Dynex Capital (DX) 10-Q 12 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 08, 2013
Entity Information [Line Items]	'	'
Entity Registrant Name	'DYNEX CAPITAL INC	'
Entity Central Index Key	'0000826675	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	54,428,943

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS	'	'
Mortgage-backed securities, at fair value	$4,141,744	$4,103,981
Financing Receivable, Net	59,797	70,823
Other investments, net	1,305	858
Total investments, net	4,202,846	4,175,662
Cash and cash equivalents	39,608	55,809
Restricted cash	15,849	0
Derivative assets	12,908	0
Principal receivable on investments	18,267	17,008
Accrued interest receivable	22,167	23,073
Other assets, net	7,999	8,677
Total assets	4,319,644	4,280,229
Liabilities:	'	'
Repurchase agreements	3,674,850	3,564,128
Non recourse collateralized financing	21,148	30,504
Derivative Liabilities	20,837	42,537
Accrued interest payable	2,433	2,895
Accrued dividends payable	16,632	16,770
Other liabilities	2,703	6,685
Total liabilities	3,738,603	3,663,519
Shareholders’ equity:	'	'
Common stock, par value $.01 per share, 100,000,000 shares authorized; 54,835,420 and 54,268,915 shares issued and outstanding, respectively	544	543
Additional paid-in capital	761,862	759,214
Accumulated other comprehensive income	-34,363	52,511
Accumulated deficit	-256,660	-250,965
Total shareholders' equity	581,041	616,710
Total liabilities and shareholders’ equity	4,319,644	4,280,229
Series A Preferred Stock [Member]	'	'
Shareholders’ equity:	'	'
Preferred Stock	55,407	55,407
Series B Preferred Stock [Member]	'	'
Shareholders’ equity:	'	'
Preferred Stock	$54,251	$0

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
ASSETS	'	'
Pledged MBS	$4,013,556	$3,967,134
Common stock, par value	$0.01	$0.01
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	54,426,049	54,268,915
Common stock, shares outstanding	54,426,049	54,268,915
Series A Preferred Stock [Member]	'	'
ASSETS	'	'
Preferred Stock, Par Value Per Share	$0.01	$0.01
Preferred Stock, Shares Authorized	8,000,000	8,000,000
Preferred Stock, Shares Issued	2,300,000	2,300,000
Preferred Stock, Shares Outstanding	2,300,000	2,300,000
Preferred Stock, aggregate liquidation preference	57,500	57,500
Series B Preferred Stock [Member]	'	'
ASSETS	'	'
Preferred Stock, Par Value Per Share	$0.01	$0
Preferred Stock, Shares Authorized	7,000,000	0
Preferred Stock, Shares Issued	2,250,000	0
Preferred Stock, Shares Outstanding	2,250,000	0
Preferred Stock, aggregate liquidation preference	$56,250	$0

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest income:	'	'	'	'
Mortgage-backed securities	$30,820	$27,254	$95,827	$77,236
Securitized mortgage loans	832	1,299	2,659	4,330
Other investments	14	21	52	405
Total interest income	31,666	28,574	98,538	81,971
Interest expense:	'	'	'	'
Repurchase agreements	8,477	9,166	29,860	23,673
Non recourse collateralized financing	241	308	760	1,043
Total interest expense	8,718	9,474	30,620	24,716
Net interest income	22,948	19,100	67,918	57,255
Provision for loan losses	0	-110	-261	-170
Net interest income after provision for loan losses	22,948	18,990	67,657	57,085
Gain on derivative instruments, net	-24,019	-333	-12,683	-907
Gain on sale of investments, net	-825	3,480	2,597	6,418
Fair value adjustments, net	150	297	-590	778
Other (expense) income, net	748	-177	761	350
General and administrative expenses:	'	'	'	'
Compensation and benefits	-2,282	-1,699	-6,948	-5,276
Other general and administrative	-1,347	-1,391	-4,284	-3,959
Net income	-4,627	19,167	46,510	54,489
Preferred Stock Dividends	-2,294	-814	-5,608	-814
Net income to common shareholders	($6,921)	$18,353	$40,902	$53,675
Weighted average common shares:	'	'	'	'
Basic	54,903,637	54,367,349	54,727,950	52,751,763
Diluted	54,903,637	54,368,215	54,727,950	52,751,763
Net income per common share:	'	'	'	'
Basic Net Income Per Common Share	($0.13)	$0.34	$0.75	$1.02
Diluted Net Income Per Common Share	($0.13)	$0.34	$0.75	$1.02
Dividends declared per common share	$0.27	$0.29	$0.85	$0.86

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Income	($4,627)	$19,167	$46,510	$54,489
Change in fair value of available-for-sale securities	-2,671	44,905	-112,037	80,671
Reclassification adjustment for gain on sale of investments, net included in statement of income	825	-3,275	-2,597	-3,275
Change in fair value of cash flow hedges	0	-11,073	16,381	-28,853
Reclassification adjustment for cash flows hedges included in statement of income	2,583	3,827	11,379	10,602
Other comprehensive income	737	34,384	-86,874	59,145
Total comprehensive income	-3,890	53,551	-40,364	113,634
Preferred Stock Dividends	-2,294	-814	-5,608	-814
Comprehensive Income to Common Shareholders	($6,184)	$52,737	($45,972)	$112,820

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities:	'	'
Net income	$46,510	$54,489
Adjustments to reconcile net income to cash provided by operating activities:	'	'
Increase in accrued interest receivable	906	-9,383
Decrease in accrued interest payable	-462	216
Provision for loan losses	261	170
Loss on derivative instruments, net	12,683	907
Gain on sale of investments, net	-2,597	-6,418
Fair value adjustments, net	590	-778
Amortization and depreciation	102,258	58,999
Stock-based compensation expense	1,762	1,294
Net change in other assets and other liabilities	-3,907	-2,347
Net cash and cash equivalents provided by operating activities	158,004	97,149
Investing activities:	'	'
Purchase of investments	-1,325,082	-2,454,851
Principal payments received on investments	743,810	459,380
(Increase) decrease in principal receivable on investments	-1,259	-6,548
Proceeds from sales of investments	327,962	185,485
Principal payments received on securitized mortgage loans	10,775	34,038
Net payments on derivatives not designated as hedges	-23,644	0
Other investing activities	5,402	-3,001
Net cash and cash equivalents used in investing activities	-262,036	-1,785,497
Financing activities:	'	'
Borrowings under repurchase agreements, net	110,409	1,577,943
Deferred borrowing costs paid	0	-825
Principal payments on non-recourse collateralized financing	-9,502	-39,773
Increase in restricted cash	-15,849	0
Proceeds from issuance of preferred stock	54,251	55,407
Proceeds from issuance of common stock	7,375	123,832
Cash paid for repurchases of common stock	-5,965	0
Payments Related to Tax Withholding for Share-based Compensation	-545	0
Dividends paid	-52,343	-42,289
Net cash and cash equivalents provided by financing activities	87,831	1,674,295
Net increase in cash and cash equivalents	-16,201	-14,053
Cash and cash equivalents at beginning of period	55,809	48,776
Cash and cash equivalents at end of period	39,608	34,723
Supplemental Disclosure of Cash Activities:	'	'
Cash paid for interest	$22,065	$24,284

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Basis of Presentation
	The accompanying consolidated financial statements of Dynex Capital, Inc. and its qualified real estate investment trust (“REIT”) subsidiaries and its taxable REIT subsidiary (together, “Dynex” or the “Company”) have been prepared in accordance with the instructions to the Quarterly Report on Form 10-Q and Article 10, 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 notes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements.  The financial information included herein is unaudited; however, in the opinion of management, all significant adjustments, consisting of normal recurring accruals considered necessary for a fair presentation of the consolidated financial statements, have been included.  Operating results for the three and nine months ended September 30, 2013 are not necessarily indicative of the results that may be expected for any other interim periods or for the entire year ending December 31, 2013.  The unaudited consolidated financial statements included herein should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012 filed with the SEC.
	Certain items in the prior years' consolidated financial statements have been reclassified to conform to the current year’s presentation.  The Company’s consolidated balance sheet as of December 31, 2012 now presents its Agency and non-Agency mortgage-backed securities as "mortgage-backed securities, at fair value". The Company's consolidated statements of income for the three and nine months ended September 30, 2012 now present interest income from Agency and non-Agency mortgage-backed securities together as "interest income: mortgage-backed securities". In addition, changes in fair value and other activity related to the Company's derivative instruments have been reclassified from "fair value adjustments, net" to "gain (loss) on derivative instruments, net". As a result, the respective amounts on the Company's consolidated statement of cash flows for the nine months ended September 30, 2012 have been changed to reflect this reclassification. These presentation changes have no effect on reported total assets, total liabilities, results of operations, or cash flow activities.
	Consolidation
	The consolidated financial statements include the accounts of the Company, its qualified REIT subsidiaries and its taxable REIT subsidiary.  The consolidated financial statements represent the Company’s accounts after the elimination of intercompany balances and transactions.  The Company consolidates entities in which it owns more than 50% of the voting equity and control does not rest with others and variable interest entities in which it is determined to be the primary beneficiary in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 810-10.  The Company follows the equity method of accounting for investments in which it owns greater than a 20% and less than 50% interest in partnerships and corporate joint ventures or when it is able to influence the financial and operating policies of the investee but owns less than 50% of the voting equity.
	In accordance with ASC Topic 810-10, the Company also consolidates certain trusts through which it has securitized mortgage loans. Additional information regarding the accounting policy for securitized mortgage loans is provided below under "Investments".
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenue and expenses during the reported period.  Actual results could differ from those estimates.  The most significant estimates used by management include but are not limited to fair value measurements of its investments, allowance for loan losses, other-than-temporary impairments, contingencies, and amortization of premiums and discounts. These items are discussed further below within this note to the consolidated financial statements.
	Federal Income Taxes
	The Company believes it has complied with the requirements for qualification as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”).  As such, the Company believes that it qualifies as a REIT for federal income tax purposes, and it generally will not be subject to federal income tax on the amount of its income or gain that is distributed as dividends to shareholders.  The Company uses the calendar year for both tax and financial reporting purposes.  There may be differences between taxable income and income computed in accordance with GAAP.
	Cash and Cash Equivalents
	Cash and cash equivalents include cash on hand and highly liquid investments with original maturities of three months or less.
	Restricted Cash
	Restricted cash consists of cash the Company has pledged to cover initial and variation margin with its counterparties.
	Investments
	The Company’s investments include Agency mortgage-backed securities ("MBS"), non-Agency MBS, securitized mortgage loans, and other investments.
	Agency MBS. The Company accounts for its investment in Agency MBS in accordance with ASC Topic 320, which requires that investments in debt and equity securities be designated at the time of acquisition as either “held-to-maturity,” “available-for-sale” or “trading”.  As of September 30, 2013, the majority of the Company's Agency MBS are designated as available-for-sale (or "AFS") with the remainder designated as trading.  Although the Company generally intends to hold its available-for-sale securities until maturity, it may, from time to time, sell any of these securities as part of the overall management of its business.  The available-for-sale designation provides the Company with this flexibility.
	All of the Company’s Agency MBS are recorded at their fair value on the consolidated balance sheet. In accordance with ASC Topic 820, the Company determines the fair value of its Agency MBS based upon prices obtained from a third-party pricing service and broker quotes. The Company's application of ASC Topic 820 guidance is discussed further in Note 7. Changes in the fair value of Agency MBS designated as trading are recognized in net income within “fair value adjustments, net”.  Gains and losses realized upon the sale, impairment, or other disposal of a trading security are also recognized within “fair value adjustments, net”.  Alternatively, changes in the fair value of Agency MBS designated as available-for-sale are reported in other comprehensive income as unrealized gains (losses) until the security is collected, disposed of, or determined to be other than temporarily impaired.  Upon the sale of an available-for-sale security, any unrealized gain or loss is reclassified out of accumulated other comprehensive income (“AOCI”) into net income as a realized “gain (loss) on sale of investments, net” using the specific identification method.
	Non-Agency MBS.  The Company accounts for its investment in non-Agency MBS in accordance with ASC Topic 320.  As of September 30, 2013, all of the Company’s non-Agency MBS are designated as available-for-sale and are recorded at their fair value on the consolidated balance sheet.  Changes in fair value are reported in other comprehensive income until the security is collected, disposed of, or determined to be other than temporarily impaired. Like Agency MBS, the Company generally intends to hold its investments in non-Agency MBS until maturity, but it may, from time to time sell any of these securities as part of the overall management of its business.  Upon the sale of an available-for-sale security, any unrealized gain or loss is reclassified out of AOCI into net income as a realized “gain (loss) on sale of investments, net” using the specific identification method.
	In accordance with ASC Topic 820, the Company determines the fair value for the majority of its non-Agency MBS based upon prices obtained from a third-party pricing service and broker quotes.  The remainder of the non-Agency MBS are valued by discounting the estimated future cash flows derived from cash flow models that utilize information such as the security’s coupon rate, estimated prepayment speeds, expected weighted average life, collateral composition, estimated future interest rates, expected losses, credit enhancement, as well as certain other relevant information. The Company's application of ASC Topic 820 guidance is discussed further in Note 7.
	Other-than-Temporary Impairment. The Company evaluates all MBS in its investment portfolio for other-than-temporary impairments by applying the guidance prescribed in ASC Topic 320-10. The Company compares the amortized cost of each security in an unrealized loss position against the present value of expected future cash flows of the security. If there has been a significant adverse change in the cash flow expectations for a security resulting in its amortized cost becoming greater than the present value of its expected future cash flows, an other-than-temporary credit impairment has occurred. If the Company does not intend to sell and is not more likely than not required to sell the security, the credit loss is recognized in earnings and the balance of the unrealized loss is recognized in other comprehensive income (loss). If the Company intends to sell the security or will be more likely than not required to sell the security, the full unrealized loss is recognized in earnings.
	In periods after the recognition of an other-than-temporary impairment loss for MBS, the Company shall account for the other-than-temporarily impaired MBS as if the MBS had been purchased on the measurement date of the other-than-temporary impairment at an amortized cost basis equal to the previous amortized cost basis less the other-than-temporary impairment recognized in earnings. For MBS for which other-than-temporary impairments were recognized in earnings, the difference between the new amortized cost basis and the cash flows expected to be collected shall be accreted into interest income using the effective interest method. The Company shall continue to estimate the present value of cash flows expected to be collected over the life of the MBS. For all other MBS, if upon subsequent evaluation, there is an increase in the cash flows expected to be collected or if actual cash flows are greater than cash flows previously expected, such changes shall be accounted for as a prospective adjustment to the accretable yield in accordance with Subtopic 310-30 even if the MBS would not otherwise be within the scope of that Subtopic. Subsequent increases and decreases in the fair value of the MBS that are not other-than-temporary shall be included in other comprehensive income. Please see Note 3 for additional information related to the Company's evaluation for other-than-temporary impairments.
	Securitized Mortgage Loans.  Securitized mortgage loans consist of loans pledged to support the repayment of securitization financing bonds issued by the Company. The associated securitization financing bonds are treated as debt of the Company and are presented as a portion of "non-recourse collateralized financing" on the consolidated balance sheet. In accordance with ASC Topic 310-10, the Company's securitized mortgage loans are reported at amortized cost.  Securitized mortgage loans can only be sold subject to the lien of the respective securitization financing indenture. An allowance has been established for currently existing and probable losses on such loans as further discussed below.
	Other Investments.  Other investments include unsecuritized mortgage loans owned by the Company as well as the Company's investment in a limited partnership that invests in pools of non-qualifying mortgage loans. The Company accounts for its other investments using the cost method in accordance with ASC Topic 325-20.
	Allowance for Loan Losses. An allowance for loan losses has been estimated and established for currently existing and probable losses for securitized and unsecuritized mortgage loans that are considered impaired in accordance with ASC Topic 310-10.  Provisions made to increase the allowance are charged as a current period expense.  Commercial mortgage loans are secured by income-producing real estate and are evaluated individually for impairment when the debt service coverage ratio on the mortgage loan is less than 1:1 or when the mortgage loan is delinquent.  Commercial mortgage loans not evaluated for individual impairment are evaluated for a general allowance.  Certain of the commercial mortgage loans are covered by mortgage loan guarantees that limit the Company’s exposure on these mortgage loans.  Single-family mortgage loans are considered homogeneous and are evaluated on a pool basis for a general allowance.
	The Company considers various factors in determining its specific and general allowance requirements, including whether a loan is delinquent, the Company’s historical experience with similar types of loans, historical cure rates of delinquent loans, and historical and anticipated loss severity of the mortgage loans as they are liquidated.  The factors may differ by mortgage loan type (e.g., single-family versus commercial) and collateral type (e.g., multifamily versus office property).  The allowance for loan losses is evaluated and adjusted periodically by management based on the actual and estimated timing and amount of probable credit losses, using the above factors, as well as industry loss experience.
	Repurchase Agreements
	Repurchase agreements are treated as financings in accordance with the provision of ASC Topic 860 under which the Company pledges its securities as collateral to secure a loan, which is equal in value to a specified percentage of the estimated fair value of the pledged collateral. The Company retains beneficial ownership of the pledged collateral.  At the maturity of a repurchase agreement, the Company is required to repay the loan and concurrently receives back its pledged collateral from the lender or, with the consent of the lender, the Company may renew the agreement at the then prevailing financing rate.  A repurchase agreement lender may require the Company to pledge additional collateral in the event of a decline in the fair value of the collateral pledged.  Repurchase agreement financing is recourse to the Company and the assets pledged.  Most of the Company’s repurchase agreements are based on the September 1996 version of the Bond Market Association Master Repurchase Agreement, which generally provides that the lender, as buyer, is responsible for obtaining collateral valuations from a generally recognized source agreed to by both the Company and the lender, or, in an instance when such source is not available, the value determination is made by the lender.
	Derivative Instruments
	The Company accounts for its derivative instruments in accordance with ASC Topic 815. ASC Topic 815 requires an entity to recognize all derivatives as either assets or liabilities in the balance sheet and to measure those instruments at fair value.
	Effective June 30, 2013, the Company discontinued hedge accounting for derivative instruments which had previously been accounted for as cash flow hedges under ASC Topic 815. Activity up to and including June 30, 2013 for those agreements previously designated as cash flow hedges was recorded in accordance with cash flow hedge accounting as prescribed by ASC Topic 815, which states that the effective portion of the hedge relationship on an instrument designated as a cash flow hedge is reported in the current period's other comprehensive income while the ineffective portion is immediately reported in the current period’s consolidated statement of income. The balance remaining in AOCI related to the de-designated cash flow hedges is being recognized in the Company's consolidated statement of income as a portion of "interest expense" over the remaining life of the interest rate swap agreements. Subsequent to June 30, 2013 changes in the fair value of the Company's derivative instruments, plus periodic settlements, are recorded in the Company's consolidated statement of income as a portion of "(loss) gain on derivative instruments, net".
	The Company has Eurodollar futures, which are valued based on closing exchange prices. Variation margin is exchanged daily to settle any changes in the value of the Eurodollar futures. Gains and losses associated with purchases and short sales of futures contracts are reported in "(loss) gain on derivative instruments, net", in our consolidated statements of income.
	The Company has elected to use the portfolio exception in ASC 820-10-35-18D with respect to measuring counterparty credit risk for derivative instruments. The Company manages credit risk for its derivative positions on a counterparty-by-counterparty basis (that is, on the basis of its net portfolio exposure with each counterparty), consistent with its risk management strategy for such transactions. The Company manages credit risk by considering indicators of risk such as credit ratings, and by negotiating terms in its ISDA master netting arrangements and, if applicable, any associated Credit Support Annex documentation, with each individual counterparty. Since the effective date of ASC 820, management has monitored and measured credit risk and calculated credit valuation adjustments for its derivative transactions on the basis of its relationships at the counterparty portfolio level. Management receives reports from an independent third-party valuation specialist on a monthly basis providing the credit valuation adjustments at the counterparty portfolio level for purposes of reviewing and managing its credit risk exposures. Since the portfolio exception applies only to the fair value measurement and not to financial statement presentation, the portfolio-level adjustments are then allocated in a reasonable and consistent manner each period to the individual assets or liabilities that make up the group, in accordance with other applicable accounting guidance and the Company's accounting policy elections.
	Although MBS have characteristics that meet the definition of a derivative instrument, ASC 815 specifically excludes these instruments from its scope because they are accounted for as debt securities under ASC 320.
	Interest Income, Premium Amortization, and Discount Accretion
	Interest income is accrued based on the outstanding principal balance (or notional balance in the case of interest-only, or "IO", securities) on the Company's investment securities and their contractual terms. Premiums and discounts on Agency and non-Agency MBS and on loans are recognized over the expected life of the investment using the effective yield method in accordance with ASC Topic 310-20. Adjustments to premium amortization are made for actual prepayment activity as well as changes in projected future cash flows in accordance with 320-10. Interest income on non-Agency MBS that are rated lower than “AA” are recognized over the expected life as adjusted for the estimated prepayments and credit losses of the securities.  Actual prepayment and any credit losses experienced are compared to projected prepayments and credit losses, and effective yields are adjusted when those amounts differ.
	The Company's projections of future cash flows are based on input and analysis received from external sources and internal models, and includes assumptions about the amount and timing of credit losses, loan prepayment rates, fluctuations in interest rates, and other factors. On at least a quarterly basis, the Company reviews and makes any necessary adjustments to its cash flow projections and updates the yield recognized on these assets.
	For securities, the accrual of interest is discontinued when, in the opinion of management, it is probable that all amounts contractually due will not be collected, and in certain instances, as a result of the other-than-temporary impairment analysis. For loans, the accrual of interest is discontinued when, in the opinion of management, the interest is not collectible in the normal course of business, when the loan is significantly past due or when the primary servicer of the loan fails to advance the interest and/or principal due on the loan.  Loans are considered past due when the borrower fails to make a timely payment in accordance with the underlying loan agreement.  All interest accrued but not collected for investments that are placed on a non-accrual status or are charged-off is reversed against interest income.  Interest on these investments is accounted for on the cash-basis or cost-recovery method until qualifying for return to accrual status.  Investments are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured.
	Stock-Based Compensation
	Pursuant to the Company’s 2009 Stock and Incentive Plan ("SIP"), the Company may grant stock-based compensation to eligible employees, directors or consultants or advisers to the Company, including stock awards, stock options, stock appreciation rights (“SARs”), dividend equivalent rights, performance shares, and restricted stock units.  Currently, the Company's stock options and restricted stock issued under this plan may be settled only in shares of its common stock, and therefore are treated as equity awards with their fair value measured at the grant date as required by ASC Topic 718. Outstanding SARs issued by the Company may be settled only in cash, and therefore have been treated as liability awards with their fair value estimated at the grant date and remeasured at the end of each reporting period using the Black-Scholes option valuation model as required by ASC Topic 718.  Please see Note 8 for additional disclosures regarding the Company's SIP.
	Contingencies
	In the normal course of business, there are various lawsuits, claims, and other contingencies pending against the Company.  We evaluate whether to establish provisions for estimated losses from those matters in accordance with ASC Topic 450, which states that a liability is recognized for a contingent loss when: (a) the underlying causal event has occurred prior to the balance sheet date; (b) it is probable that a loss has been incurred; and (c) there is a reasonable basis for estimating that loss. A liability is not recognized for a contingent loss when it is only possible or remotely possible that a loss has been incurred, however, possible contingent losses shall be disclosed. Please refer to Note 9 for details on the most significant matters currently pending.
	Recent Accounting Pronouncements
	In July 2013, the FASB issued ASU 2013-10, Derivatives and Hedging (Topic 815), Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes(a consensus of the FASB Emerging Issues Task Force) ("ASU 2013-10"). The new guidance permits the use of the Federal Funds Effective Swap Rate as a benchmark interest rate for hedge accounting purposes and removes certain restrictions on being able to apply hedge accounting for similar hedges using different benchmark interest rates. ASU 2013-10 is effective prospectively for qualifying new or re-designated hedging relationships entered into on or after July 17, 2013. The adoption of this ASU does not have an impact on our derivatives and will not have a material impact on the Company's consolidated financial statements.
	In June 2013, the FASB issued ASU 2013-08, Financial Services - Investment Companies: Amendments to the Scope, Measurement, and Disclosure Requirements ("ASU 2013-08"). In general, the amendments of this ASU: (i) revise the definition of an investment company; (ii) require an investment company to measure non-controlling ownership interests in other investment companies at fair value rather than using the equity method of accounting; and (iii) require information to be disclosed concerning the status of the entity and any financial support provided, or contractually required to be provided, by the investment company to its investees. ASU 2013-08 is effective for interim and annual periods that begin after December 15, 2013 and early application is prohibited. As the FASB has decided to retain the current U.S. GAAP scope exception from investment company accounting and financial reporting for real estate investment trusts, the adoption of this ASU will not have a material impact on the Company's consolidated financial statements.

Net_Income_Per_Common_Share

Net Income Per Common Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share, Basic and Diluted [Abstract]	'
Net Income per Common Share	'
	NET (LOSS) INCOME PER COMMON SHARE
	Net (loss) income per common share is presented on both a basic and diluted basis.  Diluted net (loss) income per common share assumes the exercise of stock options, if any were outstanding during the period presented, using the treasury stock method. Because the Company's Series A and Series B Cumulative Redeemable Preferred Stock are redeemable at the Company's option for cash only, and may convert into shares of common stock only upon a change of control of the Company, the effect of those shares is excluded from the calculation of diluted net (loss) income per common share.
	Holders of unvested shares of our issued and outstanding restricted common stock are eligible to receive non-forfeitable dividends. As such, these unvested shares are considered participating securities as per ASC 260-10 and therefore are included in the computation of basic net (loss) income per share using the two-class method.
	The following table presents the calculation of the numerator and denominator for both basic and diluted net (loss) income per common share:
		Three Months Ended
		September 30,
		2013						2012
		Net Loss			Weighted-Average Common Shares			Net			Weighted-
								Income			Average
											Common
											Shares
	Net (loss) income	$	(4,627	)				$	19,167
	Preferred stock dividends	(2,294		)				(814		)
	Net (loss) income to common shareholders	(6,921		)	54,903,637			18,353			54,367,349
	Effect of dilutive stock options	—			—			—			866
	Diluted	$	(6,921	)	54,903,637			$	18,353		54,368,215
	Net (loss) income per common share:
	Basic				$	(0.13	)				$	0.34
	Diluted				$	(0.13	)				$	0.34
		Nine Months Ended
		September 30,
		2013						2012
		Net			Weighted-Average Common Shares			Net			Weighted-
		Income						Income			Average
											Common
											Shares
	Net income	$	46,510					$	54,489
	Preferred stock dividends	(5,608		)				(814		)
	Net income to common shareholders	40,902			54,727,950			53,675			52,751,763
	Effect of dilutive stock options	—			—			—			—
	Diluted	$	40,902		54,727,950			$	53,675		52,751,763
	Net income per common share:
	Basic				$	0.75					$	1.02
	Diluted (1)				$	0.75					$	1.02
	-1	For the nine months ended September 30, 2012, the calculation of diluted net income per common share excludes the effect of 15,000 unexercised stock option awards because their inclusion would have been anti-dilutive.

Mortgage_Backed_Securities_Mor

Mortgage Backed Securities Mortgage backed securities (Notes)	9 Months Ended
	Sep. 30, 2013
Schedule of Available-for-sale Securities [Line Items]	'
Mortgage-backed securities	'
	MORTGAGE-BACKED SECURITIES
	The following table presents the components of the Company’s MBS designated as AFS as of September 30, 2013 and December 31, 2012:
		September 30, 2013
		Par		Net Premium (Discount)			Amortized Cost				Net Unrealized Gain (Loss)				Fair Value			Weighted average coupon
	Agency:
	RMBS	$	2,723,084	$	162,370		$	2,885,454			$	(56,407	)		$	2,829,047		3.26	%
	CMBS	261,440		19,844			281,284				11,941				293,225			4.82	%
	CMBS IO (1)	—		466,494			466,494				9,114				475,608			0.89	%
	Total Agency AFS:	2,984,524		648,708			3,633,232				(35,352		)		3,597,880
	Non-Agency:
	RMBS	14,972		(351		)	14,621				(33		)		14,588			4.58	%
	CMBS	381,342		(17,213		)	364,129				10,620				374,749			5.52	%
	CMBS IO (1)	—		123,172			123,172				2,377				125,549			0.87	%
	Total non-Agency AFS:	396,314		105,608			501,922				12,964				514,886
	Total AFS securities	$	3,380,838	$	754,316		$	4,135,154			$	(22,388	)		$	4,112,766
	-1	The notional balance for Agency CMBS IO and non-Agency CMBS IO is $9,682,065 and $2,857,343, respectively, as of September 30, 2013.
		31-Dec-12
		Par		Net Premium (Discount)			Amortized Cost				Net Unrealized Gain (Loss)				Fair Value			Weighted average coupon
	Agency:
	RMBS	$	2,425,826	$	137,168		$	2,562,994			$	8,343			$	2,571,337		3.67	%
	CMBS	280,602		21,907			302,509				21,564				324,073			5.19	%
	CMBS IO (1)	—		550,171			550,171				17,009				567,180			0.95	%
	Total Agency AFS:	2,706,428		709,246			3,415,674				46,916				3,462,590
	Non-Agency:
	RMBS	11,411		(781		)	10,630				408				11,038			4.28	%
	CMBS	463,747		(17,313		)	446,434				39,908				486,342			5.31	%
	CMBS IO (1)	—		108,928			108,928				5,014				113,942			0.86	%
	Total non-Agency AFS:	475,158		90,834			565,992				45,330				611,322
	Total AFS securities	$	3,181,586	$	800,080		$	3,981,666			$	92,246			$	4,073,912
	-1	The notional balance for the Agency CMBS IO and non-Agency CMBS IO is $10,059,495 and $2,393,614, respectively, as of December 31, 2012.
	The Company has investments in additional Agency CMBS not included in the tables above that are designated as trading securities by the Company with fair values of $28,978 and $30,069 as of September 30, 2013 and December 31, 2012, respectively. Changes in the fair value of these Agency CMBS are recognized each reporting period within "fair value adjustments, net" in the Company's consolidated statements of income. As of September 30, 2013 and December 31, 2012, the amortized cost of these Agency CMBS designated as trading securities was $27,078 and $27,535, respectively. The Company recognized a net unrealized gain (loss) for the three and nine months ended September 30, 2013 of $96 and $(634), respectively, compared to a net unrealized gain of $283 and $716 for the three and nine months ended September 30, 2012, respectively, related to changes in fair value.
	The following table presents certain information for those Agency MBS in an unrealized loss position as of September 30, 2013 and December 31, 2012:
		30-Sep-13							31-Dec-12
		Fair Value		Gross Unrealized Losses			# of Securities		Fair Value				Gross Unrealized Losses				# of Securities
	Continuous unrealized loss position for less than 12 months:
	Agency MBS	$	2,129,694	$	(48,337	)	164		$	1,026,277			$	(6,552	)		83
	Non-Agency MBS	126,846		(5,902		)	23		13,877				(76		)		3
	Continuous unrealized loss position for 12 months or longer:
	Agency MBS	$	558,070	$	(17,718	)	67		$	271,719			$	(5,797	)		34
	Non-Agency MBS	1,820		(100		)	6		2,701				(198		)		8
	Because the principal and interest related to Agency MBS are guaranteed by the government-sponsored entities Fannie Mae and Freddie Mac who have the implicit guarantee of the U.S. government, the Company does not consider any of the unrealized losses on its Agency MBS to be credit related. Although the unrealized losses are not credit related, the Company assesses its ability and intent to hold any Agency MBS with an unrealized loss until the recovery in its value. This assessment is based on the amount of the unrealized loss and significance of the related investment as well as the Company’s current leverage and anticipated liquidity.  Based on this analysis, the Company has determined that the unrealized losses on its Agency MBS as of September 30, 2013 and December 31, 2012 were temporary.
	The Company also reviews any non-Agency MBS in an unrealized loss position to evaluate whether any decline in fair value represents an other-than-temporary impairment. The evaluation includes a review of the credit ratings of these non-Agency MBS and the seasoning of the mortgage loans collateralizing these securities as well as the estimated future cash flows which include projected losses. The Company performed this evaluation for the non-Agency MBS in an unrealized loss position and has determined that there have not been any adverse changes in the timing or amount of estimated future cash flows that necessitate a recognition of other-than-temporary impairment amounts as of September 30, 2013 or December 31, 2012.

Repurchase_Agreements

Repurchase Agreements	9 Months Ended
	Sep. 30, 2013
REPURCHASE AGREEMENTS [Abstract]	'
Repurchase Agreements	'
	REPURCHASE AGREEMENTS
	The following tables present the components of the Company’s repurchase agreements as of September 30, 2013 and December 31, 2012 by the fair value and type of securities pledged as collateral to the repurchase agreements:
		September 30, 2013
	Collateral Type	Balance			Weighted		Fair Value of
					Average Rate		Collateral Pledged
	Agency RMBS	$	2,634,120		0.41	%	2,721,562
	Agency CMBS	234,633			0.39	%	294,556
	Agency CMBS IOs	377,977			1.17	%	463,894
	Non-Agency RMBS	10,932			1.8	%	13,616
	Non-Agency CMBS	298,548			1.29	%	364,977
	Non-Agency CMBS IO	97,584			1.68	%	125,539
	Securitization financing bonds	21,403			1.6	%	24,853
	Deferred costs	(347		)	n/a		n/a
		$	3,674,850		0.59	%	$	4,008,997
		December 31, 2012
	Collateral Type	Balance			Weighted		Fair Value of Collateral Pledged
					Average Rate
	Agency RMBS	$	2,365,982		0.48	%	$	2,458,200
	Agency CMBS	248,771			0.47	%	291,445
	Agency CMBS IOs	443,540			1.22	%	565,494
	Non-Agency RMBS	7,808			1.84	%	9,634
	Non-Agency CMBS	382,352			1.34	%	465,306
	Non-Agency CMBS IOs	88,221			1.46	%	113,942
	Securitization financing bonds	28,113			1.64	%	31,483
	Deferred costs	(659		)	n/a		n/a
		$	3,564,128		0.7	%	$	3,935,504
	The combined weighted average original term to maturity for the Company’s repurchase agreements increased to 91 days as of September 30, 2013 from 57 days as of December 31, 2012. The Company has been able to extend the maturity dates for its repurchase agreements due to discontinuing cash flow hedge accounting. The following table provides a summary of the original maturities as of September 30, 2013 and December 31, 2012:
	Original Maturity	September 30,			December 31,
		2013			2012
	30 days or less	$	486,150		$	622,957
	31 to 60 days	677,725			1,263,105
	61 to 90 days	333,007			298,660
	91 to 120 days	1,021,594			1,092,681
	121 to 150 days	583,888			—
	Greater than 150 days	572,833			287,384
		$	3,675,197		$	3,564,787
	As of September 30, 2013, the Company had approximately 17% of its shareholders' equity at risk (defined as the excess of collateral pledged over the borrowing outstanding) with Wells Fargo Bank National Association together with its affiliate Wells Fargo Securities, LLC. The borrowings outstanding with that counterparty and its affiliates as of September 30, 2013 were $401,404 with a weighted average borrowing rate of 1.17%. Of the amount outstanding with this counterparty and its affiliate, $187,508 is under a two-year repurchase facility with Wells Fargo Bank National Association. The facility is collateralized primarily by CMBS IO, and its weighted average borrowing rate as of September 30, 2013 was 1.44%. Shareholders' equity at risk did not exceed 10% for any of the Company's other counterparties. Please see Note 10 regarding changes to the master repurchase agreement for this facility that occurred subsequent to September 30, 2013.
	As of September 30, 2013, the Company had repurchase agreement amounts outstanding with 21 of its 31 available counterparties. The Company's counterparties, as set forth in the master repurchase agreement with the counterparty, require the Company to comply with various customary operating and financial covenants, including, but not limited to, minimum net worth, maximum declines in net worth in a given period, and maximum leverage requirements as well as maintaining the Company's REIT status.  In addition, some of the agreements contain cross default features, whereby default under an agreement with one lender simultaneously causes default under agreements with other lenders.  To the extent that the Company fails to comply with the covenants contained in these financing agreements or is otherwise found to be in default under the terms of such agreements, the counterparty has the right to accelerate amounts due under the master repurchase agreement. The Company was in compliance with all covenants as of September 30, 2013.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivatives	'
	DERIVATIVES
	The Company utilizes a variety of derivative instruments to economically hedge a portion of its exposure to market risks, primarily interest rate risk. The principal instruments used to hedge these risks are interest rate swaps and Eurodollar futures. The objective of the Company's risk management strategy is to protect the Company's earnings from rising interest rates and to mitigate declines in book value resulting from fluctuations in the fair value of the Company's assets from changing interest rates. The Company seeks to limit its exposure to changes in interest rates but does not seek to eliminate this risk.
	Effective June 30, 2013, the Company voluntarily discontinued hedge accounting for interest rate swaps which had previously been accounted for as cash flow hedges under GAAP. The Company discontinued hedge accounting for its interest rate swap agreements in order to gain greater flexibility in managing the maturities of its repurchase agreement borrowings. In addition, the Company began purchasing Eurodollar futures during the third quarter of 2013. Please refer to Note 1 for additional information related to the Company's accounting policy for its derivative instruments.
	The table below summarizes information about the Company’s derivative instruments on its consolidated balance sheet as of the dates indicated:
							September 30, 2013
	Type of Derivative Instrument		Accounting Designation		Balance Sheet Location:		Fair Value			Aggregate Notional Amount
	Interest rate swaps		Non-hedging		Derivative assets		$	12,908		$	425,000
	Interest rate swaps		Non-hedging				$	(20,837	)	$	1,267,000
	Eurodollar futures		Non-hedging				—			20,250,000
					Derivative liabilities		$	(20,837	)	$	21,517,000
							31-Dec-12
	Type of Derivative Instrument		Accounting Designation		Balance Sheet Location:		Fair Value			Aggregate Notional Amount
	Interest rate swaps		Hedging				$	(39,813	)	$	1,435,000
	Interest rate swaps		Non-hedging				(2,724		)	27,000
					Derivative liabilities		$	(42,537	)	$	1,462,000
	(1) Margin requirements from fluctuations in fair value of the Company's Eurodollar futures are settled daily with counterparties.
	Information related to the volume of activity for our interest rate derivative instruments subsequent to December 31, 2012 is as follows:
	(amounts in thousands)	Interest Rate Swaps				Eurodollar Futures
	Notional amount as of December 31, 2012:	$	1,462,000			$	—
	Additions:	380,000				22,100,000
	Settlements, terminations, or expirations:	(150,000		)		(1,850,000		)
	Notional amount as of September 30, 2013:(1)	$	1,692,000			$	20,250,000
	-1	The Eurodollar futures notional amount as of September 30, 2013 represents the total notional of the 3-month contracts with expiration dates from 2013 to 2020. The maximum notional outstanding for any 3-month period does not exceed $1,275,000.
	The following table summarizes the contractual maturities remaining for the Company’s outstanding interest rate swap agreements as of September 30, 2013:
	Remaining		Notional Amount:				Weighted-Average
	Maturity		Trading				Fixed Rate Swapped
	0-12 months		$	435,000			1.26	%
	13-24 months		130,000				2.06	%
	25-36 months		260,000				1.96	%
	37-48 months		212,000				0.01	%
	49-60 months		15,000				2.17	%
	61-72 months		385,000				1.58	%
	73-84 months		25,000				1.61	%
	109-127 months		230,000				2.27	%
			$	1,692,000			1.64	%
	As of September 30, 2013, three of these agreements with a total notional balance of $150,000 and a weighted average pay-fixed rate of 2.17% are 10-year forward-starting swaps which will not be effective until 2014.
	The tables below summarize the effect of the Company's interest rate derivatives reported in "(loss) gain on derivative instruments, net" on the Company's consolidated statements of income for the periods indicated:
			Three Months Ended							Nine Months Ended
			September 30,							September 30,
	Type of Derivative Instrument		2013				2012			2013			2012
	Interest rate swaps		$	(6,225	)		$	(333	)	$	5,111		$	(907	)
	Eurodollar futures		(17,794		)		—			(17,794		)	—
	Loss on derivative instruments, net		$	(24,019	)		$	(333	)	$	(12,683	)	$	(907	)
	Please refer to Note 10 for important information regarding derivative instruments the Company has terminated subsequent to September 30, 2013.
	As a result of discontinuing hedge accounting, the net unrealized loss remaining in AOCI as of September 30, 2013 of $11,975 related to the interest rate swap agreements previously designated as cash flow hedges will be recognized into the Company's consolidated statement of income as a portion of "interest expense" over the remaining contractual life of the agreements. The Company reclassified $2,583 from AOCI to its consolidated statement of income for the three months ended September 30, 2013. All forecasted transactions associated with interest rate swap agreements previously designated as cash flow hedges are expected to occur. No amounts have been reclassified to net income (loss) in any period in connection with forecasted transactions that are no longer considered probable of occurring. The Company estimates the net amount of existing net unrealized loss on discontinued cash flow hedges expected to be reclassified to earnings within the next 12 months is $7,911.
	All of the Company's derivative instruments contain various covenants related to the Company’s credit risk.  Specifically, if the Company defaults on any of its indebtedness, including those circumstances whereby repayment of the indebtedness has not yet been accelerated by the lender, or is declared in default of any of its covenants with any counterparty, then the Company could also be declared in default of its derivative obligations. Additionally, the agreements outstanding with its derivative counterparties allow those counterparties to require settlement of its outstanding derivative transactions if the Company fails to earn GAAP net income greater than one dollar as measured on a rolling two quarter basis. These interest rate agreements also contain provisions whereby, if the Company fails to maintain a minimum net amount of shareholders’ equity, then the Company may be declared in default on its derivative obligatio

Offsetting_Assets_and_Liabilit

Offsetting Assets and Liabilities (Notes)	9 Months Ended
	Sep. 30, 2013
Offsetting Assets and Liabilities [Abstract]	'
Schedule of Derivative Instruments Offsetting Assets and Liabilities [Table Text Block]	'
	OFFSETTING ASSETS AND LIABILITIES
	The Company's derivatives and repurchase agreements are subject to underlying agreements with master netting or similar arrangements, which provide for the right of offset in the event of default or in the event of bankruptcy of either party to the transactions. The Company reports its assets and liabilities subject to these arrangements on a gross basis. The following tables present information regarding those assets and liabilities subject to such arrangements as if the Company had presented them on a net basis as of September 30, 2013 and December 31, 2012:
		Offsetting of Assets
		Gross Amount of Recognized Assets		Gross Amount Offset in the Balance Sheet		Net Amount of Assets Presented in the Balance Sheet		Gross Amount Not Offset in the Balance Sheet						Net Amount
								Financial Instruments Received as Collateral			Cash Received as Collateral
	30-Sep-13
	Derivative assets	$	12,908	$	—	$	12,908	$	(1,689	)	$	(11,219	)	$	—
	December 31, 2012:
	Derivative assets	$	—	$	—	$	—	$	—		$	—		$	—
		Offsetting of Liabilities
		Gross Amount of Recognized Liabilities		Gross Amount Offset in the Balance Sheet		Net Amount of Liabilities Presented in the Balance Sheet		Gross Amount Not Offset in the Balance Sheet						Net Amount
								Financial Instruments Posted as Collateral			Cash Posted as Collateral
	30-Sep-13
	Derivative liabilities	$	20,837	$	—	$	20,837	$	(20,175	)	$	(490	)	$	172
	Repurchase agreements	3,674,850		—		3,674,850		(3,674,850		)	—			—
		$	3,695,687	$	—	$	3,695,687	$	(3,695,025	)	$	(490	)	$	172
	December 31, 2012:
	Derivative liabilities	$	42,537	$	—	$	42,537	$	(42,499	)	$	(38	)	$	—
	Repurchase agreements	3,564,128		—		3,564,128		(3,564,128		)	—			—
		$	3,606,665	$	—	$	3,606,665	$	(3,606,627	)	$	(38	)	$	—
	(1) Amount disclosed for collateral received by or posted to the same counterparty include cash and the fair value of MBS up to and not exceeding the net amount of the asset or liability presented in the balance sheet. The fair value of the actual collateral received by or posted to the same counterparty may exceed the amounts presented.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments (Notes)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	FAIR VALUE OF FINANCIAL INSTRUMENTS
	ASC Topic 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. ASC 820 clarifies that fair value should be based on the assumptions market participants would use when pricing as asset or liability and also requires an entity to consider all aspects of nonperformance risk, including the entity's own credit standing, when measuring fair value of a liability. ASC Topic 820 established a valuation hierarchy of three levels as follows:
	•	Level 1 – Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities as of the measurement date. None of the Company's assets and liabilities that are measured at fair value are included in this category.
	•	Level 2 – Inputs include quoted prices in active markets for similar assets or liabilities; quoted prices in inactive markets for identical or similar assets or liabilities; or inputs either directly observable or indirectly observable through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.  The Company’s fair valued assets and liabilities that are generally included in this category are Agency MBS, certain non-Agency MBS, and derivatives.
	•	Level 3 – Unobservable inputs are supported by little or no market activity. The unobservable inputs represent management’s best estimate of how market participants would price the asset or liability at the measurement date.  Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.  The Company’s fair valued assets and liabilities that are generally included in this category are certain non-Agency MBS and other investments.
	The following table presents the fair value of the Company’s assets and liabilities, segregated by the hierarchy level of the fair value estimate, that are measured at fair value on a recurring basis as of the periods indicated:
		September 30, 2013
		Fair Value				Level 1 - Unadjusted Quoted Prices in Active Markets				Level 2 - Observable Inputs			Level 3 - Unobservable Inputs
	Assets:
	Mortgage-backed securities	$	4,141,744			$	—			$	4,039,331		$	102,413
	Derivative assets	12,908				—				12,908			—
	Total assets carried at fair value	$	4,154,652			$	—			$	4,052,239		$	102,413
	Liabilities:
	Derivative liabilities	$	20,837			$	—			$	20,837		$	—
	Total liabilities carried at fair value	$	20,837			$	—			$	20,837		$	—
		December 31, 2012
		Fair Value				Level 1 - Unadjusted Quoted Prices in Active Markets				Level 2 - Observable Inputs			Level 3 - Unobservable Inputs
	Assets:
	Mortgage-backed securities	$	4,103,981			$	—			$	3,998,761		$	105,220
	Other investments	25				—				—			25
	Total assets carried at fair value	$	4,104,006			$	—			$	3,998,761		$	105,245
	Liabilities:
	Derivative liabilities	$	42,537			$	—			$	42,537		$	—
	Total liabilities carried at fair value	$	42,537			$	—			$	42,537		$	—
	The Company’s valuation of its interest rate swaps is determined using the income approach. The primary input into the valuation represents the forward interest rate swap curve, which is considered an observable input and thus their fair values are considered Level 2 measurements. The Company's valuation of its Eurodollar futures is based on the closing exchange prices. Accordingly, these financial futures are classified as Level 1.
	The Company’s Agency MBS, as well a majority of its non-Agency MBS, are substantially similar to securities that either are currently actively traded or have been recently traded in their respective market.  Their fair values are derived from an average of multiple dealer quotes and thus are considered Level 2 fair value measurements. The Company’s remaining non-Agency MBS are comprised of securities for which there are not substantially similar securities that trade frequently.  As such, the Company determines the fair value of those securities by discounting the estimated future cash flows derived from cash flow models using assumptions that are confirmed to the extent possible by third party dealers or other pricing indicators.  Significant inputs into those pricing models are Level 3 in nature due to the lack of readily available market quotes.  Information utilized in those pricing models include the security’s credit rating, coupon rate, estimated prepayment speeds, expected weighted average life, collateral composition, estimated future interest rates, expected credit losses, and credit enhancement as well as certain other relevant information.  Significant changes in any of these inputs in isolation would result in a significantly different fair value measurement. Generally Level 3 assets are most sensitive to the default rate and severity assumptions.
	The table below presents information about the significant unobservable inputs used in the fair value measurement for the Company's Level 3 non-Agency CMBS and RMBS as of September 30, 2013:
		Quantitative Information about Level 3 Fair Value Measurements(1)
		Prepayment Speed			Default Rate			Severity			Discount Rate
	Non-Agency CMBS	20 CPY			2.5	%		35	%		6.5	%
	Non-Agency RMBS	10	CPR		1	%		19.9	%		6.9	%
	-1	Data presented are weighted averages.
	The following tables present the activity of the instruments fair valued at Level 3 during the nine months ended September 30, 2013:
		Nine Months Ended
		September 30, 2013
		Level 3 Fair Values
		Non-Agency CMBS				Non-Agency RMBS				Other			Total assets
	Balance as of beginning of the period	$	100,102			$	5,118			$	25		$	105,245
	Purchases	26,021				—				—			26,021
	Sales/write-offs to net income	—				—				(25		)	(25		)
	Unrealized (loss) gain included in OCI	(4,706		)		(108		)		—			(4,814		)
	Principal payments	(21,731		)		(2,255		)		—			(23,986		)
	(Amortization) accretion	(61		)		33				—			(28		)
	Balance as of end of period	$	99,625			$	2,788			$	—		$	102,413
	The following table presents a summary of the recorded basis and estimated fair values of the Company’s financial instruments as of the periods indicated:
		September 30, 2013								December 31, 2012
		Recorded Basis				Fair Value				Recorded Basis			Fair Value
	Assets:
	Mortgage-backed securities	$	4,141,744			$	4,141,744			$	4,103,981		$	4,103,981
	Securitized mortgage loans, net	59,797				50,932				70,823			61,916
	Other investments	1,305				1,305				858			810
	Derivative assets	12,908				12,908				—			—
	Liabilities:
	Repurchase agreements	$	3,674,850			$	3,675,197			$	3,564,128		$	3,564,787
	Non-recourse collateralized financing	21,148				20,855				30,504			30,756
	Derivative liabilities	20,837				20,837				42,537			42,537
	There were no assets or liabilities which were measured at fair value on a non-recurring basis as of September 30, 2013 or December 31, 2012.

Shareholders_Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Shareholders' Equity	'
	SHAREHOLDERS' EQUITY
	Preferred Stock
	The Company declared its regular quarterly dividend of $0.53125 per share on its 8.50% Series A Cumulative Redeemable Preferred Stock and $0.4765625 per share on its 7.625% Series B Cumulative Redeemable Preferred Stock for the third quarter of 2013 payable on October 15, 2013 to shareholders of record as of October 7, 2013.
	Common Stock
	The following table presents a summary of the changes in the number of common shares outstanding since December 31, 2 012:
		2013
	Balance as of January 1, 2013	54,268,915
	Common stock issued under DRIP	509,831
	Common stock issued under ATM program	180,986
	Common stock issued or redeemed under stock and incentive plans	270,158
	Common stock forfeited for tax withholding on share-based compensation	(52,385	)
	Common stock repurchased during the period (weighted average price of $7.94 per share)	(751,456	)
	Balance as of September 30, 2013	54,426,049
	The Company has approximately 7,416,520 shares of common stock that remain available to offer and sell through its sales agent, JMP Securities LLC, under its "at the market", or "ATM" program, as of September 30, 2013. The Company did not issue any common shares under this program during the three months ended September 30, 2013.
	The Company's Dividend Reinvestment and Share Purchase Plan ("DRIP") allows registered shareholders to automatically reinvest some or all of their quarterly dividends in shares of the Company’s stock and provides an opportunity for investors to purchase shares of the Company’s stock, potentially at a discount to the prevailing market price. Of the 3,000,000 shares reserved for issuance under the Company's DRIP, there are 2,472,324 shares remaining for issuance as of September 30, 2013. The Company declared a third quarter common stock dividend of $0.27 per share payable on October 31, 2013 to shareholders of record as of October 7, 2013. There was no discount for shares purchased through the DRIP during the third quarter of 2013.
	Of the $50,000 authorized by the Company's Board of Directors for the repurchase of its common stock through December 31, 2014, approximately $43,115 remains available as of September 30, 2013.
	Incentive Plans.     Pursuant to the Company’s 2009 Stock and Incentive Plan, the Company may grant stock-based compensation to eligible employees, directors or consultants or advisers to the Company, including stock awards, stock options, SARs, dividend equivalent rights, performance shares, incentive awards, and restricted stock units.  Of the 2,500,000 shares of common stock authorized for issuance under this plan, 1,550,118 shares remain available for issuance as of September 30, 2013. Total stock-based compensation expense recognized by the Company for the three and nine months ended September 30, 2013 was $612 and $1,726, respectively, compared to $490 and $1,410, respectively, for the three and nine months ended September 30, 2012.
	The following table presents a rollforward of the restricted stock activity for the periods indicated:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Restricted stock outstanding as of beginning of period	526,803			454,117			448,283		365,506
	Restricted stock granted	—			—			255,158		220,821
	Restricted stock vested	(2,917	)		(2,917	)		(179,555	)	(135,127	)
	Restricted stock outstanding as of end of period	523,886			451,200			523,886		451,200
	The restricted stock granted during the nine months ended September 30, 2013 and September 30, 2012 had fair values of $2,708 and $2,073, respectively, at their grant dates. As of September 30, 2013, the balance of the Company’s outstanding restricted stock remaining to be amortized into compensation expense is $3,951 of which $640 is expected to be amortized in the remaining three months of 2013, $1,643 in 2014, $1,155 in 2015, $447 in 2016, and $66 in 2017.
	As of September 30, 2013, the Company also has 25,000 SARs outstanding which were granted pursuant to the Company's 2004 Stock Incentive Plan and are all vested and exercisable at their exercise price of $7.06 per share any time prior to their expiration date of December 31, 2013. No new awards may be granted under this plan. As of September 30, 2013 and December 31, 2012, the fair value of the Company’s outstanding SARs of $43 and $66, respectively, are recorded as liabilities on its consolidated balance sheet for the respective periods.
	Additional Paid-In Capital
	The following table presents a rollforward of the Company's changes in additional paid-in capital since December 31, 2012:
		2013
	Balance as of January 1, 2013	$	759,214
	Common stock issuances:
	DRIP issuances	5,401
	ATM issuances	1,954
	Incentive plans	147
	Adjustments related to tax withholding for share-based compensation	(545		)
	Common stock repurchases	(5,956		)
	Amortization of restricted stock, net of additional grants	1,736
	Capitalized expenses	(89		)
	Balance as of September 30, 2013	$	761,862
	Accumulated Other Comprehensive Income
	Accumulated other comprehensive income as of September 30, 2013 and December 31, 2012 is comprised of the following items:
		September 30, 2013				December 31, 2012
	Available for sale investments:
	Unrealized gains	$	49,669			$	104,869
	Unrealized losses	(72,057		)		(12,623		)
		(22,388		)		92,246
	Hedging instruments:
	Unrealized gains	3,779				—
	Unrealized losses	(15,754		)		(39,735		)
		(11,975		)		(39,735		)
	Accumulated other comprehensive income	$	(34,363	)		$	52,511
	Due to the Company’s REIT status, the items comprising other comprehensive income do not have related tax effects.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	The Company records accruals for certain outstanding legal proceedings, investigations or claims when it is probable that a liability will be incurred and the amount of the loss can be reasonably estimated. The Company evaluates, on a quarterly basis, developments in legal proceedings, investigations and claims that could affect the amount of any accrual, as well as any developments that would make a loss contingency both probable and reasonably estimable. When a loss contingency is not both probable and reasonably estimable, the Company does not accrue the loss. However, if the loss (or an additional loss in excess of the accrual) is at least a reasonable possibility and material, then the Company discloses a reasonable estimate of the possible loss or range of loss, if such reasonable estimate can be made. If the Company cannot make a reasonable estimate of the possible material loss, or range of loss, then that fact is disclosed.
	The Company and its subsidiaries are parties to various legal proceedings, including those described below.  Although the ultimate outcome of these legal proceedings cannot be ascertained at this time, and the results of legal proceedings cannot be predicted with certainty, the Company believes, based on current knowledge, that the resolution of any of these proceedings, including those described below, will not have a material effect on the Company’s consolidated financial condition or liquidity.  However, the resolution of any of the proceedings described below could have a material impact on consolidated results of operations or cash flows in a given future reporting period as the proceedings are resolved.
	One of the Company's subsidiaries, GLS Capital, Inc. (“GLS”), and the County of Allegheny, Pennsylvania ("Allegheny County") are defendants in a class action lawsuit filed in 1997 in the Court of Common Pleas of Allegheny County, Pennsylvania (the “Court”).  Between 1995 and 1997, GLS purchased from Allegheny County delinquent property tax lien receivables for properties located in the county.  The plaintiffs in this matter alleged that GLS improperly recovered or sought recovery for certain fees, costs, interest, and attorneys' fees and expenses in connection with GLS' collection of the property tax lien receivables.   The Court granted class action status and defined the class to include only owners of real estate in Allegheny County who paid an attorneys' fee between 1996 and 2003 in connection with the forced collection of delinquent property tax receivables by GLS (generally through the initiation of a foreclosure action).  Amendments to the statute that governs the collection of delinquent tax liens in Pennsylvania, related case law, and GLS' filing of one or more successful motions for summary judgment resulted in the dismissal of certain claims against GLS and narrowed the issues being litigated to whether attorneys' fees and related expenses charged by GLS in connection with the collection of the receivables were reasonable.  Such attorneys' fees and lien costs were assessed by GLS in its collection efforts pursuant to the prevailing Allegheny County ordinance.  On April 23, 2012, as a result of a petition to discontinue filed by the plaintiffs, the Court dismissed the remaining claim against GLS regarding the reasonableness of the attorney fees. Plaintiffs subsequently appealed the dismissal to the Pennsylvania Commonwealth Court of Appeals ("Court of Appeals"). The claims made by plaintiffs on appeal included only the legality of charging and recovering attorneys' fees and tax lien revival and assignment costs from the class members. Plaintiffs had never enumerated their damages in this matter. On July 15, 2013, the Court of Appeals affirmed the Court of Common Pleas' ruling allowing GLS to recover attorney's fees and lien revival and assignment fees from the class members.  According to the Court of Appeals, the named representative plaintiffs may recover the attorneys' fees they paid GLS in order to stop the foreclosure action but only one of the two named plaintiffs ever paid any attorney fees to GLS and the amount was less than $3. The Court of Appeals also affirmed the finding that revival and assignment are collection tools that may be utilized by GLS as an assignee of the County and such fees are properly collected from the delinquent taxpayers. Plaintiffs had the right to file an application for re-argument to the Court of Appeals or a Petition for Allowance of Appeal with the Supreme Court of Pennsylvania. Plaintiffs failed to apply for re-argument or petition for appeal with the Supreme Court of Pennsylvania within the allotted time period, and therefore the Company considers this matter resolved.
	The Company, GLS, and Allegheny County are named defendants in a putative class action lawsuit filed in June 2012 in the Court of Common Pleas of Allegheny County, Pennsylvania. The lawsuit relates to the activities of GLS in Allegheny County related to the purchase and collection of delinquent property tax lien receivables discussed above. The purported class in this action consists of owners of real estate in Allegheny County whose property is or has been subject to a tax lien filed by Allegheny County that Allegheny County either retained or sold to GLS and who were billed by Allegheny County or GLS for attorneys' fees, interest, and certain other fees and who sustained economic damages on and after August 14, 2003. The putative class allegations are that Allegheny County, GLS, and the Company violated the class's constitutional due process rights in connection with delinquent tax collection efforts. There are also allegations that amounts recovered from the class by GLS and / or Allegheny County are an unconstitutional taking of private property.  The claims against the Company are solely based upon its ownership of GLS. The complaint requests that the Court order GLS to account for amounts alleged to have been collected in violation of the putative class members' rights and create a constructive trust for the return of such amounts to members of the purported class. The Company believes the claims are without merit and intends to defend against them vigorously in this matter. The same class previously filed substantially the same lawsuit in 2004 against GLS and Allegheny County (ACORN v. County of Allegheny and GLS Capital, Inc.), and that cased was dismissed by the Court of Common Pleas with prejudice on June 28, 2013.
	The Company and DCI Commercial, Inc. ("DCI"), a former affiliate of the Company and formerly known as Dynex Commercial, Inc., are appellees (or respondents) in the matter of Basic Capital Management, Inc. et al.  (collectively, “BCM” or the “Plaintiffs”) versus DCI et al. currently pending in state court in Dallas, Texas.  The matter was initially filed in the state court in Dallas County, Texas in April 1999 against DCI, and in March 2000, BCM amended the complaint and added the Company as a defendant. Following a trial court decision in favor of both the Company and DCI, Plaintiffs appealed, seeking reversal of the trial court's judgment and rendition of judgment against the Company for alleged breach of loan agreements for tenant improvements in the amount of $250. Plaintiffs also sought reversal of the trial court's judgment and rendition of judgment against DCI in favor of BCM under two mutually exclusive damage models, for $2,200 and $25,600, respectively, related to the alleged breach by DCI of a $160,000 “master” loan commitment. Plaintiffs also sought reversal and rendition of a judgment in their favor for attorneys' fees in the amount of $2,100. Alternatively, Plaintiffs sought a new trial. On February 13, 2013, the Fifth Circuit Court of Appeals in Dallas, Texas (the “Fifth Circuit”) ruled on Plaintiff's appeal, affirming the previous decision of no liability with respect to the Company, and reversing the previous decision of no liability with respect to DCI relating to the $160,000 “master” loan commitment. The Fifth Circuit ordered a new trial to determine the amount of attorneys' fees and prejudgment and post-judgment interest due to Plaintiffs and reinstated the $25,600 damage award against DCI. On May 22, 2013, the Fifth Circuit vacated its order on February 13, 2013 and remanded the case to the trial court for entry of judgment against DCI and for a new trial with respect to attorney's fees and for costs and pre-judgment and post-judgment interest as determined by the trial court. The Fifth Circuit also affirmed the trial court's decision with respect to a take nothing judgment against the Company. DCI has appealed the matter to the Supreme Court of Texas to reverse the $25,600 damage award. Management believes the Company will not be obligated for any amounts that may ultimately be awarded against DCI.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	SUBSEQUENT EVENTS
	Management has evaluated events and circumstances occurring as of and through the date this Quarterly Report on Form 10-Q was filed with the SEC and has determined that there have been no significant events or circumstances that qualify as a "recognized" subsequent event as defined by ASC Topic 855. Management has determined that the following events or circumstances qualify as "nonrecognized" subsequent events as defined by ASC Topic 855:
	Effective October 1, 2013, the Company amended its master repurchase agreement with Wells Fargo Bank, N.A. to extend the termination date to August 6, 2015 and increase the aggregate maximum borrowing capacity to $250,000.
	Subsequent to September 30, 2013, the Company terminated interest rate swaps with a combined notional of $902,000.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation [Policy Text Block]	'
	Basis of Presentation
	The accompanying consolidated financial statements of Dynex Capital, Inc. and its qualified real estate investment trust (“REIT”) subsidiaries and its taxable REIT subsidiary (together, “Dynex” or the “Company”) have been prepared in accordance with the instructions to the Quarterly Report on Form 10-Q and Article 10, 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 notes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements.  The financial information included herein is unaudited; however, in the opinion of management, all significant adjustments, consisting of normal recurring accruals considered necessary for a fair presentation of the consolidated financial statements, have been included.  Operating results for the three and nine months ended September 30, 2013 are not necessarily indicative of the results that may be expected for any other interim periods or for the entire year ending December 31, 2013.  The unaudited consolidated financial statements included herein should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012 filed with the SEC.
	Certain items in the prior years' consolidated financial statements have been reclassified to conform to the current year’s presentation.  The Company’s consolidated balance sheet as of December 31, 2012 now presents its Agency and non-Agency mortgage-backed securities as "mortgage-backed securities, at fair value". The Company's consolidated statements of income for the three and nine months ended September 30, 2012 now present interest income from Agency and non-Agency mortgage-backed securities together as "interest income: mortgage-backed securities". In addition, changes in fair value and other activity related to the Company's derivative instruments have been reclassified from "fair value adjustments, net" to "gain (loss) on derivative instruments, net". As a result, the respective amounts on the Company's consolidated statement of cash flows for the nine months ended September 30, 2012 have been changed to reflect this reclassification. These presentation changes have no effect on reported total assets, total liabilities, results of operations, or cash flow activities.
Consolidation [Policy Text Block]	'
	Consolidation
	The consolidated financial statements include the accounts of the Company, its qualified REIT subsidiaries and its taxable REIT subsidiary.  The consolidated financial statements represent the Company’s accounts after the elimination of intercompany balances and transactions.  The Company consolidates entities in which it owns more than 50% of the voting equity and control does not rest with others and variable interest entities in which it is determined to be the primary beneficiary in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 810-10.  The Company follows the equity method of accounting for investments in which it owns greater than a 20% and less than 50% interest in partnerships and corporate joint ventures or when it is able to influence the financial and operating policies of the investee but owns less than 50% of the voting equity.
	In accordance with ASC Topic 810-10, the Company also consolidates certain trusts through which it has securitized mortgage loans. Additional information regarding the accounting policy for securitized mortgage loans is provided below under "Investments".
Use of Estimates [Policy Text Block]	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenue and expenses during the reported period.  Actual results could differ from those estimates.  The most significant estimates used by management include but are not limited to fair value measurements of its investments, allowance for loan losses, other-than-temporary impairments, contingencies, and amortization of premiums and discounts. These items are discussed further below within this note to the consolidated financial statements.
Federal Income Taxes [Policy Text Block]	'
	Federal Income Taxes
	The Company believes it has complied with the requirements for qualification as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”).  As such, the Company believes that it qualifies as a REIT for federal income tax purposes, and it generally will not be subject to federal income tax on the amount of its income or gain that is distributed as dividends to shareholders.  The Company uses the calendar year for both tax and financial reporting purposes.  There may be differences between taxable income and income computed in accordance with GAAP.
Cash and Cash Equivalents [Policy Text Block]	'
	Cash and Cash Equivalents
	Cash and cash equivalents include cash on hand and highly liquid investments with original maturities of three months or less.
Restricted Cash [Policy Text Block]	'
	Restricted Cash
	Restricted cash consists of cash the Company has pledged to cover initial and variation margin with its counterparties.
Investments [Policy Text Block]	'
	Restricted Cash
	Restricted cash consists of cash the Company has pledged to cover initial and variation margin with its counterparties.
	Investments
	The Company’s investments include Agency mortgage-backed securities ("MBS"), non-Agency MBS, securitized mortgage loans, and other investments.
	Agency MBS. The Company accounts for its investment in Agency MBS in accordance with ASC Topic 320, which requires that investments in debt and equity securities be designated at the time of acquisition as either “held-to-maturity,” “available-for-sale” or “trading”.  As of September 30, 2013, the majority of the Company's Agency MBS are designated as available-for-sale (or "AFS") with the remainder designated as trading.  Although the Company generally intends to hold its available-for-sale securities until maturity, it may, from time to time, sell any of these securities as part of the overall management of its business.  The available-for-sale designation provides the Company with this flexibility.
	All of the Company’s Agency MBS are recorded at their fair value on the consolidated balance sheet. In accordance with ASC Topic 820, the Company determines the fair value of its Agency MBS based upon prices obtained from a third-party pricing service and broker quotes. The Company's application of ASC Topic 820 guidance is discussed further in Note 7. Changes in the fair value of Agency MBS designated as trading are recognized in net income within “fair value adjustments, net”.  Gains and losses realized upon the sale, impairment, or other disposal of a trading security are also recognized within “fair value adjustments, net”.  Alternatively, changes in the fair value of Agency MBS designated as available-for-sale are reported in other comprehensive income as unrealized gains (losses) until the security is collected, disposed of, or determined to be other than temporarily impaired.  Upon the sale of an available-for-sale security, any unrealized gain or loss is reclassified out of accumulated other comprehensive income (“AOCI”) into net income as a realized “gain (loss) on sale of investments, net” using the specific identification method.
	Non-Agency MBS.  The Company accounts for its investment in non-Agency MBS in accordance with ASC Topic 320.  As of September 30, 2013, all of the Company’s non-Agency MBS are designated as available-for-sale and are recorded at their fair value on the consolidated balance sheet.  Changes in fair value are reported in other comprehensive income until the security is collected, disposed of, or determined to be other than temporarily impaired. Like Agency MBS, the Company generally intends to hold its investments in non-Agency MBS until maturity, but it may, from time to time sell any of these securities as part of the overall management of its business.  Upon the sale of an available-for-sale security, any unrealized gain or loss is reclassified out of AOCI into net income as a realized “gain (loss) on sale of investments, net” using the specific identification method.
	In accordance with ASC Topic 820, the Company determines the fair value for the majority of its non-Agency MBS based upon prices obtained from a third-party pricing service and broker quotes.  The remainder of the non-Agency MBS are valued by discounting the estimated future cash flows derived from cash flow models that utilize information such as the security’s coupon rate, estimated prepayment speeds, expected weighted average life, collateral composition, estimated future interest rates, expected losses, credit enhancement, as well as certain other relevant information. The Company's application of ASC Topic 820 guidance is discussed further in Note 7.
	Other-than-Temporary Impairment. The Company evaluates all MBS in its investment portfolio for other-than-temporary impairments by applying the guidance prescribed in ASC Topic 320-10. The Company compares the amortized cost of each security in an unrealized loss position against the present value of expected future cash flows of the security. If there has been a significant adverse change in the cash flow expectations for a security resulting in its amortized cost becoming greater than the present value of its expected future cash flows, an other-than-temporary credit impairment has occurred. If the Company does not intend to sell and is not more likely than not required to sell the security, the credit loss is recognized in earnings and the balance of the unrealized loss is recognized in other comprehensive income (loss). If the Company intends to sell the security or will be more likely than not required to sell the security, the full unrealized loss is recognized in earnings.
	In periods after the recognition of an other-than-temporary impairment loss for MBS, the Company shall account for the other-than-temporarily impaired MBS as if the MBS had been purchased on the measurement date of the other-than-temporary impairment at an amortized cost basis equal to the previous amortized cost basis less the other-than-temporary impairment recognized in earnings. For MBS for which other-than-temporary impairments were recognized in earnings, the difference between the new amortized cost basis and the cash flows expected to be collected shall be accreted into interest income using the effective interest method. The Company shall continue to estimate the present value of cash flows expected to be collected over the life of the MBS. For all other MBS, if upon subsequent evaluation, there is an increase in the cash flows expected to be collected or if actual cash flows are greater than cash flows previously expected, such changes shall be accounted for as a prospective adjustment to the accretable yield in accordance with Subtopic 310-30 even if the MBS would not otherwise be within the scope of that Subtopic. Subsequent increases and decreases in the fair value of the MBS that are not other-than-temporary shall be included in other comprehensive inc
Securitized Mortgage Loans, Other Investments [Policy Text Block]	'
	Securitized Mortgage Loans.  Securitized mortgage loans consist of loans pledged to support the repayment of securitization financing bonds issued by the Company. The associated securitization financing bonds are treated as debt of the Company and are presented as a portion of "non-recourse collateralized financing" on the consolidated balance sheet. In accordance with ASC Topic 310-10, the Company's securitized mortgage loans are reported at amortized cost.  Securitized mortgage loans can only be sold subject to the lien of the respective securitization financing indenture. An allowance has been established for currently existing and probable losses on such loans as further discussed below.
	Other Investments.  Other investments include unsecuritized mortgage loans owned by the Company as well as the Company's investment in a limited partnership that invests in pools of non-qualifying mortgage loans. The Company accounts for its other investments using the cost method in accordance with ASC Topic 325-20.
Allowance for Loan Losses [Policy Text Block]	'
	Allowance for Loan Losses. An allowance for loan losses has been estimated and established for currently existing and probable losses for securitized and unsecuritized mortgage loans that are considered impaired in accordance with ASC Topic 310-10.  Provisions made to increase the allowance are charged as a current period expense.  Commercial mortgage loans are secured by income-producing real estate and are evaluated individually for impairment when the debt service coverage ratio on the mortgage loan is less than 1:1 or when the mortgage loan is delinquent.  Commercial mortgage loans not evaluated for individual impairment are evaluated for a general allowance.  Certain of the commercial mortgage loans are covered by mortgage loan guarantees that limit the Company’s exposure on these mortgage loans.  Single-family mortgage loans are considered homogeneous and are evaluated on a pool basis for a general allowance.
	The Company considers various factors in determining its specific and general allowance requirements, including whether a loan is delinquent, the Company’s historical experience with similar types of loans, historical cure rates of delinquent loans, and historical and anticipated loss severity of the mortgage loans as they are liquidated.  The factors may differ by mortgage loan type (e.g., single-family versus commercial) and collateral type (e.g., multifamily versus office property).  The allowance for loan losses is evaluated and adjusted periodically by management based on the actual and estimated timing and amount of probable credit losses, using the above factors, as well as industry loss experience.
Repurchase Agreements [Policy Text Block]	'
	Repurchase Agreements
	Repurchase agreements are treated as financings in accordance with the provision of ASC Topic 860 under which the Company pledges its securities as collateral to secure a loan, which is equal in value to a specified percentage of the estimated fair value of the pledged collateral. The Company retains beneficial ownership of the pledged collateral.  At the maturity of a repurchase agreement, the Company is required to repay the loan and concurrently receives back its pledged collateral from the lender or, with the consent of the lender, the Company may renew the agreement at the then prevailing financing rate.  A repurchase agreement lender may require the Company to pledge additional collateral in the event of a decline in the fair value of the collateral pledged.  Repurchase agreement financing is recourse to the Company and the assets pledged.  Most of the Company’s repurchase agreements are based on the September 1996 version of the Bond Market Association Master Repurchase Agreement, which generally provides that the lender, as buyer, is responsible for obtaining collateral valuations from a generally recognized source agreed to by both the Company and the lender, or, in an instance when such source is not available, the value determination is made by the lender.
Derivative Instruments [Policy Text Block]	'
	Derivative Instruments
	The Company accounts for its derivative instruments in accordance with ASC Topic 815. ASC Topic 815 requires an entity to recognize all derivatives as either assets or liabilities in the balance sheet and to measure those instruments at fair value.
	Effective June 30, 2013, the Company discontinued hedge accounting for derivative instruments which had previously been accounted for as cash flow hedges under ASC Topic 815. Activity up to and including June 30, 2013 for those agreements previously designated as cash flow hedges was recorded in accordance with cash flow hedge accounting as prescribed by ASC Topic 815, which states that the effective portion of the hedge relationship on an instrument designated as a cash flow hedge is reported in the current period's other comprehensive income while the ineffective portion is immediately reported in the current period’s consolidated statement of income. The balance remaining in AOCI related to the de-designated cash flow hedges is being recognized in the Company's consolidated statement of income as a portion of "interest expense" over the remaining life of the interest rate swap agreements. Subsequent to June 30, 2013 changes in the fair value of the Company's derivative instruments, plus periodic settlements, are recorded in the Company's consolidated statement of income as a portion of "(loss) gain on derivative instruments, net".
	The Company has Eurodollar futures, which are valued based on closing exchange prices. Variation margin is exchanged daily to settle any changes in the value of the Eurodollar futures. Gains and losses associated with purchases and short sales of futures contracts are reported in "(loss) gain on derivative instruments, net", in our consolidated statements of income.
	The Company has elected to use the portfolio exception in ASC 820-10-35-18D with respect to measuring counterparty credit risk for derivative instruments. The Company manages credit risk for its derivative positions on a counterparty-by-counterparty basis (that is, on the basis of its net portfolio exposure with each counterparty), consistent with its risk management strategy for such transactions. The Company manages credit risk by considering indicators of risk such as credit ratings, and by negotiating terms in its ISDA master netting arrangements and, if applicable, any associated Credit Support Annex documentation, with each individual counterparty. Since the effective date of ASC 820, management has monitored and measured credit risk and calculated credit valuation adjustments for its derivative transactions on the basis of its relationships at the counterparty portfolio level. Management receives reports from an independent third-party valuation specialist on a monthly basis providing the credit valuation adjustments at the counterparty portfolio level for purposes of reviewing and managing its credit risk exposures. Since the portfolio exception applies only to the fair value measurement and not to financial statement presentation, the portfolio-level adjustments are then allocated in a reasonable and consistent manner each period to the individual assets or liabilities that make up the group, in accordance with other applicable accounting guidance and the Company's accounting policy elections.
	Although MBS have characteristics that meet the definition of a derivative instrument, ASC 815 specifically excludes these instruments from its scope because they are accounted for as debt securities under ASC 320.
Interest Income, Premium Amortization, and Discount Accretion [Policy Text Block]	'
	Interest Income, Premium Amortization, and Discount Accretion
	Interest income is accrued based on the outstanding principal balance (or notional balance in the case of interest-only, or "IO", securities) on the Company's investment securities and their contractual terms. Premiums and discounts on Agency and non-Agency MBS and on loans are recognized over the expected life of the investment using the effective yield method in accordance with ASC Topic 310-20. Adjustments to premium amortization are made for actual prepayment activity as well as changes in projected future cash flows in accordance with 320-10. Interest income on non-Agency MBS that are rated lower than “AA” are recognized over the expected life as adjusted for the estimated prepayments and credit losses of the securities.  Actual prepayment and any credit losses experienced are compared to projected prepayments and credit losses, and effective yields are adjusted when those amounts differ.
	The Company's projections of future cash flows are based on input and analysis received from external sources and internal models, and includes assumptions about the amount and timing of credit losses, loan prepayment rates, fluctuations in interest rates, and other factors. On at least a quarterly basis, the Company reviews and makes any necessary adjustments to its cash flow projections and updates the yield recognized on these assets.
	For securities, the accrual of interest is discontinued when, in the opinion of management, it is probable that all amounts contractually due will not be collected, and in certain instances, as a result of the other-than-temporary impairment analysis. For loans, the accrual of interest is discontinued when, in the opinion of management, the interest is not collectible in the normal course of business, when the loan is significantly past due or when the primary servicer of the loan fails to advance the interest and/or principal due on the loan.  Loans are considered past due when the borrower fails to make a timely payment in accordance with the underlying loan agreement.  All interest accrued but not collected for investments that are placed on a non-accrual status or are charged-off is reversed against interest income.  Interest on these investments is accounted for on the cash-basis or cost-recovery method until qualifying for return to accrual status.  Investments are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured.
Stock-based Compensation [Policy Text Block]	'
	Stock-Based Compensation
	Pursuant to the Company’s 2009 Stock and Incentive Plan ("SIP"), the Company may grant stock-based compensation to eligible employees, directors or consultants or advisers to the Company, including stock awards, stock options, stock appreciation rights (“SARs”), dividend equivalent rights, performance shares, and restricted stock units.  Currently, the Company's stock options and restricted stock issued under this plan may be settled only in shares of its common stock, and therefore are treated as equity awards with their fair value measured at the grant date as required by ASC Topic 718. Outstanding SARs issued by the Company may be settled only in cash, and therefore have been treated as liability awards with their fair value estimated at the grant date and remeasured at the end of each reporting period using the Black-Scholes option valuation model as required by ASC Topic 718.  Please see Note 8 for additional disclosures regarding the Company's SIP.
Contingencies [Policy Text Block]	'
	Contingencies
	In the normal course of business, there are various lawsuits, claims, and other contingencies pending against the Company.  We evaluate whether to establish provisions for estimated losses from those matters in accordance with ASC Topic 450, which states that a liability is recognized for a contingent loss when: (a) the underlying causal event has occurred prior to the balance sheet date; (b) it is probable that a loss has been incurred; and (c) there is a reasonable basis for estimating that loss. A liability is not recognized for a contingent loss when it is only possible or remotely possible that a loss has been incurred, however, possible contingent losses shall be disclosed. Please refer to Note 9 for details on the most significant matters currently pending.
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	'
	Recent Accounting Pronouncements
	In July 2013, the FASB issued ASU 2013-10, Derivatives and Hedging (Topic 815), Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes(a consensus of the FASB Emerging Issues Task Force) ("ASU 2013-10"). The new guidance permits the use of the Federal Funds Effective Swap Rate as a benchmark interest rate for hedge accounting purposes and removes certain restrictions on being able to apply hedge accounting for similar hedges using different benchmark interest rates. ASU 2013-10 is effective prospectively for qualifying new or re-designated hedging relationships entered into on or after July 17, 2013. The adoption of this ASU does not have an impact on our derivatives and will not have a material impact on the Company's consolidated financial statements.
	In June 2013, the FASB issued ASU 2013-08, Financial Services - Investment Companies: Amendments to the Scope, Measurement, and Disclosure Requirements ("ASU 2013-08"). In general, the amendments of this ASU: (i) revise the definition of an investment company; (ii) require an investment company to measure non-controlling ownership interests in other investment companies at fair value rather than using the equity method of accounting; and (iii) require information to be disclosed concerning the status of the entity and any financial support provided, or contractually required to be provided, by the investment company to its investees. ASU 2013-08 is effective for interim and annual periods that begin after December 15, 2013 and early application is prohibited. As the FASB has decided to retain the current U.S. GAAP scope exception from investment company accounting and financial reporting for real estate investment trusts, the adoption of this ASU will not have a material impact on the Company's consolidated financial statements.

Net_Income_Per_Common_Share_Ta

Net Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share, Basic and Diluted [Abstract]	'
Schedule of Calculation of Numerator and Denominator in Net Income Per Common Share [Table Text Block]	'
	The following table presents the calculation of the numerator and denominator for both basic and diluted net (loss) income per common share:
		Three Months Ended
		September 30,
		2013						2012
		Net Loss			Weighted-Average Common Shares			Net			Weighted-
								Income			Average
											Common
											Shares
	Net (loss) income	$	(4,627	)				$	19,167
	Preferred stock dividends	(2,294		)				(814		)
	Net (loss) income to common shareholders	(6,921		)	54,903,637			18,353			54,367,349
	Effect of dilutive stock options	—			—			—			866
	Diluted	$	(6,921	)	54,903,637			$	18,353		54,368,215
	Net (loss) income per common share:
	Basic				$	(0.13	)				$	0.34
	Diluted				$	(0.13	)				$	0.34
		Nine Months Ended
		September 30,
		2013						2012
		Net			Weighted-Average Common Shares			Net			Weighted-
		Income						Income			Average
											Common
											Shares
	Net income	$	46,510					$	54,489
	Preferred stock dividends	(5,608		)				(814		)
	Net income to common shareholders	40,902			54,727,950			53,675			52,751,763
	Effect of dilutive stock options	—			—			—			—
	Diluted	$	40,902		54,727,950			$	53,675		52,751,763
	Net income per common share:
	Basic				$	0.75					$	1.02
	Diluted (1)				$	0.75					$	1.02
	-1	For the nine months ended September 30, 2012, the calculation of diluted net income per common share excludes the effect of 15,000 unexercised stock option awards because their inclusion would have been anti-dilutive.

Mortgage_Backed_Securities_Mor1

Mortgage Backed Securities Mortgage backed securities (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Available-for-sale Securities [Line Items]	'
Available-for-sale Securities [Table Text Block]	'
	The following table presents the components of the Company’s MBS designated as AFS as of September 30, 2013 and December 31, 2012:
		September 30, 2013
		Par		Net Premium (Discount)			Amortized Cost				Net Unrealized Gain (Loss)				Fair Value			Weighted average coupon
	Agency:
	RMBS	$	2,723,084	$	162,370		$	2,885,454			$	(56,407	)		$	2,829,047		3.26	%
	CMBS	261,440		19,844			281,284				11,941				293,225			4.82	%
	CMBS IO (1)	—		466,494			466,494				9,114				475,608			0.89	%
	Total Agency AFS:	2,984,524		648,708			3,633,232				(35,352		)		3,597,880
	Non-Agency:
	RMBS	14,972		(351		)	14,621				(33		)		14,588			4.58	%
	CMBS	381,342		(17,213		)	364,129				10,620				374,749			5.52	%
	CMBS IO (1)	—		123,172			123,172				2,377				125,549			0.87	%
	Total non-Agency AFS:	396,314		105,608			501,922				12,964				514,886
	Total AFS securities	$	3,380,838	$	754,316		$	4,135,154			$	(22,388	)		$	4,112,766
	-1	The notional balance for Agency CMBS IO and non-Agency CMBS IO is $9,682,065 and $2,857,343, respectively, as of September 30, 2013.
		31-Dec-12
		Par		Net Premium (Discount)			Amortized Cost				Net Unrealized Gain (Loss)				Fair Value			Weighted average coupon
	Agency:
	RMBS	$	2,425,826	$	137,168		$	2,562,994			$	8,343			$	2,571,337		3.67	%
	CMBS	280,602		21,907			302,509				21,564				324,073			5.19	%
	CMBS IO (1)	—		550,171			550,171				17,009				567,180			0.95	%
	Total Agency AFS:	2,706,428		709,246			3,415,674				46,916				3,462,590
	Non-Agency:
	RMBS	11,411		(781		)	10,630				408				11,038			4.28	%
	CMBS	463,747		(17,313		)	446,434				39,908				486,342			5.31	%
	CMBS IO (1)	—		108,928			108,928				5,014				113,942			0.86	%
	Total non-Agency AFS:	475,158		90,834			565,992				45,330				611,322
	Total AFS securities	$	3,181,586	$	800,080		$	3,981,666			$	92,246			$	4,073,912
	-1	The notional balance for the Agency CMBS IO and non-Agency CMBS IO is $10,059,495 and $2,393,614, respectively, as of December 31, 2012.
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]	'
	The following table presents certain information for those Agency MBS in an unrealized loss position as of September 30, 2013 and December 31, 2012:
		30-Sep-13							31-Dec-12
		Fair Value		Gross Unrealized Losses			# of Securities		Fair Value				Gross Unrealized Losses				# of Securities
	Continuous unrealized loss position for less than 12 months:
	Agency MBS	$	2,129,694	$	(48,337	)	164		$	1,026,277			$	(6,552	)		83
	Non-Agency MBS	126,846		(5,902		)	23		13,877				(76		)		3
	Continuous unrealized loss position for 12 months or longer:
	Agency MBS	$	558,070	$	(17,718	)	67		$	271,719			$	(5,797	)		34
	Non-Agency MBS	1,820		(100		)	6		2,701				(198		)		8

Repurchase_Agreements_Repurcha

Repurchase Agreements Repurchase Agreements (Tables)	9 Months Ended
	Sep. 30, 2013
Transfers and Servicing [Abstract]	'
Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table Text Block]	'
	The following tables present the components of the Company’s repurchase agreements as of September 30, 2013 and December 31, 2012 by the fair value and type of securities pledged as collateral to the repurchase agreements:
		September 30, 2013
	Collateral Type	Balance			Weighted		Fair Value of
					Average Rate		Collateral Pledged
	Agency RMBS	$	2,634,120		0.41	%	2,721,562
	Agency CMBS	234,633			0.39	%	294,556
	Agency CMBS IOs	377,977			1.17	%	463,894
	Non-Agency RMBS	10,932			1.8	%	13,616
	Non-Agency CMBS	298,548			1.29	%	364,977
	Non-Agency CMBS IO	97,584			1.68	%	125,539
	Securitization financing bonds	21,403			1.6	%	24,853
	Deferred costs	(347		)	n/a		n/a
		$	3,674,850		0.59	%	$	4,008,997
		December 31, 2012
	Collateral Type	Balance			Weighted		Fair Value of Collateral Pledged
					Average Rate
	Agency RMBS	$	2,365,982		0.48	%	$	2,458,200
	Agency CMBS	248,771			0.47	%	291,445
	Agency CMBS IOs	443,540			1.22	%	565,494
	Non-Agency RMBS	7,808			1.84	%	9,634
	Non-Agency CMBS	382,352			1.34	%	465,306
	Non-Agency CMBS IOs	88,221			1.46	%	113,942
	Securitization financing bonds	28,113			1.64	%	31,483
	Deferred costs	(659		)	n/a		n/a
		$	3,564,128		0.7	%	$	3,935,504
Repurchase Agreements, Original Maturity Schedule [Table Text Block]	'
	Company has been able to extend the maturity dates for its repurchase agreements due to discontinuing cash flow hedge accounting. The following table provides a summary of the original maturities as of September 30, 2013 and December 31, 2012:
	Original Maturity	September 30,			December 31,
		2013			2012
	30 days or less	$	486,150		$	622,957
	31 to 60 days	677,725			1,263,105
	61 to 90 days	333,007			298,660
	91 to 120 days	1,021,594			1,092,681
	121 to 150 days	583,888			—
	Greater than 150 days	572,833			287,384
		$	3,675,197		$	3,564,787

Derivatives_Tables

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	'
	The table below summarizes information about the Company’s derivative instruments on its consolidated balance sheet as of the dates indicated:
					September 30, 2013
	Type of Derivative Instrument	Accounting Designation		Balance Sheet Location:	Fair Value			Aggregate Notional Amount
	Interest rate swaps	Non-hedging		Derivative assets	$	12,908		$	425,000
	Interest rate swaps	Non-hedging			$	(20,837	)	$	1,267,000
	Eurodollar futures	Non-hedging			—			20,250,000
				Derivative liabilities	$	(20,837	)	$	21,517,000
					31-Dec-12
	Type of Derivative Instrument	Accounting Designation		Balance Sheet Location:	Fair Value			Aggregate Notional Amount
	Interest rate swaps	Hedging			$	(39,813	)	$	1,435,000
	Interest rate swaps	Non-hedging			(2,724		)	27,000
				Derivative liabilities	$	(42,537	)	$	1,462,000
	(1) Margin requirements from fluctuations in fair value of the Company's Eurodollar futures are settled daily with counterparties.
Description of Derivative Activity Volume	'Information related to the volume of activity for our interest rate derivative instruments subsequent to December 31, 2012 is as follows:(amounts in thousands)Interest Rate Swaps Eurodollar FuturesNotional amount as of December 31, 2012:$1,462,000 $—Additions:380,000 22,100,000Settlements, terminations, or expirations:(150,000) (1,850,000)Notional amount as of September 30, 2013:(1)$1,692,000 $20,250,000(1)The Eurodollar futures notional amount as of September 30, 2013 represents the total notional of the 3-month contracts with expiration dates from 2013 to 2020. The maximum notional outstanding for any 3-month period does not exceed $1,275,000.
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	'
	The following table summarizes the contractual maturities remaining for the Company’s outstanding interest rate swap agreements as of September 30, 2013:
	Remaining	Notional Amount:			Weighted-Average
	Maturity	Trading			Fixed Rate Swapped
	0-12 months	$	435,000		1.26	%
	13-24 months	130,000			2.06	%
	25-36 months	260,000			1.96	%
	37-48 months	212,000			0.01	%
	49-60 months	15,000			2.17	%
	61-72 months	385,000			1.58	%
	73-84 months	25,000			1.61	%
	109-127 months	230,000			2.27	%
		$	1,692,000		1.64	%
Schedule of Derivative Instruments Included in Trading Activities [Table Text Block]	'
	The tables below summarize the effect of the Company's interest rate derivatives reported in "(loss) gain on derivative instruments, net" on the Company's consolidated statements of income for the periods indicated:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
	Type of Derivative Instrument	2013			2012			2013			2012
	Interest rate swaps	$	(6,225	)	$	(333	)	$	5,111		$	(907	)
	Eurodollar futures	(17,794		)	—			(17,794		)	—
	Loss on derivative instruments, net	$	(24,019	)	$	(333	)	$	(12,683	)	$	(907	)

Offsetting_Assets_and_Liabilit1

Offsetting Assets and Liabilities Offsetting Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Offsetting Assets [Line Items]	'
Offsetting Assets [Table Text Block]	'
		Offsetting of Assets
		Gross Amount of Recognized Assets		Gross Amount Offset in the Balance Sheet		Net Amount of Assets Presented in the Balance Sheet		Gross Amount Not Offset in the Balance Sheet						Net Amount
								Financial Instruments Received as Collateral			Cash Received as Collateral
	30-Sep-13
	Derivative assets	$	12,908	$	—	$	12,908	$	(1,689	)	$	(11,219	)	$	—
	December 31, 2012:
	Derivative assets	$	—	$	—	$	—	$	—		$	—		$	—

Offsetting_Assets_and_Liabilit2

Offsetting Assets and Liabilities Offsetting Liabilities (Tables)	9 Months Ended
	Sep. 30, 2013
Offsetting Liabilities [Line Items]	'
Offsetting Liabilities [Table Text Block]	'
		Offsetting of Liabilities
		Gross Amount of Recognized Liabilities		Gross Amount Offset in the Balance Sheet		Net Amount of Liabilities Presented in the Balance Sheet		Gross Amount Not Offset in the Balance Sheet						Net Amount
								Financial Instruments Posted as Collateral			Cash Posted as Collateral
	30-Sep-13
	Derivative liabilities	$	20,837	$	—	$	20,837	$	(20,175	)	$	(490	)	$	172
	Repurchase agreements	3,674,850		—		3,674,850		(3,674,850		)	—			—
		$	3,695,687	$	—	$	3,695,687	$	(3,695,025	)	$	(490	)	$	172
	December 31, 2012:
	Derivative liabilities	$	42,537	$	—	$	42,537	$	(42,499	)	$	(38	)	$	—
	Repurchase agreements	3,564,128		—		3,564,128		(3,564,128		)	—			—
		$	3,606,665	$	—	$	3,606,665	$	(3,606,627	)	$	(38	)	$	—

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	'
	The following table presents the fair value of the Company’s assets and liabilities, segregated by the hierarchy level of the fair value estimate, that are measured at fair value on a recurring basis as of the periods indicated:
		September 30, 2013
		Fair Value				Level 1 - Unadjusted Quoted Prices in Active Markets				Level 2 - Observable Inputs			Level 3 - Unobservable Inputs
	Assets:
	Mortgage-backed securities	$	4,141,744			$	—			$	4,039,331		$	102,413
	Derivative assets	12,908				—				12,908			—
	Total assets carried at fair value	$	4,154,652			$	—			$	4,052,239		$	102,413
	Liabilities:
	Derivative liabilities	$	20,837			$	—			$	20,837		$	—
	Total liabilities carried at fair value	$	20,837			$	—			$	20,837		$	—
		December 31, 2012
		Fair Value				Level 1 - Unadjusted Quoted Prices in Active Markets				Level 2 - Observable Inputs			Level 3 - Unobservable Inputs
	Assets:
	Mortgage-backed securities	$	4,103,981			$	—			$	3,998,761		$	105,220
	Other investments	25				—				—			25
	Total assets carried at fair value	$	4,104,006			$	—			$	3,998,761		$	105,245
	Liabilities:
	Derivative liabilities	$	42,537			$	—			$	42,537		$	—
	Total liabilities carried at fair value	$	42,537			$	—			$	42,537		$	—
Fair Value Inputs, Assets, Quantitative Information [Table Text Block]	'
	The table below presents information about the significant unobservable inputs used in the fair value measurement for the Company's Level 3 non-Agency CMBS and RMBS as of September 30, 2013:
		Quantitative Information about Level 3 Fair Value Measurements(1)
		Prepayment Speed			Default Rate			Severity			Discount Rate
	Non-Agency CMBS	20 CPY			2.5	%		35	%		6.5	%
	Non-Agency RMBS	10	CPR		1	%		19.9	%		6.9	%
	-1	Data presented are weighted averages.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	'
	The following tables present the activity of the instruments fair valued at Level 3 during the nine months ended September 30, 2013:
		Nine Months Ended
		September 30, 2013
		Level 3 Fair Values
		Non-Agency CMBS				Non-Agency RMBS				Other			Total assets
	Balance as of beginning of the period	$	100,102			$	5,118			$	25		$	105,245
	Purchases	26,021				—				—			26,021
	Sales/write-offs to net income	—				—				(25		)	(25		)
	Unrealized (loss) gain included in OCI	(4,706		)		(108		)		—			(4,814		)
	Principal payments	(21,731		)		(2,255		)		—			(23,986		)
	(Amortization) accretion	(61		)		33				—			(28		)
	Balance as of end of period	$	99,625			$	2,788			$	—		$	102,413
Recorded basis and fair value [Table Text Block]	'
	The following table presents a summary of the recorded basis and estimated fair values of the Company’s financial instruments as of the periods indicated:
		September 30, 2013								December 31, 2012
		Recorded Basis				Fair Value				Recorded Basis			Fair Value
	Assets:
	Mortgage-backed securities	$	4,141,744			$	4,141,744			$	4,103,981		$	4,103,981
	Securitized mortgage loans, net	59,797				50,932				70,823			61,916
	Other investments	1,305				1,305				858			810
	Derivative assets	12,908				12,908				—			—
	Liabilities:
	Repurchase agreements	$	3,674,850			$	3,675,197			$	3,564,128		$	3,564,787
	Non-recourse collateralized financing	21,148				20,855				30,504			30,756
	Derivative liabilities	20,837				20,837				42,537			42,537

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Schedule of Common Stock Outstanding Roll Forward [Table Text Block]	'
	The following table presents a summary of the changes in the number of common shares outstanding since December 31, 2 012:
		2013
	Balance as of January 1, 2013	54,268,915
	Common stock issued under DRIP	509,831
	Common stock issued under ATM program	180,986
	Common stock issued or redeemed under stock and incentive plans	270,158
	Common stock forfeited for tax withholding on share-based compensation	(52,385	)
	Common stock repurchased during the period (weighted average price of $7.94 per share)	(751,456	)
	Balance as of September 30, 2013	54,426,049
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	'
	The following table presents a rollforward of the restricted stock activity for the periods indicated:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Restricted stock outstanding as of beginning of period	526,803			454,117			448,283		365,506
	Restricted stock granted	—			—			255,158		220,821
	Restricted stock vested	(2,917	)		(2,917	)		(179,555	)	(135,127	)
	Restricted stock outstanding as of end of period	523,886			451,200			523,886		451,200
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	Accumulated other comprehensive income as of September 30, 2013 and December 31, 2012 is comprised of the following items:
		September 30, 2013				December 31, 2012
	Available for sale investments:
	Unrealized gains	$	49,669			$	104,869
	Unrealized losses	(72,057		)		(12,623		)
		(22,388		)		92,246
	Hedging instruments:
	Unrealized gains	3,779				—
	Unrealized losses	(15,754		)		(39,735		)
		(11,975		)		(39,735		)
	Accumulated other comprehensive income	$	(34,363	)		$	52,511

Shareholders_Equity_Schedule_o

Shareholders' Equity Schedule of Additional Paid-In Capital (Tables)	9 Months Ended
	Sep. 30, 2013
Additional Paid in Capital [Abstract]	'
Schedule of Additional Paid in Capital [Table Text Block]	'
	Additional Paid-In Capital
	The following table presents a rollforward of the Company's changes in additional paid-in capital since December 31, 2012:
		2013
	Balance as of January 1, 2013	$	759,214
	Common stock issuances:
	DRIP issuances	5,401
	ATM issuances	1,954
	Incentive plans	147
	Adjustments related to tax withholding for share-based compensation	(545		)
	Common stock repurchases	(5,956		)
	Amortization of restricted stock, net of additional grants	1,736
	Capitalized expenses	(89		)
	Balance as of September 30, 2013	$	761,862

Net_Income_Per_Common_Share_De

Net Income Per Common Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Net Income	($4,627)	$19,167	$46,510	$54,489
Preferred Stock Dividends	-2,294	-814	-5,608	-814
Net income to common shareholders	-6,921	18,353	40,902	53,675
Effect of dilutive stock options, income	'	0	0	0
Diluted net income	($6,921)	$18,353	$40,902	$53,675
Weighted Average Common Shares	54,903,637	54,367,349	54,727,950	52,751,763
Effect of dilutive stock options, number of shares	0	866	0	0
Diluted, Weighted Average Number Common Shares	54,903,637	54,368,215	54,727,950	52,751,763
Basic Net Income Per Common Share	($0.13)	$0.34	$0.75	$1.02
Diluted Net Income Per Common Share	($0.13)	$0.34	$0.75	$1.02
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	'	15,000	'	'

Mortgage_Backed_Securities_Mor2

Mortgage Backed Securities Mortgage backed securities designated as AFS (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	$3,380,838	$3,181,586
Investments, Unamortized Premium (Discount), Net	754,316	800,080
Available-for-sale Securities, Amortized Cost Basis	4,135,154	3,981,666
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	-22,388	92,246
Mortgage-backed Securities Available-for-sale, Fair Value	4,112,766	4,073,912
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	2,984,524	2,706,428
Investments, Unamortized Premium (Discount), Net	648,708	709,246
Available-for-sale Securities, Amortized Cost Basis	3,633,232	3,415,674
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	-35,352	46,916
Mortgage-backed Securities Available-for-sale, Fair Value	3,597,880	3,462,590
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Residential Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	2,723,084	2,425,826
Investments, Unamortized Premium (Discount), Net	162,370	137,168
Available-for-sale Securities, Amortized Cost Basis	2,885,454	2,562,994
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	-56,407	8,343
Mortgage-backed Securities Available-for-sale, Fair Value	2,829,047	2,571,337
Investments, Weighted Average Coupon Rate	3.26%	3.67%
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Commercial Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	261,440	280,602
Investments, Unamortized Premium (Discount), Net	19,844	21,907
Available-for-sale Securities, Amortized Cost Basis	281,284	302,509
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	11,941	21,564
Mortgage-backed Securities Available-for-sale, Fair Value	293,225	324,073
Investments, Weighted Average Coupon Rate	4.82%	5.19%
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Commercial Mortgage Backed Securities, Interest Only [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	0	0
Notional balance for interest only securities	9,682,065	10,059,495
Investments, Unamortized Premium (Discount), Net	466,494	550,171
Available-for-sale Securities, Amortized Cost Basis	466,494	550,171
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	9,114	17,009
Mortgage-backed Securities Available-for-sale, Fair Value	475,608	567,180
Investments, Weighted Average Coupon Rate	0.89%	0.95%
Mortgage-backed Securities, Issued by Private Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	396,314	475,158
Investments, Unamortized Premium (Discount), Net	105,608	90,834
Available-for-sale Securities, Amortized Cost Basis	501,922	565,992
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	12,964	45,330
Mortgage-backed Securities Available-for-sale, Fair Value	514,886	611,322
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Residential Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	14,972	11,411
Investments, Unamortized Premium (Discount), Net	-351	-781
Available-for-sale Securities, Amortized Cost Basis	14,621	10,630
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	-33	408
Mortgage-backed Securities Available-for-sale, Fair Value	14,588	11,038
Investments, Weighted Average Coupon Rate	4.58%	4.28%
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Commercial Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	381,342	463,747
Investments, Unamortized Premium (Discount), Net	-17,213	-17,313
Available-for-sale Securities, Amortized Cost Basis	364,129	446,434
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	10,620	39,908
Mortgage-backed Securities Available-for-sale, Fair Value	374,749	486,342
Investments, Weighted Average Coupon Rate	5.52%	5.31%
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Commercial Mortgage Backed Securities, Interest Only [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Investment Owned, Balance, Principal Amount	0	0
Notional balance for interest only securities	2,857,343	2,393,614
Investments, Unamortized Premium (Discount), Net	123,172	108,928
Available-for-sale Securities, Amortized Cost Basis	123,172	108,928
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	2,377	5,014
Mortgage-backed Securities Available-for-sale, Fair Value	125,549	113,942
Investments, Weighted Average Coupon Rate	0.87%	0.86%
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,129,694	1,026,277
Available-for-sale Securities, Continuous Loss Position Less Than 12 Months, Aggregate Losses	-48,337	-6,552
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	164	83
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	558,070	271,719
Available-for-sale Securities, Continuous Unrealized Loss Position for 12 Months or Longer, Aggregate Losses	-17,718	-5,797
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	67	34
Mortgage-backed Securities, Issued by Private Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	126,846	13,877
Available-for-sale Securities, Continuous Loss Position Less Than 12 Months, Aggregate Losses	-5,902	-76
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	23	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,820	2,701
Available-for-sale Securities, Continuous Unrealized Loss Position for 12 Months or Longer, Aggregate Losses	($100)	($198)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	6	8

Mortgage_Backed_Securities_Mor3

Mortgage Backed Securities Mortgage backed securities designated as Trading (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'	'	'
Trading Securities, Debt	$28,978	'	$28,978	'	$30,069
Trading Securities, Amortized cost	27,078	'	27,078	'	27,535
Unrealized Gain on Securities	96	283	'	716	'
Unrealized Loss on Securities	'	'	($634)	'	'

Repurchase_Agreements_Details

Repurchase Agreements (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	$3,674,850	$3,564,128
Repurchage agreement, Weighted Average Interest Rate	0.59%	0.70%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	4,008,997	3,935,504
Deferred Costs	-347	-659
Weighted Average Maturity of Agreements	'91 days	'57 days
Bonds [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	21,403	28,113
Repurchage agreement, Weighted Average Interest Rate	1.60%	1.64%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	24,853	31,483
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	2,634,120	2,365,982
Repurchage agreement, Weighted Average Interest Rate	0.41%	0.48%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	2,721,562	2,458,200
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	10,932	7,808
Repurchage agreement, Weighted Average Interest Rate	1.80%	1.84%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	13,616	9,634
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	234,633	248,771
Repurchage agreement, Weighted Average Interest Rate	0.39%	0.47%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	294,556	291,445
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	298,548	382,352
Repurchage agreement, Weighted Average Interest Rate	1.29%	1.34%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	364,977	465,306
Commercial Mortgage Backed Securities, Interest Only [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	377,977	443,540
Repurchage agreement, Weighted Average Interest Rate	1.17%	1.22%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	463,894	565,494
Commercial Mortgage Backed Securities, Interest Only [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	97,584	88,221
Repurchage agreement, Weighted Average Interest Rate	1.68%	1.46%
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	$125,539	$113,942

Repurchase_Agreements_Repurcha1

Repurchase Agreements Repurchase Agreements By Maturity Period (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	$3,674,850	$3,564,128
Deferred Costs	-347	-659
Maturity up to 30 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	486,150	622,957
Maturity 31 to 60 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	677,725	1,263,105
Matuity 61 to 90 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	333,007	298,660
Maturity 91 to 120 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	1,021,594	'
Maturity over 90 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	'	1,092,681
Maturity 121 to 150 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	583,888	0
Maturity greater than 150 days [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	572,833	287,384
Repurchase Agreements [Member]	'	'
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]	'	'
Repurchase agreement, balance	$3,675,197	$3,564,787

Repurchase_Agreements_Counterp

Repurchase Agreements Counterparty Information (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified	Agreements
Counterparty Information [Line Items]	'
Concentration Risk, Percentage	17.00%
Amount outstanding with counterparty	$401,404
Weighted average interest rate, amount outstanding with counterparty	1.17%
Line of Credit Facility, Amount Outstanding	$187,508
Line of Credit Facility, Interest Rate at Period End	1.44%
Number of Counterparties with Borrowings Outstanding	21
Available Repurchase Agreement Counterparties	31

Derivatives_Details

Derivatives (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Derivative [Line Items]	'	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$12,908	'	$12,908	'	'
Description of Derivative Activity Volume	'	'	'Information related to the volume of activity for our interest rate derivative instruments subsequent to December 31, 2012 is as follows:(amounts in thousands)Interest Rate Swaps Eurodollar FuturesNotional amount as of December 31, 2012:$1,462,000 $—Additions:380,000 22,100,000Settlements, terminations, or expirations:(150,000) (1,850,000)Notional amount as of September 30, 2013:(1)$1,692,000 $20,250,000(1)The Eurodollar futures notional amount as of September 30, 2013 represents the total notional of the 3-month contracts with expiration dates from 2013 to 2020. The maximum notional outstanding for any 3-month period does not exceed $1,275,000.	'	'
Gain on derivative instruments, net	-24,019	-333	-12,683	-907	'
Derivative Liability, Notional Amount	21,517,000	'	21,517,000	'	1,462,000
Derivative Liabilities	-20,837	'	-20,837	'	-42,537
Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Notional Amount of Derivative Instruments Added	'	'	380,000	'	'
Notional Amount of Derivative Instruments Terminated	'	'	-150,000	'	'
Eurodollar Future [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Notional Amount of Derivative Instruments Added	'	'	22,100,000	'	'
Notional Amount of Derivative Instruments Terminated	'	'	-1,850,000	'	'
Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Gain (Loss) on Derivative Instruments Held for Trading Purposes, Net	-6,225	-333	5,111	-907	'
Derivative Liability, Notional Amount	'	'	'	'	1,462,000
Weighted-average Fixed Rate Swapped	1.64%	'	1.64%	'	'
Interest Rate Swap [Member] | Hedging instrument [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value	'	'	'	'	-39,813
Derivative Liability, Notional Amount	'	'	'	'	1,435,000
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	12,908	'	12,908	'	'
Derivative Asset, Notional Amount	425,000	'	425,000	'	'
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	-20,837	'	-20,837	'	-2,724
Derivative Liability, Notional Amount	1,267,000	'	1,267,000	'	27,000
Derivative, Notional Amount	1,692,000	'	1,692,000	'	'
Eurodollar Future [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Gain (Loss) on Derivative Instruments Held for Trading Purposes, Net	-17,794	0	-17,794	0	'
Eurodollar Future [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative Liability, Notional Amount	20,250,000	'	20,250,000	'	'
Derivative, Notional Amount	20,250,000	'	20,250,000	'	'
Forward Contracts [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	150,000	'	150,000	'	'
Weighted-average Fixed Rate Swapped	2.17%	'	2.17%	'	'
0-12 months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	435,000	'	435,000	'	'
Weighted-average Fixed Rate Swapped	1.26%	'	1.26%	'	'
Interest Rate Swap Agreements, Maturities in Next 13-24 Months [Member] [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	130,000	'	130,000	'	'
Weighted-average Fixed Rate Swapped	2.06%	'	2.06%	'	'
Interest Rate Swap Agreements, Maturities in Next 25-36 Months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	260,000	'	260,000	'	'
Weighted-average Fixed Rate Swapped	1.96%	'	1.96%	'	'
Interest Rate Swap Agreements, Maturities in Next 37-48 Months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	212,000	'	212,000	'	'
Weighted-average Fixed Rate Swapped	0.01%	'	0.01%	'	'
Interest Rate Swap Agreements, Maturities in Next 49-60 Months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	15,000	'	15,000	'	'
Weighted-average Fixed Rate Swapped	2.17%	'	2.17%	'	'
Interest Rate Swap Agreements, Maturities in Next 61-72 Months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	385,000	'	385,000	'	'
Weighted-average Fixed Rate Swapped	1.58%	'	1.58%	'	'
Interest Rate Swap Agreements, Maturities in Next 73-84 Months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	25,000	'	25,000	'	'
Weighted-average Fixed Rate Swapped	1.61%	'	1.61%	'	'
Interest Rate Swap Agreements, Maturities in Next 109-127 Months [Member] | Interest Rate Swap [Member]	'	'	'	'	'
Derivative [Line Items]	'	'	'	'	'
Derivative, Notional Amount	$230,000	'	$230,000	'	'
Weighted-average Fixed Rate Swapped	2.27%	'	2.27%	'	'

Derivatives_Derivatives_Hedgin

Derivatives Derivatives, Hedging Instruments, Consolidated Statement of Comprehensive Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]	'
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$7,911

Derivatives_Derivative_Effect_

Derivatives Derivative Effect on Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Derivative [Line Items]	'	'
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	($11,975,000)	($39,735,000)
Dedesignated cash flow hedge amortization	$0	'

Offsetting_Assets_and_Liabilit3

Offsetting Assets and Liabilities Offsetting Assets (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Offsetting Assets [Line Items]	'	'
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$12,908	'
Derivative Asset, Fair Value, Gross Asset	'	0
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	12,908	0
Derivative, Collateral, Obligation to Return Securities	-1,689	0
Derivative, Collateral, Obligation to Return Cash	-11,219	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	$0	$0

Offsetting_Assets_and_Liabilit4

Offsetting Assets and Liabilities Offsettting Liabilities (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Offsetting Liabilities [Line Items]	'	'
Derivative Liability, Fair Value, Gross Liability	$20,837	$42,537
Derivative Liability, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	20,837	42,537
Derivative, Collateral, Right to Reclaim Securities	-20,175	-42,499
Derivative, Collateral, Right to Reclaim Cash	-490	-38
Derivative Liability, Fair Value, Amount Offset Against Collateral	172	0
Securities Sold under Agreements to Repurchase, Gross	3,674,850	3,564,128
Securities Sold under Agreements to Repurchase, Asset	0	0
Repurchase agreements	3,674,850	3,564,128
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	-3,674,850	-3,564,128
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash	0	0
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral	0	0
Derivative Liability, Securities Sold under Agreements to Resell, Securities Loaned, Gross	3,695,687	3,606,665
Derivative Liability, Securities Sold under Agreements to Resell, Securities Loaned, Asset	0	0
Derivative Liability, Securities Sold under Agreements to Resell, Securities Loaned	3,695,687	3,606,665
Derivative Liability, Securities Sold under Agreements to Resell, Securities Loaned, Collateral, Right to Reclaim Securities	-3,695,025	-3,606,627
Derivative Liability, Securities Sold under Agreements to Resell, Securities Loaned, Collateral, Right to Reclaim Cash	-490	-38
Derivative Liability, Securities Sold under Agreements to Resell, Securities Loaned, Amount Offset Against Collateral	$172	$0

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments Fair Value on a Recurring Basis (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, at fair value	$4,141,744	$4,103,981
Derivative assets	12,908	0
Derivative Liabilities	20,837	42,537
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, at fair value	4,141,744	4,103,981
Other Investments, Fair Value Disclosure	'	25
Derivative assets	12,908	'
Total assets carried at fair value	4,154,652	4,104,006
Derivative Liabilities	20,837	42,537
Total liabilities carried at fair value	20,837	42,537
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, at fair value	0	0
Other Investments, Fair Value Disclosure	'	0
Derivative assets	0	'
Total assets carried at fair value	0	0
Derivative Liabilities	0	0
Total liabilities carried at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, at fair value	4,039,331	3,998,761
Other Investments, Fair Value Disclosure	'	0
Derivative assets	12,908	'
Total assets carried at fair value	4,052,239	3,998,761
Derivative Liabilities	20,837	42,537
Total liabilities carried at fair value	20,837	42,537
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, at fair value	102,413	105,220
Other Investments, Fair Value Disclosure	'	25
Derivative assets	0	'
Total assets carried at fair value	102,413	105,245
Derivative Liabilities	0	0
Total liabilities carried at fair value	$0	$0

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments Significant Unobservable Inputs Level 3 (Details) (Fair Value, Inputs, Level 3 [Member])	3 Months Ended
	Sep. 30, 2013
Non-Agency CMBS [Member]	'
Fair Value Inputs, Quantitative Information [Abstract]	'
Fair Value Inputs, Prepayment Rate	20.00%
Fair Value Inputs, Probability of Default	2.50%
Fair Value Inputs, Loss Severity	35.00%
Fair Value Inputs, Discount Rate	6.50%
Non-Agency RMBS [Member]	'
Fair Value Inputs, Quantitative Information [Abstract]	'
Fair Value Inputs, Prepayment Rate	10.00%
Fair Value Inputs, Probability of Default	1.00%
Fair Value Inputs, Loss Severity	19.90%
Fair Value Inputs, Discount Rate	6.90%

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments Level 3 (Details) (Fair Value, Measurements, Recurring [Member], Fair Value, Inputs, Level 3 [Member], USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Balance at the beginning of the period	$105,245
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	26,021
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	-25
Unrealized (loss) gain included in OCI	-4,814
Principal payments	23,986
Amortization	-28
Balance at the end of the period	102,413
Non-Agency CMBS [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Balance at the beginning of the period	100,102
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	26,021
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	0
Unrealized (loss) gain included in OCI	-4,706
Principal payments	21,731
Amortization	-61
Balance at the end of the period	99,625
Non-Agency RMBS [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Balance at the beginning of the period	5,118
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	0
Unrealized (loss) gain included in OCI	-108
Principal payments	2,255
Amortization	33
Balance at the end of the period	2,788
Other Investments [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Balance at the beginning of the period	25
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	-25
Unrealized (loss) gain included in OCI	'
Principal payments	'
Amortization	'
Balance at the end of the period	$0

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments Recorded basis and Fair Value (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, Fair Value Disclosure	$4,112,766	$4,073,912
Derivative assets	12,908	0
Derivative Liabilities, Fair Value Disclosure	20,837	42,537
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, Fair Value Disclosure	4,141,744	4,103,981
Securitized mortgage loans, Fair Value Disclosure	59,797	70,823
Other Investments, Fair Value Disclosure	1,305	858
Derivative assets	12,908	0
Short-term Debt, Fair Value	3,674,850	3,564,128
Debt Instrument, Fair Value Disclosure	21,148	30,504
Derivative Liabilities, Fair Value Disclosure	20,837	42,537
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage-backed securities, Fair Value Disclosure	4,141,744	4,103,981
Securitized mortgage loans, Fair Value Disclosure	50,932	61,916
Other Investments, Fair Value Disclosure	1,305	810
Derivative assets	12,908	0
Short-term Debt, Fair Value	3,675,197	3,564,787
Debt Instrument, Fair Value Disclosure	20,855	30,756
Derivative Liabilities, Fair Value Disclosure	$20,837	$42,537

Shareholders_Equity_Details

Shareholders' Equity (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Shareholders' Equity, Common Stock [Roll Forward]	'	'	'	'	'
Balance at beginning of period	'	'	54,268,915	'	'
Common stock issued under DRIP	'	'	509,831	'	'
Common stock issued or redeemed under Stock and Incentive Plans	'	'	270,158	'	'
Common stock forfeited for tax withholding on share-based compensation	'	'	-52,385	'	'
Stock Repurchased During Period, Shares	'	'	751,456	'	'
Balance at end of period	54,426,049	'	54,426,049	'	'
Dividend reinvestment plan, shares authorized	3,000,000	'	3,000,000	'	'
Dividends declared per common share	$0.27	$0.29	$0.85	$0.86	'
Additional Paid in Capital [Abstract]	'	'	'	'	'
Additional Paid in Capital, Common Stock beginning of period	'	'	$759,214	'	'
Additional Paid In Capital from DRIP issuances of common stock	'	'	5,401	'	'
Adjustments related to tax withholding for share-based compensation	'	'	545	'	'
Stock Repurchased During Period, Value	'	'	-5,956	'	'
Amortization of restricted stock, net of additional grants	'	'	1,736	'	'
Additional Paid in Capital, Capitalized expenses	'	'	-89	'	'
Additional Paid in Capital, Common Stock, end of period	761,862	'	761,862	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'	'	'	'	'
Accumulated other comprehensive income, available-for-sale securities, gross unrealized gains	49,669	'	49,669	'	104,869
Accumulated other comprehensive income, available-for-sale securities, gross unrealized losses	-72,057	'	-72,057	'	-12,623
Accumulated other comprehensive income from available-for-sale securities, net unrealized gain	-22,388	'	-22,388	'	92,246
Accumulated Other Comprehensive Income (Loss), Unrealized Gains from Cash Flow Hedges, Effect Net of Tax	3,779	'	3,779	'	0
Accumulated other comprehensive income from hedging instruments, unrealized losses	-15,754	'	-15,754	'	-39,735
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	-11,975	'	-11,975	'	-39,735
Accumulated other comprehensive income	-34,363	'	-34,363	'	52,511
Stock Repurchase Program, Authorized Amount	'	'	50,000	'	'
Stock Repurchase Program, Remaining Authorized Repurchase Amount	'	'	43,115	'	'
Stock issued during period, remaining shares available, dividend reinvestment plan	2,472,324	'	2,472,324	'	'
At the market progam [Member]	'	'	'	'	'
Shareholders' Equity, Common Stock [Roll Forward]	'	'	'	'	'
Common stock issued under ATM program	'	'	180,986	'	'
Additional Paid in Capital [Abstract]	'	'	'	'	'
Additional Paid in Capital from ATM issuances of common stock	'	'	1,954	'	'
Stock Compensation Plan [Member]	'	'	'	'	'
Additional Paid in Capital [Abstract]	'	'	'	'	'
Additional Paid in Capital from ATM issuances of common stock	'	'	$147	'	'
Series A Preferred Stock [Member]	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'
Preferred Stock, Dividends Per Share, Declared	$0.53	'	'	'	'
Preferred Stock, Dividend Rate, Percentage	8.50%	'	'	'	'
Preferred Stock, Shares Issued	2,300,000	'	2,300,000	'	2,300,000
Preferred Stock, Par Value Per Share	$0.01	'	$0.01	'	$0.01
Series B Preferred Stock [Member]	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'
Preferred Stock, Dividends Per Share, Declared	$0.48	'	'	'	'
Preferred Stock, Dividend Rate, Percentage	7.63%	'	'	'	'
Preferred Stock, Shares Issued	2,250,000	'	2,250,000	'	0
Preferred Stock, Par Value Per Share	$0.01	'	$0.01	'	$0
Common Stock [Member] | At the market progam [Member]	'	'	'	'	'
Shareholders' Equity, Common Stock [Roll Forward]	'	'	'	'	'
ATM program, authorized shares remaining	7,416,520	'	7,416,520	'	'
Stock Appreciation Rights (SARs) [Member]	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'
Share-based compensation arrangement other than option, vested and outstanding, price per share	$7.06	'	$7.06	'	'

Shareholders_Equity_Sharebased

Shareholders' Equity Share-based Compensation (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, except Share data, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Rights (SARs) [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

12 months or less [Member]

Two to three years [Member]

Three to four years [Member]

Four to five years [Member]

Five years or more [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based incentive plan, number of shares authorized for issuance

2,500,000

'

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

Share-based incentive plan, number of shares remaining for issuance

1,550,118

'

1,550,118

'

'

'

'

'

'

'

'

'

'

'

'

Total share-based compensation expense

$612

$490

$1,726

$1,410

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock outstanding at beginning of the period

'

'

'

'

'

'

526,803

454,117

448,283

365,506

'

'

'

'

'

Restricted stock granted during the period

'

'

'

'

'

'

0

0

255,158

220,821

'

'

'

'

'

Restricted stock vested during the period

'

'

'

'

'

'

-2,917

-2,917

-179,555

-135,127

'

'

'

'

'

Restricted stock outstanding at end of the period

'

'

'

'

'

'

523,886

451,200

523,886

451,200

'

'

'

'

'

Stock Issued During Period, Value, Restricted Stock Award, Gross

'

'

'

'

'

'

'

'

2,708

2,073

'

'

'

'

'

Nonvested restricted stock, fair value remaining to be amortized

'

'

'

'

'

'

3,951

'

3,951

'

640

1,643

1,155

447

0

Stock Appreciation Rights [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock appreciation rights outstanding at end of period

'

'

'

'

25,000

'

'

'

'

'

'

'

'

'

'

Stock appreciation rights outstanding at end of period, weighted average exercise price

'

'

'

'

$7.06

'

'

'

'

'

'

'

'

'

'

Stock appreciation rights, fair value of liability remaining

'

'

'

'

$0

$0

'

'

'

'

'

'

'

'

'

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (Basic Capital Management, Inc et al [Member], DCI [Member], USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]	'	'
Loss Contingency, Allegations	'	'alleged breach by DCI of a $160,000 “master” loan commitment
Damages Sought, Alleged Breach of Agreement, Tenant Improvements [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Damages Sought, Value	'	$250
Damages Sought, Mutually Exclusive Model 1 [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Damages Sought, Value	'	2,200
Damages Sought, Mutually Exclusive Model 2 [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Damages Sought, Value	'	25,600
Damages Sought, Reimbursement of Attorneys' Fees [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Damages Sought, Value	'	2,100
Former affiliates [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Damages Awarded, Value	'	25,600
Loss Contingency, Damages Appealed	'	25,600
Loss Contingency, Management's Assessment and Process	'Management believes the Company will not be obligated for any amounts that may ultimately be awarded against DCI.	'
Former affiliates [Member] | Breach of Loan Agreements [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Loan Commitment, Default Amount	'	$160,000

Subsequent_Events_Amendment_to

Subsequent Events Amendment to Credit Facility (Details) (Subsequent Event [Member], USD $)	Sep. 30, 2013
Subsequent Event [Member]	'
Subsequent Event [Line Items]	'
Line of Credit Facility, Maximum Borrowing Capacity	$250,000

Subsequent_Events_Terminated_S

Subsequent Events Terminated Swaps (Details) (Subsequent Event [Member], USD $)	1 Months Ended
	Nov. 08, 2013
Subsequent Event [Member]	'
Subsequent Event [Line Items]	'
Terminated derivative instruments	$902,000