the quarter and six months ended June 30, 2014 and June 30, 2013.
		For the Quarter Ended						For the Six Months Ended
		30-Jun-14			30-Jun-13			30-Jun-14			30-Jun-13
	GAAP net income (loss)	$	(8,776	)	$	38,237		$	(10,639	)	$	49,213
	Book to tax differences:
	Net book to tax differences on Non-Agency Securities and Linked Transactions	(2,003		)	8,359			(5,699		)	6,634
	Unrealized loss on U.S. Treasury Securities sold short	—			2,716			—			2,716
	Realized capital loss on short sale of U.S. Treasury Securities	—			390			—			390
	(Gain) loss on sale of Agency Securities	34			—			(8,776		)	—
	Amortization of deferred hedging gains	146			—			291			—
	Net premium amortization differences	(181		)	—			(809		)	—
	Changes in interest rate contracts	15,703			(43,181		)	35,732			(46,626		)
	Other	(6		)	—			(5		)	2
	Estimated taxable income	$	4,917		$	6,521		$	10,095		$	12,329

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	Jun. 30, 2014	Mar. 05, 2014	Dec. 31, 2013	Oct. 30, 2013
In Thousands, except Share data, unless otherwise specified
Accounting Policies [Abstract]	'	'	'	'
Preferred stock, shares authorized (in Shares)	25,000,000	'	25,000,000	'
Preferred stock, par value (in usd per share)	$0.00	'	$0.00	'
Common stock, shares authorized (in Shares)	250,000,000	'	250,000,000	'
Common stock, par value (in Dollars per share)	$0.00	'	$0.00	'
Common stock, shares issued (in Shares)	11,999,000	'	11,993,000	'
Common stock, shares outstanding (in Shares)	11,999,000	'	11,993,000	'
Number of shares authorized to be repurchased	'	3,000,000	'	2,000,000
Remaining authorized repurchase amount	$1,493	'	'	'

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details)	6 Months Ended
	Jun. 30, 2014
	dealer
Fair Value Disclosures [Abstract]	'
Number of dealers received quotes from	3

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments (Details) - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Assets at Fair Value:	'		'
Agency Securities, available for sale	$1,196,872		$801,777
Non-Agency Securities, trading	155,783		143,399
Linked Transactions, net	14,448		16,322
Derivatives, at fair value	25,474	[1]	59,703	[1]
Significant Observable Inputs (Level 2)	'		'
Assets at Fair Value:	'		'
Agency Securities, available for sale	1,196,872		801,777
Linked Transactions, net	0		'
Derivatives, at fair value	25,474		59,703
Significant Unobservable Inputs (Level 3)	'		'
Assets at Fair Value:	'		'
Non-Agency Securities, trading	155,783		143,399
Linked Transactions, net	$14,448		$16,322
[1]	See Note 5, “Fair Value of Financial Instruments” for additional discussion.

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments (Details) - Carrying Values and Fair Values of Financial Assets and Liabilities (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financial Assets:	'	'	'	'
Cash, carrying value	$22,397	$41,524	$47,938	$36,316
Cash, fair value	22,397	41,524	'	'
Cash collateral posted, carrying value	462	648	'	'
Cash collateral posted, fair value	462	648	'	'
Accrued interest receivable, carrying value	3,072	2,336	'	'
Accrued interest receivable, fair value	3,072	2,336	'	'
Financial Liabilities:	'	'	'	'
Repurchase agreements, carrying value	1,233,195	839,405	'	'
Repurchase agreements, fair value	1,233,195	839,405	'	'
Cash collateral held, carrying value	23,766	53,314	'	'
Cash collateral held, fair value	23,766	53,314	'	'
Accrued interest payable, carrying value	819	611	'	'
Accrued interest payable, fair value	819	611	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1)	'	'	'	'
Financial Assets:	'	'	'	'
Cash, fair value	22,397	41,524	'	'
Significant Observable Inputs (Level 2)	'	'	'	'
Financial Assets:	'	'	'	'
Cash collateral posted, fair value	462	648	'	'
Accrued interest receivable, fair value	3,072	2,336	'	'
Financial Liabilities:	'	'	'	'
Repurchase agreements, fair value	1,233,195	839,405	'	'
Cash collateral held, fair value	23,766	53,314	'	'
Accrued interest payable, fair value	$819	$611	'	'

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments (Details) - Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis, Trading Securities (Trading Securities, Significant Unobservable Inputs (Level 3), USD $)	3 Months Ended		6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Dec. 31, 2013
Trading Securities | Significant Unobservable Inputs (Level 3)	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Balance, beginning of period	$142,409	$136,752	$143,399	$129,946
Purchase of Non-Agency Securities, at cost	16,735	23,518	17,985	33,275
Principal repayments of Non-Agency Securities	-3,648	-5,371	-7,048	-10,246
Gain (loss) on Non-Agency Securities	288	-5,635	1,121	-3,426
Net change in discount on Non-Agency Securities	-1	-311	326	-596
Balance, end of period	155,783	148,953	155,783	143,399
Gain (loss) on Non-Agency Securities	$288	($5,635)	$1,121	($3,426)

Fair_Value_of_Financial_Instru6

Fair Value of Financial Instruments Fair Value of Financial Instruments (Details) - Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis, Linked Transactions (USD $)	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Dec. 31, 2013
					Linked Transactions	Linked Transactions	Linked Transactions	Linked Transactions
					Significant Unobservable Inputs (Level 3)	Significant Unobservable Inputs (Level 3)	Significant Unobservable Inputs (Level 3)	Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	'	$20,069	$0	$16,322	$0
Linked Transaction value of purchased Non-Agency Securities	'	'	'	'	-5,965	0	-5,965	0
Cash (receipts) disbursements on Linked Transactions	'	'	'	'	-2,606	11,015	-3,369	11,015
Unrealized net gain (loss) and net interest income from Linked Transactions	'	'	'	'	2,950	-2,288	7,460	-2,288
Balance, end of period	'	'	'	'	14,448	8,727	14,448	16,322
Gains (losses) on Linked Transactions	$2,950	($2,288)	$7,460	($2,288)	$2,950	($2,288)	$7,460	($2,288)

Fair_Value_of_Financial_Instru7

Fair Value of Financial Instruments (Details) - Range of Estimates of Cumulative Default and Loss Severities and Discount Rates	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Minimum	'	'
Fair Value Inputs, Equity, Quantitative Information [Line Items]	'	'
Cumulative default	0.00%	0.00%
Loss severity (life)	4.80%	0.00%
Discount rate	2.59%	4.01%
Delinquency (life)	0.40%	0.00%
Voluntary prepayments (life)	7.00%	6.70%
Weighted Average	'	'
Fair Value Inputs, Equity, Quantitative Information [Line Items]	'	'
Cumulative default	9.05%	6.99%
Loss severity (life)	35.16%	31.20%
Discount rate	4.70%	5.32%
Delinquency (life)	9.52%	9.74%
Voluntary prepayments (life)	9.08%	9.74%
Maximum	'	'
Fair Value Inputs, Equity, Quantitative Information [Line Items]	'	'
Cumulative default	30.05%	33.27%
Loss severity (life)	73.10%	62.60%
Discount rate	6.50%	6.50%
Delinquency (life)	38.60%	29.50%
Voluntary prepayments (life)	12.70%	14.80%

Agency_Securities_Available_fo2

Agency Securities, Available for Sale (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'
Other than temporary impairment loss	$44,300,000	'	'	'	'
Fair Value	801,777,000	1,196,872,000	'	1,196,872,000	'
Weighted average coupon	3.48%	3.23%	'	3.23%	'
Sale proceeds (in dollars)	'	0	0	743,647,000	0
Realized gain (loss) on sale of Agency Securities (reclassified from Other comprehensive income (loss))	'	-34,000	0	8,776,000	0
MBS Portfolio	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'
Percentage of Portfolio Invested in Agency Securities	84.80%	88.50%	'	88.50%	'
MBS Portfolio Inclusive of Non-Agency Securities Underlying Linked Transactions	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'
Percentage of Portfolio Invested in Agency Securities	73.80%	80.90%	'	80.90%	'
25-Year and 30-Year Fixed Rate Agency Securities	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'
Fair Value	$744,600,000	'	'	'	'

Agency_Securities_Available_fo3

Agency Securities, Available for Sale (Details) - Unrealized Gain or Loss Position and Components of Carrying Value of Available for Sale Agency Securities (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$1,189,196,000	$804,920,000
Gross Unrealized Loss	-1,557,000	-3,143,000
Gross Unrealized Gain	9,233,000	0
Fair Value	1,196,872,000	801,777,000
Fannie Mae	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,189,196,000	804,920,000
Gross Unrealized Loss	-1,557,000	-3,143,000
Gross Unrealized Gain	9,233,000	0
Fair Value	1,196,872,000	801,777,000
Percent of Total	100.00%	100.00%
Fannie Mae | Multi-Family MBS	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	55,043,000	'
Gross Unrealized Loss	-37,000	'
Gross Unrealized Gain	839,000	'
Fair Value	55,845,000	'
Percent of Total	4.70%	'
Fannie Mae | 15 Year Fixed	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,085,631,000	29,336,000
Gross Unrealized Loss	-489,000	-1,057,000
Gross Unrealized Gain	8,115,000	0
Fair Value	1,093,257,000	28,279,000
Percent of Total	91.30%	3.53%
Fannie Mae | 20 Year Fixed	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	48,522,000	30,974,000
Gross Unrealized Loss	-1,031,000	-2,086,000
Gross Unrealized Gain	279,000	0
Fair Value	47,770,000	28,888,000
Percent of Total	4.00%	3.60%
Fannie Mae | 25 Year Fixed	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	'	52,944,000
Gross Unrealized Loss	'	0
Gross Unrealized Gain	'	0
Fair Value	'	52,944,000
Percent of Total	'	6.60%
Fannie Mae | 30 Year Fixed	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	'	691,666,000
Gross Unrealized Loss	'	0
Gross Unrealized Gain	'	0
Fair Value	'	$691,666,000
Percent of Total	'	86.27%

Agency_Securities_Available_fo4

Agency Securities, Available for Sale (Details) - Summary of Weighted Average Lives of Agency Securities (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value	'	'
Greater than or equal to one year and less than three years	$57,314	$0
Greater than or equal to three years and less than five years	1,059,441	28,279
Greater than or equal to five years	80,117	773,498
Total Agency Securities	1,196,872	801,777
Amortized Cost	'	'
Greater than or equal to one year and less than three years	56,944	0
Greater than or equal to three years and less than five years	1,051,998	29,336
Greater than or equal to five years	80,254	775,584
Total Agency Securities	$1,189,196	$804,920

Agency_Securities_Available_fo5

Agency Securities, Available for Sale (Details) - Unrealized Losses and Estimated Fair Value of Agency Securities (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value	'	'
Less than 12 Months	$5,018	$0
12 Months or More	54,139	57,167
Total	59,157	57,167
Unrealized Losses	'	'
Less than 12 Months	-37	0
12 Months or More	-1,520	-3,143
Total	($1,557)	($3,143)

NonAgency_Securities_Trading_D

Non-Agency Securities, Trading (Details) (USD $)	1 Months Ended	3 Months Ended
	Apr. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
US treasury securities received in year one and two	$50,000,000	'	'
US treasury securities received in year three	30,000,000	'	'
Payments for non agency securities	'	16,735,000	'
Trading Securities, Debt	'	155,783,000	143,399,000
Securities pledged as collateral	'	-47,721,000	'
US treasury securities received as collateral	'	12,153,000	'
Proceeds from repurchase agreement borrowings used to purchase trading securities	'	10,770,000	'
MBS Portfolio	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Percentage of Portfolio Invested in Non-Agency Securities	'	11.50%	15.20%
Overall Investment in Non-Agency Securities Including Those Underlying Linked Transactions	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Percentage of Portfolio Invested in Non-Agency Securities	'	19.10%	26.20%
Securities Sold under Agreements to Repurchase	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Cash received as collateral	'	$22,483,000	'

NonAgency_Securities_Trading_D1

Non-Agency Securities, Trading (Details) - Non-Agency Securities (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Fair Value	$155,783	$143,399
Amortized Cost	149,537	139,676
Principal Amount	182,719	170,261
Weighted Average Coupon	5.07%	5.02%
Prime Fixed	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Fair Value	53,761	51,515
Amortized Cost	53,303	51,922
Principal Amount	60,687	57,995
Weighted Average Coupon	5.00%	4.96%
Prime Hybrid	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Fair Value	16,202	17,067
Amortized Cost	14,745	15,705
Principal Amount	19,840	21,253
Weighted Average Coupon	3.02%	3.36%
Prime Floater	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Fair Value	3,840	2,117
Amortized Cost	3,261	2,001
Principal Amount	3,250	2,000
Weighted Average Coupon	5.12%	5.41%
Alt-A Fixed	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Fair Value	73,185	63,582
Amortized Cost	69,997	61,554
Principal Amount	88,469	77,922
Weighted Average Coupon	5.87%	5.85%
Alt-A Hybrid	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Fair Value	8,795	9,118
Amortized Cost	8,231	8,494
Principal Amount	$10,473	$11,091
Weighted Average Coupon	2.48%	2.59%

NonAgency_Securities_Trading_D2

Non-Agency Securities, Trading (Details) - Summary of Weighted Average Lives of Non-Agency Securities (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value	'	'
Greater than or equal to three years and less than five years	$4,724	$36,581
Greater than or equal to five years	151,059	106,818
Total Non-Agency Securities	155,783	143,399
Amortized Cost	'	'
Greater than or equal to three years and less than five years	4,641	35,254
Greater than or equal to five years	144,896	104,422
Total Non-Agency Securities	$149,537	$139,676

NonAgency_Securities_Trading_D3

Non-Agency Securities, Trading (Details) - Unrealized Losses and Estimated Fair Value of Non-Agency Securities (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value	'	'
Less than 12 months	$5,018	$0
12 Months or More	54,139	57,167
Total	59,157	57,167
Unrealized Losses	'	'
Less than 12 months	-37	0
12 Months or More	-1,520	-3,143
Total	-1,557	-3,143
Non-Agency Securities	'	'
Fair Value	'	'
Less than 12 months	2,703	42,096
12 Months or More	5,978	0
Total	8,681	42,096
Unrealized Losses	'	'
Less than 12 months	-168	-1,089
12 Months or More	-328	0
Total	($496)	($1,089)

Linked_Transactions_Details

Linked Transactions (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Linked Transactions (Details) [Line Items]	'	'
Accrued interest payable	$819	$611
MBS Portfolio	'	'
Linked Transactions (Details) [Line Items]	'	'
Percentage of portfolio invested in non-agency securities underlying linked transactions	8.54%	13.00%
Linked Transactions	'	'
Linked Transactions (Details) [Line Items]	'	'
Accrued interest payable	$63	$83

Linked_Transactions_Details_No

Linked Transactions (Details) - Non-Agency Securities and Repurchase Agreements Underlying Linked Transactions (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Linked Repurchase Agreements	'	'
Balance	$1,233,195	$839,405
Weighted Average Interest Rate	0.48%	0.61%
Linked Non-Agency Securities	'	'
Fair Value	155,783	143,399
Amortized Cost	149,537	139,676
Par/Current Face	182,719	170,261
Weighted Average Coupon Rate	5.07%	5.02%
Linked Transactions	'	'
Linked Repurchase Agreements	'	'
Balance	111,739	124,540
Weighted Average Interest Rate	1.10%	1.19%
Within 30 Days | Linked Transactions	'	'
Linked Repurchase Agreements	'	'
Balance	5,072	8,177
Weighted Average Interest Rate	1.91%	1.88%
Linked Non-Agency Securities	'	'
Fair Value	110,846	112,956
Amortized Cost	109,709	116,631
Par/Current Face	114,306	121,571
Weighted Average Coupon Rate	3.11%	3.00%
From 31 to 60 Days | Linked Transactions	'	'
Linked Repurchase Agreements	'	'
Balance	36,605	44,974
Weighted Average Interest Rate	1.03%	1.23%
Linked Non-Agency Securities	'	'
Fair Value	15,404	27,989
Amortized Cost	14,760	27,788
Par/Current Face	19,190	35,822
Weighted Average Coupon Rate	6.05%	4.71%
From 61 to 90 Days | Linked Transactions	'	'
Linked Repurchase Agreements	'	'
Balance	63,752	71,389
Weighted Average Interest Rate	0.98%	1.09%
Linked Non-Agency Securities	'	'
Fair Value	126,250	140,945
Amortized Cost	124,469	144,419
Par/Current Face	133,496	157,393
Weighted Average Coupon Rate	3.47%	3.34%
Greater than 90 Days | Linked Transactions	'	'
Linked Repurchase Agreements	'	'
Balance	$6,310	$0
Weighted Average Interest Rate	2.03%	0.00%

Linked_Transactions_Details_Un

Linked Transactions (Details) - Unrealized Net Gain (Loss) and Net Interest Income from Linked Transactions (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Linked Transactions Disclosure [Abstract]	'	'	'	'
Interest income attributable to MBS underlying Linked Transactions	$1,300	$39	$2,869	$39
Interest expense attributable to linked repurchase agreements underlying Linked Transactions	-161	-915	-450	-915
Change in fair value of Linked Transactions included in earnings	1,811	-1,412	5,041	-1,412
Unrealized net gain (loss) and net interest income (loss) from Linked Transactions	$2,950	($2,288)	$7,460	($2,288)

Repurchase_Agreements_Details

Repurchase Agreements (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
	counterparty		counterparty		counterparty
Repurchase Agreement Counterparty [Line Items]	'	'	'	'	'
Number of counterparties	29	'	29	'	27
Securities Sold under Agreements to Repurchase	$1,233,195,000	'	$1,233,195,000	'	$839,405,000
Proceeds from short sales of U.S. treasury securities	0	301,903,000	0	301,903,000	'
Payments to acquire US treasury securities	0	70,126,000	0	70,126,000	'
Realized loss on short sale of U.S. Treasury Securities	0	-390,000	0	-390,000	'
Unrealized loss on sale of U.S. Treasury Securities sold short	$0	($2,716,000)	$0	($2,716,000)	'
Borrowings	'	'	'	'	'
Repurchase Agreement Counterparty [Line Items]	'	'	'	'	'
Number of counterparties	10	'	10	'	'
Repurchase Agreement Borrowings	'	'	'	'	'
Repurchase Agreement Counterparty [Line Items]	'	'	'	'	'
Percentage of concentration risk	'	'	68.50%	'	'
Minimum | Borrowings	'	'	'	'	'
Repurchase Agreement Counterparty [Line Items]	'	'	'	'	'
Percentage of concentration risk	'	'	5.00%	'	'
Maximum | Borrowings	'	'	'	'	'
Repurchase Agreement Counterparty [Line Items]	'	'	'	'	'
Percentage of concentration risk	'	'	10.00%	'	'
Outstanding Borrowings	'	'	'	'	'
Repurchase Agreement Counterparty [Line Items]	'	'	'	'	'
Number of counterparties	23	'	23	'	20

Repurchase_Agreements_Details_

Repurchase Agreements (Details) - Repurchase Agreements Information (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Assets Sold under Agreements to Repurchase [Line Items]	'		'
Repurchase Agreements	$1,233,195		$839,405
Weighted Average Contractual Rate	0.48%		0.61%
Weighted Average Maturity in days	'57 days		'35 days
Haircut for Repurchase Agreements	6.49%	[1]	7.53%	[1]
Agency Securities	'		'
Assets Sold under Agreements to Repurchase [Line Items]	'		'
Repurchase Agreements	1,126,421		731,782
Weighted Average Contractual Rate	0.34%		0.42%
Weighted Average Maturity in days	'39 days		'33 days
Haircut for Repurchase Agreements	4.79%	[1]	4.90%	[1]
Non-Agency Securities	'		'
Assets Sold under Agreements to Repurchase [Line Items]	'		'
Repurchase Agreements	$106,774		$107,623
Weighted Average Contractual Rate	1.95%		1.96%
Weighted Average Maturity in days	'242 days		'46 days
Haircut for Repurchase Agreements	24.46%	[1]	25.39%	[1]
[1]	The Haircut represents the weighted average margin requirement, or the percentage amount by which the collateral value must exceed the loan amount.

Repurchase_Agreements_Details_1

Repurchase Agreements (Details) - Repurchase Agreements Information - Additional (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Repurchase Agreements	$1,233,195	$839,405
Weighted Average Contractual Rate	0.48%	0.61%
Within 30 days	'	'
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Repurchase Agreements	657,358	380,744
Weighted Average Contractual Rate	0.47%	0.67%
31 days to 60 days	'	'
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Repurchase Agreements	288,287	408,054
Weighted Average Contractual Rate	0.39%	0.49%
61 days to 90 days	'	'
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Repurchase Agreements	165,429	40,362
Weighted Average Contractual Rate	0.46%	1.00%
Greater than 90 days	'	'
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Repurchase Agreements	$122,121	$10,245
Weighted Average Contractual Rate	0.81%	2.10%

Derivatives_Details_Interest_R

Derivatives (Details) - Interest Rate Swap Contracts and Interest Rate Swaptions (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2014		Dec. 31, 2013
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'52 days		'58 months
Weighted Average Rate	2.19%		2.19%
Notional Amount	$1,551,250,000		$1,551,250,000
Assets at Fair Value	25,474,000	[1]	59,703,000	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 0-12 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'0 months
Weighted Average Rate	0.00%		0.00%
Notional Amount	0		0
Assets at Fair Value	0	[1]	0	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 13-24 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'0 months
Weighted Average Rate	0.00%		0.00%
Notional Amount	0		0
Assets at Fair Value	0	[1]	0	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 25-36 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'0 months
Weighted Average Rate	0.00%		0.00%
Notional Amount	0		0
Assets at Fair Value	0	[1]	0	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 37-48 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'43 days		'46 months
Weighted Average Rate	0.73%		0.55%
Notional Amount	100,000,000		50,000,000
Assets at Fair Value	950,000	[1]	801,000	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 49-60 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'53 months
Weighted Average Rate	0.00%		0.92%
Notional Amount	0		50,000,000
Assets at Fair Value	0	[1]	532,000	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 61-72 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'0 months
Weighted Average Rate	0.00%		0.00%
Notional Amount	0		0
Assets at Fair Value	0	[1]	0	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 73-84 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'0 months
Weighted Average Rate	0.00%		0.00%
Notional Amount	0		0
Assets at Fair Value	0	[1]	0	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 85-96 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'0 days		'0 months
Weighted Average Rate	0.00%		0.00%
Notional Amount	0		0
Assets at Fair Value	0	[1]	0	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 97-108 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'104 days		'105 months
Weighted Average Rate	1.76%		1.50%
Notional Amount	601,250,000		175,000,000
Assets at Fair Value	20,703,000	[1]	15,023,000	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swap 109-120 Months | Swap	'		'
Derivative [Line Items]	'		'
Weighted Average Remaining Swap / Option Term (Months)	'112 days		'112 months
Weighted Average Rate	2.05%		1.91%
Notional Amount	100,000,000		526,250,000
Assets at Fair Value	3,658,000	[1]	36,463,000	[1]
Liabilities at Fair Value	0	[1]	0	[1]
Interest Rate Swaptions 60 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'60 months		'60 months
Weighted Average Remaining Swap / Option Term (Months)	'3 days		'9 months
Weighted Average Rate	2.73%		2.73%
Notional Amount	750,000,000		750,000,000
Assets at Fair Value	163,000	[1]	6,884,000	[1]
Liabilities at Fair Value	$0	[1]	$0	[1]
Minimum | Interest Rate Swap 0-12 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'0 months		'0 months
Minimum | Interest Rate Swap 13-24 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'13 months		'13 months
Minimum | Interest Rate Swap 25-36 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'25 months		'25 months
Minimum | Interest Rate Swap 37-48 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'37 months		'37 months
Minimum | Interest Rate Swap 49-60 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'49 months		'49 months
Minimum | Interest Rate Swap 61-72 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'61 months		'61 months
Minimum | Interest Rate Swap 73-84 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'73 months		'73 months
Minimum | Interest Rate Swap 85-96 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'85 months		'85 months
Minimum | Interest Rate Swap 97-108 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'97 months		'97 months
Minimum | Interest Rate Swap 109-120 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'109 months		'109 months
Maximum | Interest Rate Swap 0-12 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'12 months		'12 months
Maximum | Interest Rate Swap 13-24 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'24 months		'24 months
Maximum | Interest Rate Swap 25-36 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'36 months		'36 months
Maximum | Interest Rate Swap 37-48 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'48 months		'48 months
Maximum | Interest Rate Swap 49-60 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'60 months		'60 months
Maximum | Interest Rate Swap 61-72 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'72 months		'72 months
Maximum | Interest Rate Swap 73-84 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'84 months		'84 months
Maximum | Interest Rate Swap 85-96 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'96 months		'96 months
Maximum | Interest Rate Swap 97-108 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'108 months		'108 months
Maximum | Interest Rate Swap 109-120 Months | Swap	'		'
Derivative [Line Items]	'		'
Remaining / Underlying Term	'120 months		'120 months
[1]	See Note 5, “Fair Value of Financial Instruments” for additional discussion.

Derivatives_Details_Potential_

Derivatives (Details) - Potential Effects of Netting Derivative Instruments On the Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'	'
Gross and Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet	$25,474	$59,703
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Financial Instruments - Assets	0	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Cash Collateral Held - Assets	-23,290	-52,315
Net Amount - Assets	2,184	7,388
Interest rate swap contracts	'	'
Derivative [Line Items]	'	'
Gross and Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet	25,311	52,819
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Financial Instruments - Assets	0	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Cash Collateral Held - Assets	-23,290	-52,315
Net Amount - Assets	2,021	504
Interest rate swaptions	'	'
Derivative [Line Items]	'	'
Gross and Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet	163	6,884
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Financial Instruments - Assets	0	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Cash Collateral Held - Assets	0	0
Net Amount - Assets	$163	$6,884

Derivatives_Details_Location_a

Derivatives (Details) - Location and Information of Derivatives (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Unrealized gain (loss) on derivatives	($15,703)	$43,181	($35,732)	$46,626
Totals	-18,800	41,192	-41,935	43,687
Interest rate swap contracts	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Totals	-16,239	34,981	-35,214	37,147
Interest rate swap contracts | Realized Loss on Derivatives	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Realized gain on derivative	263	204	503	317
Realized loss on derivatives	-3,360	-2,193	-6,706	-3,256
Interest rate swap contracts | Unrealized Gain (Loss) on Derivatives	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Unrealized gain (loss) on derivatives	-13,142	36,970	-29,011	40,086
Interest rate swaptions	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Totals	-2,561	6,211	-6,721	6,540
Interest rate swaptions | Unrealized Gain (Loss) on Derivatives	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Unrealized gain (loss) on derivatives	($2,561)	$6,211	($6,721)	$6,540

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Other Commitments [Line Items]	'	'	'	'
Gross equity raised threshold used in calculation of management fee	$1,000,000,000	'	$1,000,000,000	'
Management fee	915,000	790,000	1,828,000	1,352,000
Gross Equity Raised up to One Billion U.S. Dollars	'	'	'	'
Other Commitments [Line Items]	'	'	'	'
Percentage of gross equity raised used in calculation of management fee up to $1 billion	1.50%	'	1.50%	'
Gross Equity Raised in Excess of One Billion U.S. Dollars	'	'	'	'
Other Commitments [Line Items]	'	'	'	'
Percentage of gross equity raised used in calculation of management fee up to $1 billion	1.00%	'	1.00%	'
Other Expense | ARRM	'	'	'	'
Other Commitments [Line Items]	'	'	'	'
Management fee	$95,000	$27,000	$179,000	$37,000

Stock_Based_Compensation_Detai

Stock Based Compensation (Details)	Jun. 30, 2014
In Thousands, unless otherwise specified
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Maximum number of common shares reserved for grant of awards as percentage of total common shares issued and outstanding	3.00%
Number of shares available for grant (in shares)	360

Stockholders_Equity_Details_Co

Stockholders' Equity (Details) - Common Stock Dividend Transactions (USD $)

0 Months Ended

3 Months Ended

6 Months Ended

In Thousands, except Per Share data, unless otherwise specified

Jun. 27, 2014

Jun. 16, 2014

29-May-14

15-May-14

Apr. 29, 2014

Apr. 15, 2014

Mar. 28, 2014

Mar. 17, 2014

Feb. 27, 2014

Feb. 14, 2014

Jan. 30, 2014

Jan. 15, 2014

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Equity [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividends declared per share (in usd per share)

'

$0.15

'

$0.15

'

$0.15

'

$0.15

'

$0.15

'

$0.15

'

'

'

'

Rate per common share (in usd per share)

$0.15

'

$0.15

'

$0.15

'

$0.15

'

$0.15

'

$0.15

'

$0.45

$0.69

$0.90

$1.38

Aggregate amount paid to holders of record (in Dollars)

$1,800

'

$1,799

'

$1,799

'

$1,799

'

$1,799

'

$1,799

'

$5,398

'

$10,795

$13,110

Income_Taxes_Details

Income Taxes (Details) (USD $)	0 Months Ended						3 Months Ended	6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 27, 2014	29-May-14	Apr. 29, 2014	Mar. 28, 2014	Feb. 27, 2014	Jan. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'
Amount of aggregate tax basis of assets and liabilities in excess of stockholders' equity	'	'	'	'	'	'	($33,730)	($33,730)	'	'
Amount of aggregate tax basis of assets and liabilities in excess of stockholders equity (in dollars per share)	'	'	'	'	'	'	($2.81)	($2.81)	'	'
Common stock, shares outstanding (in Shares)	'	'	'	'	'	'	11,999	11,999	'	11,993
Common stock dividends paid	1,800	1,799	1,799	1,799	1,799	1,799	5,398	10,795	13,110	'
Estimated taxable income available for dividends	'	'	'	'	'	'	$4,917	$10,095	'	'

Income_Taxes_Details_Reconcili

Income Taxes (Details) - Reconciliation of GAAP Net Income to Estimated REIT Taxable Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Disclosure [Abstract]	'	'	'	'
GAAP net income (loss)	($8,776)	$38,237	($10,639)	$49,213
Book to tax differences:	'	'	'	'
Net book to tax differences on Non-Agency Securities and Linked Transactions	-2,003	8,359	-5,699	6,634
Unrealized loss on U.S. Treasury Securities sold short	0	2,716	0	2,716
Realized capital loss on short sale of U.S. Treasury Securities	0	390	0	390
(Gain) loss on sale of Agency Securities	34	0	-8,776	0
Amortization of deferred hedging gains	146	0	291	0
Net premium amortization differences	181	0	809	0
Changes in interest rate contracts	15,703	-43,181	35,732	-46,626
Other	-6	0	-5	2
Estimated taxable income	$4,917	$6,521	$10,095	$12,329

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Related Party Transaction [Line Items]	'	'	'	'
Initial Term of Management Agreement	'	'	'5 years	'
Automatic Renewal Period of Management Agreement	'	'	'1 year	'
Period of written notice of termination	'	'	'180 days	'
Management fee	$915	$790	$1,828	$1,352
Sub-manager agreement monthly retainer fee	'	'	115	'
Percentage of monthly management fee	'	'	25.00%	'
Other Expense | ARRM	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'
Management fee	$95	$27	$179	$37

Subsequent_events_Details

Subsequent events (Details) (USD $)	0 Months Ended						3 Months Ended		6 Months Ended		0 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 27, 2014	29-May-14	Apr. 29, 2014	Mar. 28, 2014	Feb. 27, 2014	Jan. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jul. 30, 2014
											Subsequent Event
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Dividends paid per common share (in usd per share)	$0.15	$0.15	$0.15	$0.15	$0.15	$0.15	$0.45	$0.69	$0.90	$1.38	$0.15
Common stock dividends paid	$1,800	$1,799	$1,799	$1,799	$1,799	$1,799	$5,398	'	$10,795	$13,110	$1,800