MTGE Investment (MTGE) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2018	May 01, 2018
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Entity Registrant Name	MTGE Investment Corp.
Entity Central Index Key	1,516,973
Entity Filer Category	Large Accelerated Filer
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		45,797,687
Trading Symbol	MTGE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 3,660,403	$ 3,758,181
Non-agency securities, at fair value (including pledged securities of $760,144 and $743,278, respectively)	833,681	872,084
US Government Securities, at Carrying Value (including pledged securities of $24,903 and $0, respectively)	24,924	0
Land	17,201	16,641
Property, Plant and Equipment, Net	259,775	240,352
Buildings and Improvements, Gross	253,649	233,407
Cash and cash equivalents	123,396	123,762
Restricted cash	40,857	46,324
Interest receivable	14,919	14,608
Derivative assets, at fair value	29,726	14,712
Receivable under reverse repurchase agreements	836,901	843,130
Other assets	16,025	23,242
Total assets	5,857,808	5,953,036
Liabilities:
Secured Debt, Repurchase Agreements	3,743,436	3,863,719
Notes and Loans Payable	201,986	186,500
Payable for Agency and Non-Agency Securities Purchased	58,182	4,357
Derivative liabilities, at fair value	0	4,454
Dividend payable	24,016	24,016
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements, at Fair Value	824,688	830,776
Accounts payable and other accrued liabilities	44,904	33,592
Total liabilities	4,897,212	4,947,414
Stockholders' equity:
8.125% Series A Cumulative Redeemable Preferred Stock; 2,200 shares issued and outstanding (aggregate liquidation preference of $55,000)	53,039	53,039
Common stock, $0.01 par value; 300,000 shares authorized, 45,798 shares issued and outstanding	458	458
Additional paid-in capital	1,122,797	1,122,729
Retained earnings	(216,497)	(171,119)
Total stockholders' equity	959,797	1,005,107
Noncontrolling Interest in Joint Ventures	799	515
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	960,596	1,005,622
Total liabilities and stockholders' equity	$ 5,857,808	$ 5,953,036

Consolidated Balance Sheets Con

Consolidated Balance Sheets Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ / shares in Thousands, $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Preferred Stock, Par or Stated Value Per Share	$ 22	$ 22
Preferred Stock, Shares Authorized	50,000	50,000
Preferred Stock, Shares Issued	2,200	2,200
Preferred Stock, Shares Outstanding	2,200	2,200
Common Stock, Value, Issued	$ 458	$ 458
Common Stock, Shares Authorized	300,000	300,000
Common Stock, Shares, Issued	45,798	45,798
Common Stock, Shares, Outstanding	45,798	45,798
Agency Securities [Member]
Security Owned and Pledged as Collateral, Fair Value	$ 3,434,631	$ 3,581,868
Agency Securities [Member] | Repurchase Agreements [Member]
Security Owned and Pledged as Collateral, Fair Value		3,600,000
Non-Agency Securities [Member]
Security Owned and Pledged as Collateral, Fair Value	760,144	743,278
Non-Agency Securities [Member] | Repurchase Agreements [Member]
Security Owned and Pledged as Collateral, Fair Value	800,000	700,000
US Government Debt Securities [Member]
Security Owned and Pledged as Collateral, Fair Value	$ 24,903	$ 0

Consolidated Statement Of Opera

Consolidated Statement Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest income:
Agency securities	$ 27,511	$ 17,901
Non-agency securities	11,994	15,696
Investment Income, Interest	125	160
Interest expense	(17,053)	(10,165)
Net interest income	22,577	23,592
Healthcare:
Healthcare real estate income	7,760	3,315
Healthcare real estate expense	(5,795)	(2,653)
Net healthcare loss	1,965	662
Other gains (losses):
Realized gain on agency securities, net	(1,940)	(212)
Realized gain on non-agency securities, net	4,154	12,714
Realized loss on periodic settlements of interest rate swaps, net	358	(2,660)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	2,736	2,167
Unrealized gain on agency securities, net	(76,170)	(115)
Unrealized gain on non-agency securities, net	(3,337)	13,014
Unrealized Gain (Loss) on Derivatives	33,457	(2,839)
Other Operating Income	50	2,558
Other Noninterest Expense	250	4,985
Total other gains, net	(40,942)	19,642
Expenses:
Asset Management Costs	3,389	3,376
General and administrative expenses	1,578	1,719
Total expenses	4,967	5,095
Net income	(21,362)	38,799
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(21,367)	38,801
Preferred Stock Dividends, Income Statement Impact	(1,117)	(1,117)
Net Income (Loss) Attributable to Noncontrolling Interest	5	(2)
Net Income (Loss) Available to Common Stockholders, Basic	$ (22,479)	$ 37,682
Earnings Per Share, Basic and Diluted	$ (0.49)	$ 0.82
Weighted Average Number of Shares Outstanding, Basic	45,810	45,798
Weighted Average Number of Shares Outstanding, Diluted	45,822	45,806
Common Stock, Dividends, Per Share, Declared	$ 0.50	$ 0.45

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Noncontrolling Interest [Member]
Noncontrolling Interest in Joint Ventures						$ 315
Beginning Balance, Date Operations Commenced at Dec. 31, 2016	$ 933,045	$ 53,039	$ 458	$ 1,122,493	$ (243,260)
Preferred Stock, Shares Outstanding at Dec. 31, 2016		2,200
Balance, Common Stock, shares at Dec. 31, 2016			45,798
Net income	38,799
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	38,801
Proceeds from Noncontrolling Interests	0
Net Income (Loss) Attributable to Noncontrolling Interest	2					2
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	$ (11)					(11)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures
Stock-based compensation	$ 34			34
Dividends, Preferred Stock, Cash	(1,117)				1,117
Common dividends declared	20,609				20,609
Balance at Mar. 31, 2017		$ 53,039	$ 458	1,122,527	(226,187)
Balance, Common Stock, shares at Mar. 31, 2017			45,798
Preferred Stock, Shares Outstanding at Mar. 31, 2017		2,200
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	950,143
Noncontrolling Interest in Joint Ventures						306
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,005,622
Noncontrolling Interest in Joint Ventures	515					515
Beginning Balance, Date Operations Commenced at Dec. 31, 2017	$ 1,005,107	$ 53,039	$ 458	1,122,729	(171,119)
Preferred Stock, Shares Outstanding at Dec. 31, 2017	2,200	2,200
Balance, Common Stock, shares at Dec. 31, 2017	45,798		45,798
Net income	$ (21,362)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(21,367)
Proceeds from Noncontrolling Interests	293
Net Income (Loss) Attributable to Noncontrolling Interest	(5)					(5)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	$ (4)					(4)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures			$ 0
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	0
Stock-based compensation	$ 68			68
Dividends, Preferred Stock, Cash	(1,117)				1,117
Common dividends declared	(22,899)				22,899
Balance at Mar. 31, 2018	$ 959,797	$ 53,039	$ 458	$ 1,122,797	$ (216,497)
Balance, Common Stock, shares at Mar. 31, 2018	45,798		45,798
Preferred Stock, Shares Outstanding at Mar. 31, 2018	2,200	2,200
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 960,596
Noncontrolling Interest in Joint Ventures	$ 799					$ 799

Consolidated Statement Of Cash

Consolidated Statement Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM (USED IN) OPERATING ACTIVITIES:
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (21,367)	$ 38,801
Adjustments to reconcile net income to net cash used in operating activities:
Investment Income, Amortization of Premium	4,486	5,481
Accretion (Amortization) of Discounts and Premiums, Investments	(3,768)	(6,783)
Depreciation	2,059	771
Amortization of Mortgage Servicing Rights (MSRs)	0	1,089
Unrealized loss (gain) on securities and derivatives, net	46,050	(10,060)
Gain (Loss) on Sale of Investments	1,940	212
Realized gain on non-agency securities, net	(4,154)	(12,714)
Realized loss (gain) on derivatives and securities, net	(3,094)	592
Stock-based compensation	68	34
Increase in interest receivable	(311)	(826)
Increase in other assets	4,024	4,799
Increase in accounts payable and other accrued liabilities	(38)	5,511
Net cash from (used in) operating activities	25,895	26,907
CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES:
Purchases of agency securities	(284,077)	(485,296)
Purchases of non-agency securities	(65,690)	(77,819)
Payments to Acquire Real Estate	(21,984)	(26,634)
Proceeds from sale of agency securities	220,435	208,457
Proceeds from sale of non-agency securities	89,902	260,473
Proceeds from Sale of Mortgage Servicing Rights (MSR)	3,193	43,823
Principal collections on agency securities	107,745	85,136
Proceeds From Principal Collection Of Non Agency Mortgag eBacked Securities	18,776	43,258
Proceeds from (Payments for) Securities Purchased under Agreements to Resell	6,229	(847,588)
Purchase Of US Treasury Securities	(141,912)	(332,959)
Proceeds from sale of U.S. Treasury securities	153,449	1,193,721
Payments for Derivative Instrument, Investing Activities	0	(3,841)
Payments for (Proceeds from) Other Investing Activities	10,788	(12,098)
Net cash flows from (used in) investing activities	96,854	48,633
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Payments of Dividends	(24,016)	(19,436)
Proceeds from Noncontrolling Interests	293	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(4)	(11)
Proceeds from repurchase agreements	5,503,995	5,987,161
Repayments of Short-term Debt	(5,624,278)	(6,035,054)
Proceeds from Issuance of Secured Debt	15,938	19,774
Repayments of Secured Debt	(510)	(93)
Net cash flow from (used in) financing activities	(128,582)	(47,659)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(5,833)	27,881
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 164,253	$ 164,526

Unaudited Interim Consolidated

Unaudited Interim Consolidated Financial Statements (Notes)	3 Months Ended
	Mar. 31, 2018
Unaudited Interim Financial Statements [Abstract]
Unaudited Interim Consolidated Financial Statements [Text Block]	Unaudited Interim Consolidated Financial Statements The unaudited interim consolidated financial statements of MTGE Investment Corp. (referred to throughout this report as the “Company”, “we”, “us” and “our”) are prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Our unaudited interim consolidated financial statements include the accounts of all of our subsidiaries. Significant intercompany accounts and transactions have been eliminated. In the opinion of management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair presentation of financial statements for the interim period have been included. The current period’s results of operations are not necessarily indicative of results that ultimately may be achieved for the year.

Organization (Notes)

Organization (Notes)	3 Months Ended
	Mar. 31, 2018
Organization [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Organization We were incorporated in Maryland and commenced operations in 2011 following the completion of our initial public offering (“IPO”). We are externally managed by MTGE Management, LLC (our “Manager”), an affiliate of AGNC Investment Corp. (“AGNC”). Our common stock is traded on the Nasdaq Global Select Market under the symbol “MTGE.” We invest in, finance and manage a leveraged portfolio of real estate-related investments, which include agency residential mortgage-backed securities (“agency RMBS”), non-agency securities, other mortgage-related investments and other real estate investments. Agency RMBS include residential mortgage pass-through certificates and collateralized mortgage obligations (“CMOs”) structured from residential mortgage pass-through certificates for which the principal and interest payments are guaranteed by a government-sponsored enterprise (“GSE”), such as Federal National Mortgage Association (“Fannie Mae”) and Federal Home Loan Mortgage Corporation (“Freddie Mac”), or by a U.S. Government agency, such as Government National Mortgage Association (“Ginnie Mae”). Non-agency securities include securities backed by residential mortgages that are not guaranteed by a GSE or U.S. Government agency and credit risk transfer securities (“CRT”). Other mortgage-related investments may include mortgage servicing rights (“MSR”), commercial mortgage-backed securities (“CMBS”), prime and non-prime residential mortgage loans, commercial mortgage loans and mortgage-related derivatives. Other real estate investments include equity investments in healthcare and senior living facilities that are leased to or operated by third parties who conduct all business operations of the facilities. Our objective is to provide attractive risk-adjusted returns to our stockholders through a combination of dividends and net asset value appreciation. In pursuing this objective, we rely on our Manager’s expertise to construct and manage a diversified investment portfolio by selecting assets that, when properly financed and hedged, are expected to produce attractive risk-adjusted returns across a variety of market conditions and economic cycles. We have elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). As such, we are required to distribute annually at least 90% of our taxable income. As a REIT, we will generally not be subject to U.S. Federal or state corporate taxes on our taxable income to the extent that we distribute all of our annual taxable income to our stockholders. It is our intention to distribute 100% of our taxable income, after application of available tax attributes, within the time limits prescribed by the Internal Revenue Code, which may extend into the subsequent taxable year.

Agency Securities

Agency Securities	3 Months Ended
	Mar. 31, 2018
Agency Securities [Abstract]
Agency Securities	Agency Securities The following tables summarize our investments in agency RMBS as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Fannie Mae Freddie Mac Total Agency RMBS: Par value $ 2,393,236 $ 1,196,372 $ 3,589,608 Unamortized premium 118,223 63,641 181,864 Amortized cost 2,511,459 1,260,013 3,771,472 Gross unrealized gains 688 281 969 Gross unrealized losses (75,332 ) (36,706 ) (112,038 ) Agency RMBS, at fair value $ 2,436,815 $ 1,223,588 $ 3,660,403 Weighted average coupon as of March 31, 2018 3.61 % 3.73 % 3.65 % Weighted average yield as of March 31, 2018 2.82 % 2.96 % 2.87 % Weighted average yield for the three months ended March 31, 2018 2.94 % 3.12 % 3.00 % March 31, 2018 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 3,698,545 $ 718 $ (111,935 ) $ 3,587,328 Adjustable rate 72,927 251 (103 ) 73,075 Total Agency RMBS $ 3,771,472 $ 969 $ (112,038 ) $ 3,660,403 December 31, 2017 Fannie Mae Freddie Mac Total Agency RMBS: Par value $ 2,485,055 $ 1,117,551 $ 3,602,606 Unamortized premium 127,008 63,466 190,474 Amortized cost 2,612,063 1,181,017 3,793,080 Gross unrealized gains 3,876 1,149 5,025 Gross unrealized losses (28,364 ) (11,560 ) (39,924 ) Agency RMBS, at fair value $ 2,587,575 $ 1,170,606 $ 3,758,181 Weighted average coupon as of December 31, 2017 3.63 % 3.75 % 3.67 % Weighted average yield as of December 31, 2017 2.78 % 2.89 % 2.82 % Weighted average yield for the year ended December 31, 2017 2.67 % 2.69 % 2.68 % December 31, 2017 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 3,717,285 $ 3,707 $ (39,924 ) $ 3,681,068 Adjustable rate 75,795 1,318 — 77,113 Total Agency RMBS $ 3,793,080 $ 5,025 $ (39,924 ) $ 3,758,181 Actual maturities of agency RMBS are generally shorter than the stated contractual maturities. Actual maturities are affected by the contractual lives of the underlying mortgages, periodic principal payments and principal prepayments. The following table summarizes our agency RMBS as of March 31, 2018 and December 31, 2017 according to their estimated weighted average life classification (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Estimated Weighted Fair Value Amortized Cost Yield Coupon Fair Value Amortized Cost Yield Coupon Less than or equal to three years $ 42,371 $ 43,132 2.10 % 3.93 % $ 40,404 $ 40,815 2.06 % 3.92 % Greater than three years and less than or equal to five years 489,624 498,048 2.39 % 3.15 % 534,299 535,608 2.38 % 3.19 % Greater than five years and less than or equal to 10 years 2,872,403 2,967,793 2.94 % 3.74 % 3,149,565 3,182,468 2.90 % 3.75 % Greater than 10 years 256,005 262,499 3.15 % 3.55 % 33,913 34,189 2.98 % 3.50 % Total $ 3,660,403 $ 3,771,472 2.87 % 3.65 % $ 3,758,181 $ 3,793,080 2.82 % 3.67 % As of March 31, 2018 and December 31, 2017 , the estimated weighted average life of our agency security portfolio was 8.0 years and 7.5 years , respectively, which incorporates anticipated future prepayment assumptions. As of March 31, 2018 and December 31, 2017 , our weighted average expected constant prepayment rate (“CPR”) over the remaining life of our aggregate agency investment portfolio was 7.6% and 8.4% , respectively. Realized Gains and Losses The following table summarizes our net realized gains and losses from the sale of agency RMBS during three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Proceeds from agency securities sold $ 220,435 $ 208,457 Less agency securities sold, at cost (222,375 ) (208,669 ) Realized loss on agency securities, net $ (1,940 ) $ (212 ) Gross realized gains on sale of agency securities $ 14 $ 1,270 Gross realized losses on sale of agency securities (1,954 ) (1,482 ) Realized loss on agency securities, net $ (1,940 ) $ (212 ) Pledged Assets The following tables summarize our agency RMBS pledged as collateral under financing and derivative agreements by type as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Fannie Mae Freddie Mac Total Fair Value of Agency Securities Pledged Under: Financing agreements $ 2,294,011 $ 1,140,080 $ 3,434,091 Derivative agreements 80 460 540 Total fair value 2,294,091 1,140,540 3,434,631 Accrued interest on pledged agency RMBS 6,800 3,476 10,276 Total Fair Value of Agency RMBS Pledged and Accrued Interest $ 2,300,891 $ 1,144,016 $ 3,444,907 December 31, 2017 Fannie Mae Freddie Mac Total Fair Value of Agency Securities Pledged Under: Financing agreements $ 2,443,591 $ 1,137,587 $ 3,581,178 Derivative agreements 84 606 690 Total fair value 2,443,675 1,138,193 3,581,868 Accrued interest on pledged agency RMBS 7,132 3,399 10,531 Total Fair Value of Agency RMBS Pledged and Accrued Interest $ 2,450,807 $ 1,141,592 $ 3,592,399 The following table summarizes our agency RMBS pledged as collateral under financings agreements, by remaining maturity, including securities pledged related to sold but not yet settled securities, as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Remaining Maturity Fair Value Amortized Cost Accrued Interest Fair Value Amortized Cost Accrued Interest 30 days or less $ 1,102,225 $ 1,136,865 $ 3,262 $ 940,788 $ 949,282 $ 2,765 31 - 59 days 985,955 1,015,732 2,974 1,298,331 1,311,882 3,818 60 - 90 days 359,108 370,094 1,096 261,823 262,908 785 Greater than 90 days 986,803 1,019,398 2,944 1,080,236 1,091,195 3,161 Total $ 3,434,091 $ 3,542,089 $ 10,276 $ 3,581,178 $ 3,615,267 $ 10,529 As of March 31, 2018 and December 31, 2017 , none of our repurchase agreement borrowings backed by agency RMBS had original overnight maturities.

Summary of Significant Accounti

Summary of Significant Accounting Policies (Notes)	3 Months Ended
	Mar. 31, 2018
Summary of Significant Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Fair Value of Financial Assets We have elected the option to account for all of our financial assets, including all mortgage-related investments, at estimated fair value, with changes in fair value reflected in income during the period in which they occur. In management's view, this election more appropriately reflects the results of our operations for a particular reporting period, as financial asset fair value changes are presented in a manner consistent with the presentation and timing of the fair value changes of hedging instruments. See Note 10 - Fair Value Measurements. Interest Income Interest income is accrued based on the outstanding principal amount of the securities and their contractual terms. Premiums or discounts associated with the purchase of agency RMBS and non-agency securities of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method. We estimate long-term prepayment speeds using a third-party service and market data. Actual and anticipated prepayment experience is reviewed at least quarterly and effective yields are recalculated when differences arise between the previously estimated future prepayments and the amounts received plus currently anticipated future prepayments. If the actual and anticipated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield through the reporting date. At the time we purchase non-agency securities that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments, based on inputs and analysis received from external sources, internal models, and our judgment about interest rates, prepayment rates, the timing and amount of credit losses, and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment as adjusted for credit impairment, if any. Real Property Owned Tangible assets primarily consist of land, buildings and furniture, fixtures and equipment. Depreciable tangible assets are depreciated on a straight-line basis over their estimated useful lives, which can range from 3 years for furniture, fixtures and equipment to 40 years for buildings. On January 1, 2017 the Company adopted Accounting Standards Update (“ASU”) No. 2017-01, Clarifying the Definition of a Business (“ASU 2017-01”) which provides a framework to determine whether a transaction involves an asset, or a group of assets, or a business. ASU 2017-01 states that when substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the transaction should not be considered a business combination. The ASU also clarifies the requirements for a set of activities to be considered a business and narrows the definition of outputs that would lead to business combination accounting treatment. As a result of these changes, the Company expects that a majority of its future real estate acquisitions and dispositions will be deemed asset transactions rather than business combinations. For asset acquisitions subsequent to January 1, 2017, the Company records identifiable assets acquired, liabilities assumed and any associated noncontrolling interests at cost on a relative fair value basis, with no goodwill recognized and third-party transaction costs capitalized. The net book value of long-lived assets is reviewed quarterly on a property by property basis to determine if facts and circumstances suggest that the assets may be impaired or that depreciable lives may need to be changed. We consider external factors relating to each asset and the existence of a master lease that may link the cash flows of an individual asset to a larger portfolio of assets leased to the same tenant. If these factors and the projected undiscounted cash flows of the asset over the remaining depreciation period indicate that the asset will not be recoverable, the carrying value is reduced to the estimated fair market value. In addition, we are exposed to the risks inherent in investments in real estate and, in particular, the senior housing and healthcare industries. A downturn in these industries or in the real estate markets in which our properties are located could adversely affect the value of our properties and our ability to sell properties for a price or terms acceptable to us. Intangible Assets Intangible assets can include goodwill and identifiable intangible assets such as above or below market component of in-place leases and the value associated with the presence of in-place tenants or residents. Goodwill is calculated as the excess of consideration transferred over the estimated fair value of net assets recognized and represents the estimated future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Goodwill and intangible assets are included in other assets on the consolidated balance sheets and tested for impairment annually or more frequently if events and circumstances indicate that the asset might be impaired. Healthcare Real Estate Income Healthcare real estate income consists primarily of lease and rental income. For operating leases with minimum scheduled rent increases, the Company recognizes income on a straight line basis over the lease term when collectability is reasonably assured. Recognizing lease income on a straight line basis results in a difference in the timing of revenue amounts from what is contractually due. If the Company determines that collectability of straight line lease income is not reasonably assured, future revenue recognition is limited to amounts contractually owed and paid, and, when appropriate, an allowance for estimated losses is established. Resident rental income is recorded when services are rendered and includes resident room and care charges, community fees and other resident charges. Residency agreements are generally for a term of 30 days to one year, with resident fees billed monthly. Revenue for certain care-related services is recognized as the services are provided. Noncontrolling Interests Arrangements with noncontrolling interest holders are reported as a component of equity separate from the Company’s stockholders' equity, recorded at the initial carrying amount, and increased or decreased for the noncontrolling interest’s share of net income or loss. Net income attributable to a noncontrolling interest is included in net income on the consolidated statements of operations. Deferred Loan Expenses We amortize deferred financing costs, which are reported within notes payable, net of deferred financing costs on our consolidated balance sheets, as a component of interest expense of the debt over the terms of the related borrowings using a method that approximates a level yield. Repurchase Agreements We finance the acquisition of agency RMBS and non-agency securities through repurchase transactions under master repurchase agreements. We account for repurchase transactions as collateralized financing transactions which are carried at their contractual amounts, including accrued interest, as specified in the respective transaction agreements. The contractual amounts approximate fair value due to their short-term maturities or floating rate coupons. Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivatives below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the consolidated balance sheets based on the value of the underlying borrowed securities as of the reporting date. The fair value of our reverse repurchase agreements is assumed to equal cost as they generally mature daily or have interest rates that are reset daily. Derivatives We utilize a risk management strategy, under which we may use a variety of derivative instruments to mitigate our exposure to market risks, including interest rate risk, prepayment risk, extension risk and credit risk. The objective of our risk management strategy is to reduce fluctuations in net asset value over a range of market conditions. The principal instruments that we currently use are interest rate swaps and options to enter into interest rate swaps (“interest rate swaptions”). We also utilize forward contracts for the purchase or sale of agency RMBS, or to-be-announced forward (“TBA”) contracts, and short sales of U.S. Treasury securities and U.S. Treasury futures contracts. We may also purchase or sell options on TBA securities and utilize other types of derivative instruments. We also enter into TBA contracts as a means of investing in and financing agency RMBS (thereby increasing our “at risk” leverage) or as a means of disposing of or reducing our exposure to agency RMBS (thereby reducing our “at risk” leverage). Pursuant to TBA contracts, we agree to purchase or sell, for future delivery, agency RMBS with certain principal and interest terms and certain types of collateral, but the particular agency RMBS to be delivered are not identified until shortly before the TBA settlement date. We may also choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting short or long position (referred to as a “pair off”), net settling the paired off positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date. This transaction is commonly referred to as a “dollar roll.” The agency RMBS purchased or sold for a forward settlement date are typically priced at a discount to agency RMBS for settlement in the current month. This difference (or discount) is referred to as the “price drop.” The price drop is the economic equivalent of net interest carry income on the underlying agency RMBS over the roll period (interest income less implied financing cost) and is commonly referred to as “dollar roll income (loss).” Consequently, forward purchases of agency RMBS and dollar roll transactions represent a form of off-balance sheet financing. We present all derivative instruments as either assets or liabilities at fair value on our consolidated balance sheets and report all changes in fair value in earnings in our consolidated statements of operations in unrealized gain (loss) on other derivatives and securities, net during the period in which they occur. Derivatives in a gain position are reported as derivative assets at fair value and derivatives in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with each counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized in the event counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral based on daily market value changes. We also attempt to minimize our risk of loss by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with short-term borrowings made under our repurchase agreement and other financing facilities. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one, three or six-month LIBOR (“payer swaps”) with terms up to 15 years. The floating rate we receive under our swap agreements has the effect of offsetting the repricing characteristics of our repurchase agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over-the-counter (“OTC”) market. Swap agreements entered into subsequent to May 2013 are centrally cleared through the Chicago Mercantile Exchange (“CME”), a registered commodities exchange. We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references observable market inputs, including LIBOR, swap rates and the forward yield curve, to produce the daily settlement price. Our centrally cleared swaps require that we post an “initial margin” to our counterparties for an amount determined by the CME, which is generally intended to be set at a level sufficient to protect the CME from the maximum estimated single-day price movement in that market participant’s contracts. We also exchange cash “variation margin” with our counterparties on our centrally cleared swaps based upon daily changes in the fair value as measured by the CME. Beginning in the first quarter of 2017, as a result of a CME amendment to its rule book governing central clearing activities, the daily exchange of variation margin associated with a CME centrally cleared derivative instrument is legally characterized as the daily settlement of the derivative instrument itself, as opposed to a pledge of collateral. Accordingly, beginning in 2017, we account for the daily receipt or payment of variation margin associated with our centrally cleared interest rate swaps as a direct reduction to the carrying value of the interest rate swap derivative asset or liability, respectively. Beginning in 2017, the carrying amount of centrally cleared interest rate swaps reflected in our consolidated balance sheets is equal to the unsettled fair value of such instruments. We estimate the fair value of our “non-centrally cleared” interest rate swaps based on valuations obtained from third-party pricing services and the swap counterparty (collectively, “third-party valuations”). The third-party valuations are model-driven using observable inputs, including LIBOR, swap rates and the forward yield curve. We also consider the creditworthiness of both us and our counterparties and the impact of netting and credit enhancement provisions contained in each derivative agreement, such as collateral postings. All of our “non-centrally cleared” interest rate swaps are subject to bilateral collateral arrangements. Consequently, no credit valuation adjustment was made in determining the fair value of such instruments. The payment of periodic settlements of net interest on interest rate swaps is reported in realized loss on periodic settlements of interest rate swaps, net in our consolidated statements of operations. Cash payments received or paid for the early termination of an interest rate swap agreement are recorded as realized loss on other derivatives and securities, net in our consolidated statements of operations. Changes in fair value of our interest rate swap agreements are reported in unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. The interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay or receive interest rates in the future. The premium paid for interest rate swaptions is reported as a derivative asset in our consolidated balance sheets. We estimate the fair value of interest rate swaptions based on the fair value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option. The difference between the premium and the fair value of the swaption is reported in unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid and reported in realized loss on other derivatives and securities, net in our consolidated statements of operations. If we exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the fair value of the underlying interest rate swap and the premium paid and reported in realized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. Interest rate swaption agreements are privately negotiated in the OTC market and are not subject to central clearing. We estimate the fair value of our interest rate swaption agreements based on model-driven valuations obtained from third-party pricing services and the swaption counterparty. These estimates incorporate observable inputs and include the fair value of the future interest rate swaps that we have the option to enter into, as well as the remaining length of time that we have to exercise the options, adjusted for non-performance risk, if any. TBA securities TBA securities are forward contracts for the purchase (“long position”) or sale (“short position”) of agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific agency RMBS delivered into the contract upon the settlement date, published each month by the Securities Industry and Financial Markets Association, are not known at the time of the transaction. We may enter into TBA contracts as a means of hedging against short-term changes in interest rates. We may also enter into TBA dollar roll transactions to finance agency RMBS purchases. We account for all TBA contracts as derivatives since we cannot assert that it is probable at the inception and throughout the term of the contract that it will not settle net and will result in physical delivery of an agency security when it is issued. A TBA dollar roll transaction is a series of derivative transactions. The net settlement of a TBA contract is reported as realized gain (loss) on other derivatives and securities, net and changes in the fair value of our TBA contracts are reported as unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. We estimate the fair value of TBA securities based on similar methods used to value our agency RMBS. U.S. Treasury securities We purchase or sell short U.S. Treasury securities and U.S. Treasury futures contracts to help mitigate the potential impact of changes in interest rates on the performance of our portfolio. Realized gains and losses associated with purchases and short sales of U.S. Treasury securities and U.S. Treasury futures contracts are recognized in realized gain (loss) on other derivatives and securities, net, and unrealized gains and losses are recognized in unrealized gain (loss) on other derivatives and securities, net on our consolidated statements of operations. Adoption of Accounting Standard Updates As of January 1, 2018, we adopted Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606), and ASU 2016-18 , Statement of Cash Flows (Topic 230) - Restricted Cash. Net income was not impacted. The adoption of ASU 2016-18 resulted in the presentation of restricted cash with cash and cash equivalents on the consolidated statements of cash flows when reconciling the total beginning and ending amounts. Our prior period results have been revised to conform to the current presentation.

Non-Agency Securities

Non-Agency Securities	3 Months Ended
	Mar. 31, 2018
Non-agency Securities [Abstract]
Non-Agency Securities	Non-Agency Securities The following tables summarize our non-agency securities as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Fair Value Gross Unrealized Amortized Cost Premium (Discount) Par/ Current Face Weighted Average Category Gains Losses Coupon (1) Yield Prime $ 139,841 $ 9,529 $ (77 ) $ 130,389 $ (13,262 ) $ 143,651 3.86 % 5.89 % CRT 300,338 16,465 (81 ) 283,954 13,258 270,696 5.50 % 5.68 % Alt-A 277,083 50,162 (628 ) 227,549 (109,122 ) 336,671 2.94 % 9.21 % Option-ARM 84,683 12,790 — 71,893 (20,305 ) 92,198 2.11 % 6.79 % Subprime 13,337 873 — 12,464 (664 ) 13,128 5.20 % 5.92 % CMBS 18,399 171 (85 ) 18,313 (187 ) 18,500 5.68 % 6.04 % Total $ 833,681 $ 89,990 $ (871 ) $ 744,562 $ (130,282 ) $ 874,844 3.91 % 6.92 % ———————— (1) Coupon rates are floating, except for $11.4 million , $5.6 million , $12.0 million , $13.3 million and $18.4 million fair value of fixed-rate prime, CRT, Alt-A, subprime and CMBS non-agency securities, respectively, as of March 31, 2018 . December 31, 2017 Fair Value Gross Unrealized Amortized Cost Premium (Discount) Par/ Current Face Weighted Average Category Gains Losses Coupon (1) Yield Prime $ 143,329 $ 9,342 $ (12 ) $ 133,999 $ (13,893 ) $ 147,892 3.77 % 5.66 % CRT 322,819 18,346 — 304,473 16,011 288,462 5.34 % 5.23 % Alt-A 286,953 51,123 (774 ) 236,604 (112,305 ) 348,909 2.69 % 8.93 % Option-ARM 86,886 13,114 — 73,772 (21,044 ) 94,816 1.79 % 6.58 % Subprime 13,374 929 — 12,445 (683 ) 13,128 5.20 % 5.97 % CMBS 18,723 387 — 18,336 (164 ) 18,500 5.68 % 6.03 % Total $ 872,084 $ 93,241 $ (786 ) $ 779,629 $ (132,078 ) $ 911,707 3.73 % 6.59 % ———————— (1) Coupon rates are floating, except for $11.8 million , $0.9 million , $12.2 million , $13.4 million and $18.7 million fair value of fixed-rate prime, CRT, Alt-A, subprime and CMBS non-agency securities, respectively, as of December 31, 2017 . The following table summarizes our non-agency securities at fair value, by their estimated weighted average life classifications as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Estimated Weighted Average Life Fair Value Amortized Cost Coupon Yield Fair Value Amortized Cost Coupon Yield ≤ 5 years $ 285,566 $ 244,884 3.33 % 8.44 % $ 302,797 $ 258,501 3.11 % 8.31 % > 5 to ≤ 7 years 258,753 226,721 4.17 % 7.05 % 398,712 361,649 4.33 % 5.97 % > 7 years 289,362 272,957 4.35 % 5.43 % 170,575 159,479 3.61 % 5.18 % Total $ 833,681 $ 744,562 3.91 % 6.92 % $ 872,084 $ 779,629 3.73 % 6.59 % Our Prime non-agency securities include investments in securitization trusts collateralized by prime mortgage loans, which were originated between 2002 and 2006, a period of generally weaker underwriting standards and elevated housing prices. As a result, there is still material credit risk embedded in these loan origination vintages. As of March 31, 2018 , Prime non-agency securities also include $17.2 million in fair value of securities with underlying mortgage loans that were originated with more stringent underwriting standards beginning in 2010. As of March 31, 2018 , our Prime securities have both fixed and floating rate coupons ranging from 2.5% to 6.5% , with weighted average coupons of underlying collateral ranging from 3.5% to 5.0% . Our CRT reference the performance of loans underlying agency RMBS issued by Fannie Mae or Freddie Mac, which were subject to their underwriting standards. As of March 31, 2018 , our CRT securities had fixed and floating rate coupons ranging from 1.3% to 8.8% , with weighted average coupons of underlying collateral ranging from 3.6% to 4.3% . The loans underlying our CRT securities were originated between 2012 and 2018. Our Alt-A non-agency RMBS are collateralized by Alt-A mortgage loans that were originated from 2002 to 2007. Alt-A, or alternative A-paper, mortgage loans are considered to have more credit risk than prime mortgage loans and less credit risk than sub-prime mortgage loans. Alt-A loans are typically characterized by borrowers with less than full documentation, lower credit scores, higher loan-to-value ratios and a higher percentage of investment properties. As of March 31, 2018 , our Alt-A securities had both fixed and floating rate coupons ranging from 2.0% to 6.5% with weighted average coupons of underlying collateral ranging from 3.6% to 5.8% . Our Option-ARM non-agency RMBS include senior tranches in securitization trusts that are collateralized by residential mortgages that have origination and underwriting characteristics similar to Alt-A mortgage loans, with the added feature of providing underlying mortgage borrowers the option, within certain constraints, to make lower payments than otherwise required by the stated interest rate for a number of years, leading to negative amortization and increased loan balances. This additional feature can increase the credit risk of these securities. As of March 31, 2018 , our Option-ARM securities had coupons ranging from 2.0% to 2.6% and have underlying collateral with weighted average coupons between 3.5% and 4.5% . The loans underlying our Option-ARM securities were originated between 2004 and 2007. Our Subprime non-agency RMBS include investments in securitization trusts collateralized by residential mortgages originated during or before 2005 that were originally considered to be of lower credit quality. As of March 31, 2018 , our Subprime securities had a fair value of $13.3 million with fixed and floating rate coupons ranging from 5.0% to 5.5% and have underlying collateral with weighted-average coupons ranging from 5.5% to 5.7% . Our CMBS are collateralized by a commercial mortgage loan originated in 2016 that is secured by first priority liens on 64 skilled nursing facilities. As of March 31, 2018 , our CMBS securities had a fair market value of $18.4 million with fixed rate coupons ranging from 5.2% to 6.6% and underlying collateral with a weighted average coupon of 4.5% . More than 87% of our non-agency RMBS are rated below investment grade or have not been rated by credit agencies as of March 31, 2018 . Realized Gains and Losses The following table summarizes our net realized gains from the sale of non-agency securities during three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Proceeds from non-agency securities sold $ 89,901 $ 260,473 Increase in receivable for securities sold — 5,748 Less: non-agency securities sold, at cost (85,747 ) (253,507 ) Realized gain on non-agency securities, net $ 4,154 $ 12,714 Gross realized gain on sale of non-agency securities $ 4,155 $ 12,864 Gross realized loss on sale of non-agency securities (1 ) (150 ) Realized gain on non-agency securities, net $ 4,154 $ 12,714 Pledged Assets Non-agency securities with a fair value of $0.8 billion and $0.7 billion were pledged as collateral under financing arrangements as of March 31, 2018 and December 31, 2017 , respectively, none of which had original overnight maturities. The following table summarizes our non-agency securities pledged as collateral under repurchase agreements, by remaining maturity, including securities pledged related to sold but not yet settled securities, as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Remaining Maturity Fair Value Amortized Accrued Interest Fair Value Amortized Accrued Interest 30 days or less $ 686,521 $ 614,635 $ 1,052 $ 585,943 $ 517,750 $ 815 31 - 59 days 60,500 50,754 75 97,537 82,105 145 60 - 90 days 13,123 10,311 17 59,798 58,651 135 Total $ 760,144 $ 675,700 $ 1,144 $ 743,278 $ 658,506 $ 1,095

Investments in Real Property In

Investments in Real Property Investments (Notes)	3 Months Ended
	Mar. 31, 2018
Investment in Real Property [Abstract]
Real Estate Disclosure [Text Block]	Investments in Real Property Investment Activity During March 2018, CHI acquired a senior living facility located in Kansas for total consideration of $21.5 million through an existing joint venture structured in a manner intended to comply with the REIT Income Diversification and Empowerment Act (“RIDEA”). The total purchase price has been allocated to assets and liabilities based upon their respective fair values in accordance with our accounting policies. As a result of these purchase price allocations, $20.0 million was allocated to buildings, $0.9 million to furniture, fixtures and equipment and $0.6 million to land during the first quarter of 2018. The following table summarizes our real estate investments net of accumulated depreciation as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Buildings and improvements $ 253,649 $ 233,407 Furniture, fixtures and equipment 15,719 14,537 Less: accumulated depreciation (9,593 ) (7,592 ) Buildings, furniture, fixtures and equipment, net of accumulated depreciation 259,775 240,352 Land 17,201 16,641 Goodwill 5,840 5,840 Net working capital (1) 16,369 18,994 Total real estate assets $ 299,185 $ 281,827 ———————— (1) Net working capital primarily includes $14.7 million and $16.1 million of cash and cash equivalents and $3.4 million and $2.8 million of rent receivable recorded in other assets on the consolidated balances sheets as of March 31, 2018 and December 31, 2017 , respectively. Notes Payable CHI finances its real estate investments primarily through secured debt. As of March 31, 2018 , CHI had fixed rate debt with a principal amount of $138.3 million , a weighted average maturity of 25.3 years and an interest rate of 3.81% and floating rate debt with a principal amount of $66.4 million , a weighted average maturity of 0.9 years and a weighted average interest rate of 4.63% . As of December 31, 2017 , CHI had floating rate debt with a principal amount of $50.3 million , a weighted average maturity of 0.8 years and a weighted average interest rate of 4.34% and fixed rate debt with a principal amount of $138.8 million , a weighted average maturity of 25.6 years and an interest rate of 3.80% . The following is a summary of our notes payable activity for the three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Beginning balance $ 186,500 $ 66,527 Debt issued and assumed, net of deferred financing costs 15,938 19,581 Amortization of deferred financing costs 58 193 Principal repayments (510 ) (93 ) Ending balance $ 201,986 $ 86,208 Our notes payable of $204.7 million , excluding $2.7 million of deferred financing costs, had a fair value of approximately $198 million as of March 31, 2018 . Our notes payable of $189.0 million , excluding $2.5 million of deferred financing costs, had a fair value of approximately $190 million as of December 31, 2017 . Income from Healthcare Real Estate Investments The following table presents the components of net income from our real property investments during the three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Lease income $ 5,706 $ 2,253 Rental income 2,054 1,062 Healthcare real estate income 7,760 3,315 Interest expense 2,089 1,173 Depreciation 2,001 771 Tenant expenses 1,425 709 Other 280 — Healthcare real estate expense 5,795 2,653 Net healthcare investment income $ 1,964 $ 662 Healthcare lease income is derived from our real property investments subject to triple net lease arrangements, and rental income relates to investments made through RIDEA joint ventures. Under RIDEA, a REIT may lease “qualified healthcare properties” on an arm’s-length basis to a taxable REIT subsidiary (“TRS”) if the property is operated on behalf of such subsidiary by a person who qualifies as an “eligible independent contractor.” Generally, the rent received from the TRS will meet the related party rent exception and will be treated as “rents from real property.” Resident level rents and related operating expenses are subject to federal and state income taxes as the operations of such facilities are included in a TRS. At March 31, 2018 , future minimum lease payments receivable related to our healthcare and senior living facilities are as follows (dollars in thousands): March 31, 2018 2018 $ 15,301 2019 20,764 2020 21,191 2021 21,627 2022 22,073 Thereafter 193,233 Total $ 294,189

Repurchase Agreements

Repurchase Agreements	3 Months Ended
	Mar. 31, 2018
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements	Repurchase Agreements We pledge certain of our securities as collateral under repurchase and other financing arrangements with financial institutions and the terms and conditions are negotiated on a transaction-by-transaction basis. Interest rates on these borrowings are generally based on LIBOR plus or minus a margin and amounts available to be borrowed are dependent upon the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, type of security and liquidity conditions within the banking, mortgage finance and real estate industries. In response to declines in fair value of pledged securities, lenders may require us to post additional collateral or pay down borrowings to re-establish agreed upon collateral requirements, referred to as margin calls. As of March 31, 2018 and December 31, 2017 , we have met all margin call requirements and had no agency or non-agency repurchase agreements with original overnight maturities. Repurchase agreements are carried at cost, which approximates fair value due to their short-term maturities or floating rate coupons. As of March 31, 2018 and December 31, 2017 , our borrowings under repurchase agreements had the following collateral characteristics (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Collateral Type Borrowings Interest Rate Days Borrowings Interest Rate Days Agency securities $ 3,170,784 1.78 % 106 $ 3,307,662 1.54 % 114 Non-agency securities 569,380 2.93 % 18 556,057 2.72 % 24 U.S. Treasury securities 3,272 1.65 % 1 — N/A N/A Total repurchase agreements $ 3,743,436 1.96 % 92 $ 3,863,719 1.71 % 101 The following table summarizes our borrowings under repurchase arrangements as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Borrowings Outstanding Interest Rate Days Borrowings Outstanding Interest Rate Days ≤ 1 month $ 1,584,501 2.09 % 14 $ 1,341,712 1.91 % 17 > 1 to ≤ 2 months 955,061 1.80 % 43 1,334,493 1.55 % 40 > 2 to ≤ 3 months 342,533 1.95 % 78 295,204 1.76 % 76 > 3 to ≤ 6 months 510,378 1.71 % 155 334,372 1.51 % 123 > 6 to ≤ 12 months 85,963 2.04 % 301 292,938 1.57 % 256 > 12 months 265,000 2.18 % 568 265,000 1.80 % 658 Total repurchase agreements $ 3,743,436 1.96 % 92 $ 3,863,719 1.71 % 101 We had repurchase agreements with 36 financial institutions as of March 31, 2018 . Less than 4% of stockholders' equity was at risk due to collateral pledged in excess of borrowings under repurchase agreements with any one counterparty, with the top five counterparties representing approximately 17% of our stockholders' equity at risk as of March 31, 2018 . We had agency RMBS with fair values of $3.4 billion and $3.6 billion pledged as collateral against repurchase agreements as of March 31, 2018 and December 31, 2017 , respectively. We had non-agency securities with fair values of $0.8 billion and $0.7 billion pledged as collateral against repurchase agreements as of March 31, 2018 and December 31, 2017 , respectively.

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2018
Derivative Instruments [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivatives and Other Securities In connection with our risk management strategy, we mitigate our exposure to market risks, including interest rate risk, prepayment risk and credit risk, by entering into derivative and other hedging instrument contracts. We may enter into agreements for interest rate swaps, interest rate swaptions, interest rate cap or floor contracts and futures or forward contracts. We may also purchase or short TBA and U.S. Treasury securities, purchase or sell options on TBA securities or we may invest in other types of derivative securities, including synthetic total return swaps and credit default swaps. Our risk management strategy attempts to manage the overall risk of the portfolio and reduce fluctuations in net asset value. Derivatives have not been designated as hedging instruments. For additional information regarding our derivative instruments and our overall risk management strategy, please refer to the discussion of derivatives in Note 3. The table below presents the balance sheet location and fair value information for our derivatives outstanding as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 December 31, 2017 Derivative assets: Interest rate swaps $ 7,195 $ 4,894 Interest rate swaptions 12,820 6,728 TBA securities 9,711 3,090 Derivative assets, at fair value $ 29,726 $ 14,712 Derivative liabilities: TBA securities — 1,339 Credit default swaps — 3,115 Derivative liabilities, at fair value $ — $ 4,454 The following tables summarize the effect of our outstanding derivatives and other securities on our consolidated statements of operations during three months ended March 31, 2018 and 2017 (in thousands): For the Three Months Ended March 31, 2018 2017 Realized Gain on Periodic Settlements of Interest Rate Swaps, net Realized Gain (Loss) Unrealized Gain Realized Loss on Periodic Settlements of Interest Rate Swaps, net Realized Gain (Loss) Unrealized Gain (Loss) on Other Derivatives and Securities, net Interest rate swaps $ 358 $ 47,929 $ 2,120 $ (2,660 ) $ 26,021 $ (21,830 ) Interest rate swaptions — — 5,322 — — (428 ) TBA securities — (43,145 ) 7,959 — (24,290 ) 29,510 Short sales of U.S. Treasuries — (389 ) 16,503 — 251 (9,641 ) Credit default swaps — (1,648 ) 1,528 — (43 ) (457 ) Other — (11 ) 25 — 228 7 Total $ 358 $ 2,736 $ 33,457 $ (2,660 ) $ 2,167 $ (2,839 ) The following tables summarize changes in notional amounts for our outstanding derivatives and other securities during three months ended March 31, 2018 and 2017 (in thousands): December 31, 2017 Additions/ Long Positions Expirations/ Terminations/ Short Positions March 31, 2018 Interest rate swaps $ 3,530,000 100,000 — $ 3,630,000 Interest rate swaptions $ 425,000 75,000 — $ 500,000 TBA securities $ 1,704,386 5,057,110 (5,174,652 ) $ 1,586,844 U.S. Treasuries $ — 119,500 (94,500 ) $ 25,000 Short sales of U.S. Treasuries $ (846,700 ) 49,500 (60,500 ) $ (857,700 ) Credit default swaps $ 48,000 — (48,000 ) $ — December 31, 2016 Additions/ Long Positions Expirations/ Terminations/ Short Positions March 31, 2017 Interest rate swaps $ 2,975,000 75,000 (75,000 ) $ 2,975,000 Interest rate swaptions $ 150,000 — — $ 150,000 TBA securities $ 886,042 7,928,617 (6,774,908 ) $ 2,039,751 U.S. Treasuries $ 21,000 22,500 (43,500 ) $ — Short sales of U.S. Treasuries $ (511,000 ) 318,500 (1,172,000 ) $ (1,364,500 ) Credit default swaps $ 49,000 — (500 ) $ 48,500 Interest Rate Swap Agreements Our derivative portfolio includes interest rate swaps, which are used to manage our exposure to interest rate risk. Under our interest rate swaps, we typically pay a fixed rate and receive a floating rate based on LIBOR with terms usually ranging up to 15 years. As of March 31, 2018 and December 31, 2017 , we had interest rate swap agreements summarized in the table below (dollars in thousands). March 31, 2018 December 31, 2017 Notional Weighted Average Notional Weighted Average Current Maturity Date (1) Fixed (2) Receive (3) Maturity (Years) Fixed (2) Receive (3) Maturity (Years) ≤ 3 years $ 1,600,000 1.31 % 1.90 % 1.2 $ 1,500,000 1.26 % 1.46 % 1.3 > 3 to ≤ 5 years 935,000 1.77 % 1.94 % 3.9 985,000 1.79 % 1.47 % 4.0 > 5 to ≤ 7 years 400,000 1.98 % 1.79 % 5.4 350,000 1.78 % 1.40 % 5.7 > 7 years 695,000 2.26 % 1.96 % 9.6 695,000 2.26 % 1.47 % 9.9 Total $ 3,630,000 1.68 % 1.91 % 4.0 $ 3,530,000 1.65 % 1.46 % 4.2 ———————— (1) Includes swaps with an aggregate notional of $0.2 billion and $0.4 billion with deferred start dates averaging 0.0 years and 0.1 years from March 31, 2018 and December 31, 2017 , respectively. (2) Excluding forward starting swaps, the weighted average pay rate was 1.64% and 1.58% as of March 31, 2018 and December 31, 2017 , respectively. (3) Weighted average receive rate excludes impact of forward starting interest rate swaps. Interest Rate Swaption Agreements Our interest rate swaption agreements provide us the option to enter into interest rate swap agreements in the future where we would pay a fixed rate and receive LIBOR. The following tables present certain information about our interest rate swaption agreements as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Option Underlying Swap Current Option Expiration Date Cost Fair Value Weighted Average Years to Expiration Notional Amount Pay Rate Weighted Average Term (Years) ≤ 12 months $ 2,341 $ 3,979 0.7 $ 200,000 2.73 % 8.4 >12 to ≤ 24 months 2,623 3,077 1.2 125,000 2.86 % 8.4 > 24 months 7,951 5,764 3.2 175,000 2.87 % 8.7 Total / weighted average $ 12,915 $ 12,820 1.7 $ 500,000 2.81 % 8.5 December 31, 2017 Option Underlying Swap Current Option Expiration Date Cost Fair Value Weighted Average Years to Expiration Notional Amount Pay Rate Weighted Average Term (Years) < 12 months $ 2,111 $ 1,621 0.9 $ 175,000 2.71 % 8.6 >12 to ≤ 24 months 2,083 1,400 1.5 75,000 2.73 % 10.0 > 24 months 7,951 3,707 3.4 175,000 2.87 % 8.9 Total / weighted average $ 12,145 $ 6,728 2.0 $ 425,000 2.78 % 8.9 TBA Securities As of March 31, 2018 and December 31, 2017 , we had contracts to purchase (“long position”) and sell (“short position”) TBA securities on a forward basis, presented in the following table (in thousands): March 31, 2018 December 31, 2017 Purchase and Sale Contracts for TBA Securities Notional Amount (1) Fair Value (2) Notional Amount (1) Fair Value (2) TBA assets: Purchase of TBA securities $ 1,586,844 $ 9,711 $ 1,386,416 $ 3,089 Sale of TBA securities — — (1,200 ) 1 Total TBA assets 1,586,844 9,711 1,385,216 3,090 TBA liabilities: Purchase of TBA securities — — 319,170 (1,339 ) Sale of TBA securities — — — — Total TBA liabilities — — 319,170 (1,339 ) Total net TBA $ 1,586,844 $ 9,711 $ 1,704,386 $ 1,751 ———————— (1) Notional amount represents the par value or principal balance of the underlying agency security. (2) Fair value represents the current market value of the agency RMBS underlying the TBA contract as of period end, less the forward price to be paid for the underlying agency RMBS. U.S. Treasury Securities and Futures We purchase or sell short U.S. Treasury securities and U.S. Treasury futures contracts to mitigate our exposure to changes in interest rates. We had U.S. Treasury securities with a fair value of $24.9 million and a face amount of $25.0 million as of March 31, 2018 , which are presented as U.S. Treasury securities, at fair value on the consolidated balance sheets. In addition, we had obligations to return U.S. Treasury securities borrowed under reverse repurchase agreements accounted for as securities borrowing transactions with a fair value of $0.8 billion as of both March 31, 2018 and December 31, 2017 . The borrowed securities were collateralized by cash payments of $0.8 billion as of both March 31, 2018 and December 31, 2017 , which are presented as receivable under reverse repurchase agreements on the consolidated balance sheets. All changes in fair value of long and short U.S. Treasury securities and futures are recorded in realized and unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. Credit Risk-Related Contingent Features The use of derivatives creates exposure to credit risk relating to potential losses that could be recognized in the event that the counterparties to these instruments fail to perform their obligations under the contracts. We minimize this risk by limiting our counterparties for instruments which are not centrally cleared on a registered exchange to major financial institutions with acceptable credit ratings and monitoring positions with individual counterparties. In addition, both we and our counterparties may be required to pledge collateral for our derivatives, based on the market value, notional amount and remaining term of the derivative contract. In the event of a default by a counterparty, we may not receive payments provided for under the terms of our derivative agreements, and may have difficulty obtaining our assets pledged as collateral for our derivatives. The cash and cash equivalents pledged as collateral for our derivative instruments is included in restricted cash and cash equivalents on our consolidated balance sheets. Each of our ISDA Master Agreements contains provisions pursuant to which we are required to fully collateralize our obligations under our interest rate swap agreements if at any point the fair value of the swap represents a liability greater than the minimum transfer amount contained within our ISDA Master Agreements. We are also required to post initial collateral upon execution of certain of our swap transactions. If we breach any of these provisions, we will be required to settle our obligations under the agreements at their termination values, which approximates fair value. Further, each of our ISDA Master Agreements contain cross default provisions under which a default under certain of our other indebtedness in excess of a certain threshold causes an event of default under the agreement. Threshold amounts vary by lender. Following an event of default, we could be required to settle our obligations under the agreements at their termination values. Additionally, under certain of our ISDA Master Agreements, we could be required to settle our obligations under the agreements at their termination values if we fail to maintain either our REIT status or certain minimum equity thresholds, or comply with limits on our leverage above certain specified levels. As of March 31, 2018 , the fair value of the additional collateral that could be required to be posted as a result of the credit-risk related contingent features being triggered was not material to our consolidated financial statements. We did not have counterparty credit risk with any single counterparty in excess of 1% of our equity, as of March 31, 2018 under our non-centrally cleared interest rate swap and swaption agreements. In the case of centrally cleared interest rate swap contracts, we could be exposed to credit risk if the central clearing agency or a clearing member defaults on its respective obligation to perform under the contract. The risk is considered minimal, however, due to initial and daily exchange of mark to market margin requirements, the clearinghouse guarantee fund and other resources that are available in the event of a clearing member default.

Offsetting Assets and Liabiliti

Offsetting Assets and Liabilities (Notes)	3 Months Ended
	Mar. 31, 2018
Offsetting Assets and Liabilities [Abstract]
Offsetting Assets and Liabilities [Text Block]	Offsetting Assets and Liabilities Certain of our repurchase agreements and derivative transactions are governed by underlying agreements that generally provide for a right of offset under master netting arrangements (or similar agreements), including in the event of default or in the event of bankruptcy of either party to the transactions. We present our assets and liabilities subject to such arrangements on a gross basis in our consolidated balance sheets. The following tables present information about our assets and liabilities that are subject to such agreements and can potentially be offset on our consolidated balance sheets as of March 31, 2018 and December 31, 2017 (in thousands): Offsetting of Financial Assets and Derivative Assets: Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Financial Instruments Collateral Received (1) Net Amount March 31, 2018 Interest rate swaps and swaptions (2) $ 20,015 $ — $ 20,015 $ — $ (16,891 ) $ 3,124 TBA 9,711 — 9,711 — — 9,711 Receivable under reverse repurchase agreements 836,901 — 836,901 (666,306 ) (170,595 ) — Total $ 866,627 $ — $ 866,627 $ (666,306 ) $ (187,486 ) $ 12,835 December 31, 2017 Interest rate swaps and swaptions (2) $ 11,622 $ — $ 11,622 $ — $ (5,642 ) $ 5,980 TBA 3,090 — 3,090 (1,339 ) — 1,751 Receivable under reverse repurchase agreements 843,130 — 843,130 (725,319 ) (117,811 ) — Total $ 857,842 $ — $ 857,842 $ (726,658 ) $ (123,453 ) $ 7,731 Offsetting of Financial Liabilities and Derivative Liabilities: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Financial Instruments Collateral Pledged (1) Net Amount March 31, 2018 Repurchase agreements $ 3,743,436 $ — $ 3,743,436 $ (666,306 ) $ (3,077,130 ) $ — Total $ 3,743,436 $ — $ 3,743,436 $ (666,306 ) $ (3,077,130 ) $ — December 31, 2017 TBA $ 1,339 $ — $ 1,339 $ (1,339 ) $ — $ — Repurchase agreements 3,863,719 — 3,863,719 (725,319 ) (3,138,400 ) — Total $ 3,865,058 $ — $ 3,865,058 $ (726,658 ) $ (3,138,400 ) $ — ———————— (1) Includes cash and securities received / pledged as collateral, at fair value. Amounts presented are limited to collateral pledged sufficient to reduce the net amount to zero on a counterparty by counterparty basis, as applicable. Refer to Notes 3 and 4 for additional information regarding assets pledged. (2) Reported under derivative assets / liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 8 for a reconciliation of derivative assets / liabilities, at fair value to their sub-components.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Fair Value Measurements We have elected the option to account for all of our financial assets at fair value, with changes in fair value reflected in income during the period in which they occur. We have determined that this presentation most appropriately represents our financial results and position. Fair value is defined 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, based on the assumptions market participants would use when pricing an asset or liability. We determine the fair value of our agency and non-agency securities, including securities held as collateral, based upon fair value estimates obtained from multiple third-party pricing services and dealers. In determining fair value, third-party pricing sources use various valuation approaches, including market and income approaches. Factors used by third-party sources in estimating the fair value of an instrument may include observable inputs such as recent trading activity, credit data, volatility statistics, and other market data that are current as of the measurement date. The availability of observable inputs can vary by instrument and is affected by a wide variety of factors, including the type of instrument, whether the instrument is new and not yet established in the marketplace and other characteristics particular to the instrument. Third-party pricing sources may also use certain unobservable inputs, such as assumptions of future levels of prepayment, default and loss severity, especially when estimating fair values for securities with lower levels of recent trading activity. When possible, we make inquiries of third-party pricing sources to understand their use of significant inputs and assumptions. We review the various third-party fair value estimates and perform procedures to validate their reasonableness, including an analysis of the range of third-party estimates for each position, comparison to recent trade activity for similar securities, and our Manager's review for consistency with market conditions observed as of the measurement date. While we do not adjust prices we obtain from third-party pricing sources, we will exclude third-party prices for securities from our determination of fair value if we determine (based on our validation procedures and our Manager's market knowledge and expertise) that the price is significantly different than observable market data would indicate and we cannot obtain a satisfactory understanding from the third party source as to the significant inputs used to determine the price. We utilize a three-level valuation hierarchy for disclosure of fair value measurement. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. A financial instrument’s categorization within the hierarchy is based upon the lowest level of input that is significant to the fair value measurement. We use the results of the validation procedures described above as part of our determination of the appropriate fair value measurement hierarchy classification. The three levels of valuation hierarchy are defined as follows: • Level 1 Inputs - Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. • Level 2 Inputs - Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 Inputs - Significant unobservable market inputs that are supported by little or no market activity. The unobservable inputs represent the assumptions that market participants would use to price the assets and liabilities. The following tables present our financial instruments carried at fair value as of March 31, 2018 and December 31, 2017 , on the consolidated balance sheets by the valuation hierarchy, as described above (in thousands): March 31, 2018 Level 1 Level 2 Level 3 Total Assets Agency securities $ — $ 3,660,403 $ — $ 3,660,403 Non-agency securities — 833,681 — 833,681 U.S. Treasury securities 24,924 — — 24,924 Derivative assets — 29,726 — 29,726 Total $ 24,924 $ 4,523,810 $ — $ 4,548,734 Liabilities Obligation to return securities borrowed under reverse repurchase agreements 824,688 — — 824,688 Total $ 824,688 $ — $ — $ 824,688 December 31, 2017 Level 1 Level 2 Level 3 Total Assets Agency securities $ — $ 3,758,181 $ — $ 3,758,181 Non-agency securities — 872,084 — 872,084 Derivative assets — 14,712 — 14,712 Total $ — $ 4,644,977 $ — $ 4,644,977 Liabilities Derivative liabilities $ — $ 4,454 $ — $ 4,454 Obligation to return securities borrowed under reverse repurchase agreements 830,776 — — 830,776 Total $ 830,776 $ 4,454 $ — $ 835,230 Our agency and non-agency securities are valued using the various market data described above, which include inputs determined to be observable or whose significant value drivers are observable. Accordingly, our agency and non-agency securities are classified as Level 2 in the fair value hierarchy as of March 31, 2018 . For information regarding valuation of our derivative instruments, please refer to the discussion of derivative and other hedging instruments in Note 2. Our interest rate swaps and other derivatives are classified as Level 2 in the fair value hierarchy. The fair value of our obligation to return securities borrowed under reverse repurchase agreements is based upon the value of the underlying borrowed U.S. Treasury securities as of the reporting date. Both U.S. Treasury securities and our obligation to return borrowed U.S. Treasury securities are classified as Level 1 in the fair value hierarchy. Excluded from the table above are financial instruments, including cash and cash equivalents, restricted cash and cash equivalents, receivables, payables, borrowings under repurchase agreements, and debt secured by healthcare real estate investments, which are presented in our consolidated financial statements at cost. The cost basis of financial instruments with initial terms of less than one year are determined to approximate fair value, primarily due to the short duration of these instruments. The cost basis of floating rate borrowings with initial terms of greater than one year is determined to approximate fair value, primarily as such agreements have floating interest rates based on an index plus or minus a fixed spread and the fixed spread is generally consistent with those demanded in the market. The fair value of fixed rate secured debt is estimated by discounting the estimated future cash flows using the current rates at which similar loans would be made with similar credit ratings and for the same remaining maturities. We estimate the fair value of these instruments using Level 2 inputs. In addition to items that are measured at fair value on a recurring basis, we also have assets and liabilities in our balance sheet that are measured at fair value on a nonrecurring basis, including those acquired in business combinations. We have determined that the fair value measurements included in each of these assets and liabilities rely primarily on company-specific inputs and our assumptions about the use of the assets and settlement of liabilities, and that each of these fair value measurements generally incorporate Level 3 inputs. We estimate the fair value of real estate and related intangibles using the income approach and unobservable data such as net operating income and estimated capitalization and discount rates. We also consider local and national industry market data including comparable sales, and commonly engage an external real estate appraiser to assist us in our estimation of fair value. We estimate the fair value of secured debt assumed in business combinations using current interest rates at which similar borrowings could be obtained on the transaction date.

Other Assets (Notes)

Other Assets (Notes)	3 Months Ended
	Mar. 31, 2018
Other Assets [Abstract]
Other Assets Disclosure [Text Block]	Other Assets The following table summarizes our other assets as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Servicing advances $ — $ 324 Prepaid expenses 1,595 1,993 Accounts receivable 2,033 5,682 Goodwill 5,840 5,840 Other 6,557 9,403 Total other assets $ 16,025 $ 23,242

Other Liabilities (Notes)

Other Liabilities (Notes)	3 Months Ended
	Mar. 31, 2018
Other Liabilities [Abstract]
Other Liabilities Disclosure [Text Block]	Accounts Payable and Other Accrued Liabilities The following table summarizes our accounts payable and other accrued liabilities as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Cash collateral held $ 16,992 $ 5,642 Due to manager 1,473 1,451 Accrued interest 15,181 12,547 Other accounts payable and accrued expenses 11,258 13,952 Total accounts payable and other accrued liabilities $ 44,904 $ 33,592 Risk Mitigation Activities The Company’s previous investment in MSR exposes us to certain risks, including representation and warranty risk. Representation and warranty risk refers to the representations and warranties we made (or are deemed to have made) to the applicable investor (including, without limitation, the GSEs) regarding, among other things, the origination and servicing of mortgage loans with respect to which we had acquired MSR. We mitigated representation and warranty risk through our due diligence in connection with MSR acquisitions, including counterparty reviews and loan file reviews, as well as negotiated contractual protections from our MSR transaction counterparties with respect to prior origination and servicing. In connection with the sale of its servicing assets and remaining MSR in 2016 and 2017, Residential Credit Solutions, Inc. (“RCS”), the Company’s subsidiary that was previously engaged in mortgage servicing operations, retained certain risk exposure existing prior to the time of such sales, including representation and warranty risk.

Stockholder's Equity (Notes)

Stockholder's Equity (Notes)	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Attributable to Parent [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Stockholders’ Equity Redeemable Preferred Stock Pursuant to our charter, we are authorized to designate and issue up to 50.0 million shares of preferred stock in one or more classes or series. Our Board of Directors has designated 2.3 million shares as 8.125% Series A Cumulative Redeemable Preferred Stock (“Series A Preferred Stock”). As of March 31, 2018 , we had 47.8 million of authorized but unissued shares of preferred stock. Shares of our Series A Preferred Stock are redeemable at $25.00 per share plus accumulated and unpaid dividends (whether or not declared) exclusively at our option commencing on May 22, 2019, or earlier under certain circumstances intended to preserve our qualification as a REIT for Federal income tax purposes. Dividends are payable quarterly in arrears on the 15th day of each January, April, July and October. As of March 31, 2018 , we had declared all required quarterly dividends on the Series A Preferred Stock. Our Board of Directors may designate additional series of authorized preferred stock ranking junior to or in parity with the Series A Preferred Stock or designate additional shares of the Series A Preferred Stock and authorize the issuance of such shares. Our Series A Preferred Stock has no stated maturity and is not subject to any sinking fund or mandatory redemption. Common Stock Repurchase Program Our Board of Directors adopted a stock repurchase plan pursuant to which the Company is authorized to repurchase up to $100 million of its outstanding shares of common stock through December 31, 2018 . The Company may repurchase shares in the open market or privately negotiated transactions or pursuant to a trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities and Exchange Act of 1934, as amended. The Company intends to repurchase shares under the stock repurchase plan only when the repurchase price is less than its estimate of its then current net asset value per common share. The total amount of $100 million remains authorized and available for common stock repurchases as of March 31, 2018 . Shares of our common stock may be purchased in the open market, including through block purchases, or through privately negotiated transactions, or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The timing, manner, price and amount of any repurchases will be determined at our discretion and the program may be suspended, terminated or modified at any time for any reason. Long-Term Incentive Plan The Company sponsors the American Capital Mortgage Investment Corp. Amended and Restated Equity Incentive Plan (“Incentive Plan” or “plan”), as amended March 4, 2016, to provide for the issuance of equity-based awards, including stock options, restricted stock, restricted stock units (“RSU”) and unrestricted stock to our independent directors. We did not issue any shares of common stock related to the vesting of RSU awards during the three months ended March 31, 2018 , as any awards vested during the period were deferred to future periods. We have made no awards under the plan to our officers or the officers or employees of our Manager, and we no longer intend to issue RSUs to RCS employees. Net Income per Common Share Basic net income per common share is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share assumes the conversion, exercise or issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per share. Any shares subject to performance conditions that would not be issuable at period end, if that were the end of the contingency period, have been excluded from diluted net income per common share. Net income used in the numerator to calculate both basic and diluted EPS is the same. The number of shares used in the denominator of the calculation for basic and diluted EPS is different by an amount equal to the dilutive effect of stock awards issued to employees and directors. At-the-Market Offering Program During August 2017, we entered into agreements with sales agents to publicly offer and sell shares of our common stock in privately negotiated and/or at-the-market transactions from time-to-time up to an aggregate amount of $125 million of shares of our common stock. As of March 31, 2018 , we have not issued any shares under this program.

Subsequent Events (Notes)

Subsequent Events (Notes)	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On May 2, 2018, the Company, Annaly Capital Management, Inc., a Maryland corporation (“Annaly”), and Mountain Merger Sub Corporation, a Maryland corporation and a wholly owned subsidiary of Annaly (“Purchaser”), entered into an Agreement and Plan of Merger (the “Merger Agreement”). Pursuant to the Merger Agreement, and upon the terms and conditions thereof, Purchaser will commence an exchange offer (the “Offer”) to purchase all of the Company’s issued and outstanding shares of common stock, par value $0.01 per share (the “Company Common Stock”). In the Offer, holders of Company Common Stock will have the option to elect from among three forms of consideration for each share of Company Common Stock (subject to proration as described below): • $9.82 in cash and 0.9519 shares of Annaly common stock (the “Mixed Consideration Option”); • $19.65 in cash (the “Cash Consideration Option”); or • 1.9037 shares of Annaly common stock (the “Stock Consideration Option”). Holders of Company Common Stock who do not make a valid election will receive the Mixed Consideration Option for their shares of Company Common Stock. Holders who elect to receive the Cash Consideration Option or Stock Consideration Option will be subject to proration to ensure that approximately 50% of the aggregate consideration paid to holders of Company Common Stock in the Offer will be paid in the form of Annaly common stock and approximately 50% of the aggregate consideration paid to holders of Company Common Stock in the Offer will be paid in cash. Closing of the Offer is subject to the condition that a minimum number of shares be validly tendered and not validly withdrawn. Completion of the Offer is also subject to satisfaction or waiver of a number of other customary closing conditions, including the registration of shares of Annaly common stock to be issued in the transactions and the receipt of certain regulatory approvals. The Company cannot provide any assurance that the proposed transaction will close in a timely manner or at all. Immediately following the closing of the Offer, the Company will be merged with and into the Purchaser, with the Purchaser surviving the merger. In the merger, holders of Company Common Stock will have the right to receive, at their election, the Mixed Consideration Option, the Cash Consideration Option or the Stock Consideration Option, subject to proration as described above, and each share of the Company’s 8.125% Series A Cumulative Redeemable Preferred Stock, par value $0.01 per share (“Company Preferred Stock”), that is outstanding immediately prior to the merger will be converted into one share of a newly designated series of Annaly preferred stock, par value $0.01 per share, which will have rights, preferences and privileges and voting powers substantially the same as shares of the Company Preferred Stock. In connection with the execution of the Merger Agreement, the Company and our Manager entered into an amendment (the “Management Agreement Amendment”) to the management agreement, dated July 1, 2016 (the “Management Agreement”). The Management Agreement Amendment provides that one month following the completion of the transactions contemplated by the Merger Agreement, the Management Agreement will terminate, and as a result of the completion of the transactions contemplated by the Merger Agreement and the subsequent termination of the Management Agreement, the Company will reimburse the Manager for certain unpaid expenses, pay all accrued management fees then owed and pay the Manager a termination fee of approximately $41.7 million as and when specified in the Management Agreement Amendment.

(Policies)

(Policies)	3 Months Ended
	Mar. 31, 2018
Summary of Significant Accounting Policies [Abstract]
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Assets We have elected the option to account for all of our financial assets, including all mortgage-related investments, at estimated fair value, with changes in fair value reflected in income during the period in which they occur. In management's view, this election more appropriately reflects the results of our operations for a particular reporting period, as financial asset fair value changes are presented in a manner consistent with the presentation and timing of the fair value changes of hedging instruments. See Note 10 - Fair Value Measurements.
Revenue Recognition, Policy [Policy Text Block]	Interest Income Interest income is accrued based on the outstanding principal amount of the securities and their contractual terms. Premiums or discounts associated with the purchase of agency RMBS and non-agency securities of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method. We estimate long-term prepayment speeds using a third-party service and market data. Actual and anticipated prepayment experience is reviewed at least quarterly and effective yields are recalculated when differences arise between the previously estimated future prepayments and the amounts received plus currently anticipated future prepayments. If the actual and anticipated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield through the reporting date. At the time we purchase non-agency securities that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments, based on inputs and analysis received from external sources, internal models, and our judgment about interest rates, prepayment rates, the timing and amount of credit losses, and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment as adjusted for credit impairment, if any.
Property, Plant and Equipment, Policy [Policy Text Block]	Real Property Owned Tangible assets primarily consist of land, buildings and furniture, fixtures and equipment. Depreciable tangible assets are depreciated on a straight-line basis over their estimated useful lives, which can range from 3 years for furniture, fixtures and equipment to 40 years for buildings. On January 1, 2017 the Company adopted Accounting Standards Update (“ASU”) No. 2017-01, Clarifying the Definition of a Business (“ASU 2017-01”) which provides a framework to determine whether a transaction involves an asset, or a group of assets, or a business. ASU 2017-01 states that when substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the transaction should not be considered a business combination. The ASU also clarifies the requirements for a set of activities to be considered a business and narrows the definition of outputs that would lead to business combination accounting treatment. As a result of these changes, the Company expects that a majority of its future real estate acquisitions and dispositions will be deemed asset transactions rather than business combinations. For asset acquisitions subsequent to January 1, 2017, the Company records identifiable assets acquired, liabilities assumed and any associated noncontrolling interests at cost on a relative fair value basis, with no goodwill recognized and third-party transaction costs capitalized. The net book value of long-lived assets is reviewed quarterly on a property by property basis to determine if facts and circumstances suggest that the assets may be impaired or that depreciable lives may need to be changed. We consider external factors relating to each asset and the existence of a master lease that may link the cash flows of an individual asset to a larger portfolio of assets leased to the same tenant. If these factors and the projected undiscounted cash flows of the asset over the remaining depreciation period indicate that the asset will not be recoverable, the carrying value is reduced to the estimated fair market value. In addition, we are exposed to the risks inherent in investments in real estate and, in particular, the senior housing and healthcare industries. A downturn in these industries or in the real estate markets in which our properties are located could adversely affect the value of our properties and our ability to sell properties for a price or terms acceptable to us.
Goodwill and Intangible Assets, Policy [Policy Text Block]	Intangible Assets Intangible assets can include goodwill and identifiable intangible assets such as above or below market component of in-place leases and the value associated with the presence of in-place tenants or residents. Goodwill is calculated as the excess of consideration transferred over the estimated fair value of net assets recognized and represents the estimated future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Goodwill and intangible assets are included in other assets on the consolidated balance sheets and tested for impairment annually or more frequently if events and circumstances indicate that the asset might be impaired.
Revenue Recognition Leases, Operating [Policy Text Block]	Healthcare Real Estate Income Healthcare real estate income consists primarily of lease and rental income. For operating leases with minimum scheduled rent increases, the Company recognizes income on a straight line basis over the lease term when collectability is reasonably assured. Recognizing lease income on a straight line basis results in a difference in the timing of revenue amounts from what is contractually due. If the Company determines that collectability of straight line lease income is not reasonably assured, future revenue recognition is limited to amounts contractually owed and paid, and, when appropriate, an allowance for estimated losses is established. Resident rental income is recorded when services are rendered and includes resident room and care charges, community fees and other resident charges. Residency agreements are generally for a term of 30 days to one year, with resident fees billed monthly. Revenue for certain care-related services is recognized as the services are provided.
Noncontrolling Interest [Policy Text Block]	Noncontrolling Interests Arrangements with noncontrolling interest holders are reported as a component of equity separate from the Company’s stockholders' equity, recorded at the initial carrying amount, and increased or decreased for the noncontrolling interest’s share of net income or loss. Net income attributable to a noncontrolling interest is included in net income on the consolidated statements of operations.
Debt, Policy [Policy Text Block]	Deferred Loan Expenses We amortize deferred financing costs, which are reported within notes payable, net of deferred financing costs on our consolidated balance sheets, as a component of interest expense of the debt over the terms of the related borrowings using a method that approximates a level yield.
Repurchase Agreements, Valuation, Policy [Policy Text Block]	Repurchase Agreements We finance the acquisition of agency RMBS and non-agency securities through repurchase transactions under master repurchase agreements. We account for repurchase transactions as collateralized financing transactions which are carried at their contractual amounts, including accrued interest, as specified in the respective transaction agreements. The contractual amounts approximate fair value due to their short-term maturities or floating rate coupons.
Repurchase and Resale Agreements Policy [Policy Text Block]	Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivatives below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the consolidated balance sheets based on the value of the underlying borrowed securities as of the reporting date. The fair value of our reverse repurchase agreements is assumed to equal cost as they generally mature daily or have interest rates that are reset daily.
Derivatives, Policy [Policy Text Block]	Derivatives We utilize a risk management strategy, under which we may use a variety of derivative instruments to mitigate our exposure to market risks, including interest rate risk, prepayment risk, extension risk and credit risk. The objective of our risk management strategy is to reduce fluctuations in net asset value over a range of market conditions. The principal instruments that we currently use are interest rate swaps and options to enter into interest rate swaps (“interest rate swaptions”). We also utilize forward contracts for the purchase or sale of agency RMBS, or to-be-announced forward (“TBA”) contracts, and short sales of U.S. Treasury securities and U.S. Treasury futures contracts. We may also purchase or sell options on TBA securities and utilize other types of derivative instruments. We also enter into TBA contracts as a means of investing in and financing agency RMBS (thereby increasing our “at risk” leverage) or as a means of disposing of or reducing our exposure to agency RMBS (thereby reducing our “at risk” leverage). Pursuant to TBA contracts, we agree to purchase or sell, for future delivery, agency RMBS with certain principal and interest terms and certain types of collateral, but the particular agency RMBS to be delivered are not identified until shortly before the TBA settlement date. We may also choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting short or long position (referred to as a “pair off”), net settling the paired off positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date. This transaction is commonly referred to as a “dollar roll.” The agency RMBS purchased or sold for a forward settlement date are typically priced at a discount to agency RMBS for settlement in the current month. This difference (or discount) is referred to as the “price drop.” The price drop is the economic equivalent of net interest carry income on the underlying agency RMBS over the roll period (interest income less implied financing cost) and is commonly referred to as “dollar roll income (loss).” Consequently, forward purchases of agency RMBS and dollar roll transactions represent a form of off-balance sheet financing. We present all derivative instruments as either assets or liabilities at fair value on our consolidated balance sheets and report all changes in fair value in earnings in our consolidated statements of operations in unrealized gain (loss) on other derivatives and securities, net during the period in which they occur. Derivatives in a gain position are reported as derivative assets at fair value and derivatives in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with each counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized in the event counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral based on daily market value changes. We also attempt to minimize our risk of loss by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with short-term borrowings made under our repurchase agreement and other financing facilities. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one, three or six-month LIBOR (“payer swaps”) with terms up to 15 years. The floating rate we receive under our swap agreements has the effect of offsetting the repricing characteristics of our repurchase agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over-the-counter (“OTC”) market. Swap agreements entered into subsequent to May 2013 are centrally cleared through the Chicago Mercantile Exchange (“CME”), a registered commodities exchange. We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references observable market inputs, including LIBOR, swap rates and the forward yield curve, to produce the daily settlement price. Our centrally cleared swaps require that we post an “initial margin” to our counterparties for an amount determined by the CME, which is generally intended to be set at a level sufficient to protect the CME from the maximum estimated single-day price movement in that market participant’s contracts. We also exchange cash “variation margin” with our counterparties on our centrally cleared swaps based upon daily changes in the fair value as measured by the CME. Beginning in the first quarter of 2017, as a result of a CME amendment to its rule book governing central clearing activities, the daily exchange of variation margin associated with a CME centrally cleared derivative instrument is legally characterized as the daily settlement of the derivative instrument itself, as opposed to a pledge of collateral. Accordingly, beginning in 2017, we account for the daily receipt or payment of variation margin associated with our centrally cleared interest rate swaps as a direct reduction to the carrying value of the interest rate swap derivative asset or liability, respectively. Beginning in 2017, the carrying amount of centrally cleared interest rate swaps reflected in our consolidated balance sheets is equal to the unsettled fair value of such instruments. We estimate the fair value of our “non-centrally cleared” interest rate swaps based on valuations obtained from third-party pricing services and the swap counterparty (collectively, “third-party valuations”). The third-party valuations are model-driven using observable inputs, including LIBOR, swap rates and the forward yield curve. We also consider the creditworthiness of both us and our counterparties and the impact of netting and credit enhancement provisions contained in each derivative agreement, such as collateral postings. All of our “non-centrally cleared” interest rate swaps are subject to bilateral collateral arrangements. Consequently, no credit valuation adjustment was made in determining the fair value of such instruments. The payment of periodic settlements of net interest on interest rate swaps is reported in realized loss on periodic settlements of interest rate swaps, net in our consolidated statements of operations. Cash payments received or paid for the early termination of an interest rate swap agreement are recorded as realized loss on other derivatives and securities, net in our consolidated statements of operations. Changes in fair value of our interest rate swap agreements are reported in unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. The interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay or receive interest rates in the future. The premium paid for interest rate swaptions is reported as a derivative asset in our consolidated balance sheets. We estimate the fair value of interest rate swaptions based on the fair value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option. The difference between the premium and the fair value of the swaption is reported in unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid and reported in realized loss on other derivatives and securities, net in our consolidated statements of operations. If we exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the fair value of the underlying interest rate swap and the premium paid and reported in realized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. Interest rate swaption agreements are privately negotiated in the OTC market and are not subject to central clearing. We estimate the fair value of our interest rate swaption agreements based on model-driven valuations obtained from third-party pricing services and the swaption counterparty. These estimates incorporate observable inputs and include the fair value of the future interest rate swaps that we have the option to enter into, as well as the remaining length of time that we have to exercise the options, adjusted for non-performance risk, if any. TBA securities TBA securities are forward contracts for the purchase (“long position”) or sale (“short position”) of agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific agency RMBS delivered into the contract upon the settlement date, published each month by the Securities Industry and Financial Markets Association, are not known at the time of the transaction. We may enter into TBA contracts as a means of hedging against short-term changes in interest rates. We may also enter into TBA dollar roll transactions to finance agency RMBS purchases. We account for all TBA contracts as derivatives since we cannot assert that it is probable at the inception and throughout the term of the contract that it will not settle net and will result in physical delivery of an agency security when it is issued. A TBA dollar roll transaction is a series of derivative transactions. The net settlement of a TBA contract is reported as realized gain (loss) on other derivatives and securities, net and changes in the fair value of our TBA contracts are reported as unrealized gain (loss) on other derivatives and securities, net in our consolidated statements of operations. We estimate the fair value of TBA securities based on similar methods used to value our agency RMBS. U.S. Treasury securities We purchase or sell short U.S. Treasury securities and U.S. Treasury futures contracts to help mitigate the potential impact of changes in interest rates on the performance of our portfolio. Realized gains and losses associated with purchases and short sales of U.S. Treasury securities and U.S. Treasury futures contracts are recognized in realized gain (loss) on other derivatives and securities, net, and unrealized gains and losses are recognized in unrealized gain (loss) on other derivatives and securities, net on our consolidated statements of operations.

Agency Securities (Tables)

Agency Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Agency Securities [Abstract]
Agency Securities [Table Text Block]	The following tables summarize our investments in agency RMBS as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Fannie Mae Freddie Mac Total Agency RMBS: Par value $ 2,393,236 $ 1,196,372 $ 3,589,608 Unamortized premium 118,223 63,641 181,864 Amortized cost 2,511,459 1,260,013 3,771,472 Gross unrealized gains 688 281 969 Gross unrealized losses (75,332 ) (36,706 ) (112,038 ) Agency RMBS, at fair value $ 2,436,815 $ 1,223,588 $ 3,660,403 Weighted average coupon as of March 31, 2018 3.61 % 3.73 % 3.65 % Weighted average yield as of March 31, 2018 2.82 % 2.96 % 2.87 % Weighted average yield for the three months ended March 31, 2018 2.94 % 3.12 % 3.00 % March 31, 2018 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 3,698,545 $ 718 $ (111,935 ) $ 3,587,328 Adjustable rate 72,927 251 (103 ) 73,075 Total Agency RMBS $ 3,771,472 $ 969 $ (112,038 ) $ 3,660,403 December 31, 2017 Fannie Mae Freddie Mac Total Agency RMBS: Par value $ 2,485,055 $ 1,117,551 $ 3,602,606 Unamortized premium 127,008 63,466 190,474 Amortized cost 2,612,063 1,181,017 3,793,080 Gross unrealized gains 3,876 1,149 5,025 Gross unrealized losses (28,364 ) (11,560 ) (39,924 ) Agency RMBS, at fair value $ 2,587,575 $ 1,170,606 $ 3,758,181 Weighted average coupon as of December 31, 2017 3.63 % 3.75 % 3.67 % Weighted average yield as of December 31, 2017 2.78 % 2.89 % 2.82 % Weighted average yield for the year ended December 31, 2017 2.67 % 2.69 % 2.68 % December 31, 2017 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 3,717,285 $ 3,707 $ (39,924 ) $ 3,681,068 Adjustable rate 75,795 1,318 — 77,113 Total Agency RMBS $ 3,793,080 $ 5,025 $ (39,924 ) $ 3,758,181
Summary Of Agency Securities Estimated Weighted Average Life Classifications Text Block	The following table summarizes our agency RMBS as of March 31, 2018 and December 31, 2017 according to their estimated weighted average life classification (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Estimated Weighted Fair Value Amortized Cost Yield Coupon Fair Value Amortized Cost Yield Coupon Less than or equal to three years $ 42,371 $ 43,132 2.10 % 3.93 % $ 40,404 $ 40,815 2.06 % 3.92 % Greater than three years and less than or equal to five years 489,624 498,048 2.39 % 3.15 % 534,299 535,608 2.38 % 3.19 % Greater than five years and less than or equal to 10 years 2,872,403 2,967,793 2.94 % 3.74 % 3,149,565 3,182,468 2.90 % 3.75 % Greater than 10 years 256,005 262,499 3.15 % 3.55 % 33,913 34,189 2.98 % 3.50 % Total $ 3,660,403 $ 3,771,472 2.87 % 3.65 % $ 3,758,181 $ 3,793,080 2.82 % 3.67 %
Schedule of Realized Gain (Loss) [Table Text Block]	The following table summarizes our net realized gains and losses from the sale of agency RMBS during three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Proceeds from agency securities sold $ 220,435 $ 208,457 Less agency securities sold, at cost (222,375 ) (208,669 ) Realized loss on agency securities, net $ (1,940 ) $ (212 ) Gross realized gains on sale of agency securities $ 14 $ 1,270 Gross realized losses on sale of agency securities (1,954 ) (1,482 ) Realized loss on agency securities, net $ (1,940 ) $ (212 ) The following table summarizes our net realized gains from the sale of non-agency securities during three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Proceeds from non-agency securities sold $ 89,901 $ 260,473 Increase in receivable for securities sold — 5,748 Less: non-agency securities sold, at cost (85,747 ) (253,507 ) Realized gain on non-agency securities, net $ 4,154 $ 12,714 Gross realized gain on sale of non-agency securities $ 4,155 $ 12,864 Gross realized loss on sale of non-agency securities (1 ) (150 ) Realized gain on non-agency securities, net $ 4,154 $ 12,714
Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block]	The following tables summarize our agency RMBS pledged as collateral under financing and derivative agreements by type as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Fannie Mae Freddie Mac Total Fair Value of Agency Securities Pledged Under: Financing agreements $ 2,294,011 $ 1,140,080 $ 3,434,091 Derivative agreements 80 460 540 Total fair value 2,294,091 1,140,540 3,434,631 Accrued interest on pledged agency RMBS 6,800 3,476 10,276 Total Fair Value of Agency RMBS Pledged and Accrued Interest $ 2,300,891 $ 1,144,016 $ 3,444,907 December 31, 2017 Fannie Mae Freddie Mac Total Fair Value of Agency Securities Pledged Under: Financing agreements $ 2,443,591 $ 1,137,587 $ 3,581,178 Derivative agreements 84 606 690 Total fair value 2,443,675 1,138,193 3,581,868 Accrued interest on pledged agency RMBS 7,132 3,399 10,531 Total Fair Value of Agency RMBS Pledged and Accrued Interest $ 2,450,807 $ 1,141,592 $ 3,592,399
Schedules Of Securities Pledged As Collateral Under Repurchase Agreement [Text Block] [Table Text Block]	The following table summarizes our agency RMBS pledged as collateral under financings agreements, by remaining maturity, including securities pledged related to sold but not yet settled securities, as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Remaining Maturity Fair Value Amortized Cost Accrued Interest Fair Value Amortized Cost Accrued Interest 30 days or less $ 1,102,225 $ 1,136,865 $ 3,262 $ 940,788 $ 949,282 $ 2,765 31 - 59 days 985,955 1,015,732 2,974 1,298,331 1,311,882 3,818 60 - 90 days 359,108 370,094 1,096 261,823 262,908 785 Greater than 90 days 986,803 1,019,398 2,944 1,080,236 1,091,195 3,161 Total $ 3,434,091 $ 3,542,089 $ 10,276 $ 3,581,178 $ 3,615,267 $ 10,529 The following table summarizes our non-agency securities pledged as collateral under repurchase agreements, by remaining maturity, including securities pledged related to sold but not yet settled securities, as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Remaining Maturity Fair Value Amortized Accrued Interest Fair Value Amortized Accrued Interest 30 days or less $ 686,521 $ 614,635 $ 1,052 $ 585,943 $ 517,750 $ 815 31 - 59 days 60,500 50,754 75 97,537 82,105 145 60 - 90 days 13,123 10,311 17 59,798 58,651 135 Total $ 760,144 $ 675,700 $ 1,144 $ 743,278 $ 658,506 $ 1,095

Non-Agency Securities (Tables)

Non-Agency Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Securities [Table Text Block]	The following tables summarize our non-agency securities as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Fair Value Gross Unrealized Amortized Cost Premium (Discount) Par/ Current Face Weighted Average Category Gains Losses Coupon (1) Yield Prime $ 139,841 $ 9,529 $ (77 ) $ 130,389 $ (13,262 ) $ 143,651 3.86 % 5.89 % CRT 300,338 16,465 (81 ) 283,954 13,258 270,696 5.50 % 5.68 % Alt-A 277,083 50,162 (628 ) 227,549 (109,122 ) 336,671 2.94 % 9.21 % Option-ARM 84,683 12,790 — 71,893 (20,305 ) 92,198 2.11 % 6.79 % Subprime 13,337 873 — 12,464 (664 ) 13,128 5.20 % 5.92 % CMBS 18,399 171 (85 ) 18,313 (187 ) 18,500 5.68 % 6.04 % Total $ 833,681 $ 89,990 $ (871 ) $ 744,562 $ (130,282 ) $ 874,844 3.91 % 6.92 % ———————— (1) Coupon rates are floating, except for $11.4 million , $5.6 million , $12.0 million , $13.3 million and $18.4 million fair value of fixed-rate prime, CRT, Alt-A, subprime and CMBS non-agency securities, respectively, as of March 31, 2018 . December 31, 2017 Fair Value Gross Unrealized Amortized Cost Premium (Discount) Par/ Current Face Weighted Average Category Gains Losses Coupon (1) Yield Prime $ 143,329 $ 9,342 $ (12 ) $ 133,999 $ (13,893 ) $ 147,892 3.77 % 5.66 % CRT 322,819 18,346 — 304,473 16,011 288,462 5.34 % 5.23 % Alt-A 286,953 51,123 (774 ) 236,604 (112,305 ) 348,909 2.69 % 8.93 % Option-ARM 86,886 13,114 — 73,772 (21,044 ) 94,816 1.79 % 6.58 % Subprime 13,374 929 — 12,445 (683 ) 13,128 5.20 % 5.97 % CMBS 18,723 387 — 18,336 (164 ) 18,500 5.68 % 6.03 % Total $ 872,084 $ 93,241 $ (786 ) $ 779,629 $ (132,078 ) $ 911,707 3.73 % 6.59 % ———————— (1) Coupon rates are floating, except for $11.8 million , $0.9 million , $12.2 million , $13.4 million and $18.7 million fair value of fixed-rate prime, CRT, Alt-A, subprime and CMBS non-agency securities, respectively, as of December 31, 2017 .
Schedule of Non-Agency Securities by Weighted Average Life [Table Text Block]	The following table summarizes our non-agency securities at fair value, by their estimated weighted average life classifications as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Estimated Weighted Average Life Fair Value Amortized Cost Coupon Yield Fair Value Amortized Cost Coupon Yield ≤ 5 years $ 285,566 $ 244,884 3.33 % 8.44 % $ 302,797 $ 258,501 3.11 % 8.31 % > 5 to ≤ 7 years 258,753 226,721 4.17 % 7.05 % 398,712 361,649 4.33 % 5.97 % > 7 years 289,362 272,957 4.35 % 5.43 % 170,575 159,479 3.61 % 5.18 % Total $ 833,681 $ 744,562 3.91 % 6.92 % $ 872,084 $ 779,629 3.73 % 6.59 %
Realized Gain (Loss) on Investments [Table Text Block]	The following table summarizes our net realized gains and losses from the sale of agency RMBS during three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Proceeds from agency securities sold $ 220,435 $ 208,457 Less agency securities sold, at cost (222,375 ) (208,669 ) Realized loss on agency securities, net $ (1,940 ) $ (212 ) Gross realized gains on sale of agency securities $ 14 $ 1,270 Gross realized losses on sale of agency securities (1,954 ) (1,482 ) Realized loss on agency securities, net $ (1,940 ) $ (212 ) The following table summarizes our net realized gains from the sale of non-agency securities during three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Proceeds from non-agency securities sold $ 89,901 $ 260,473 Increase in receivable for securities sold — 5,748 Less: non-agency securities sold, at cost (85,747 ) (253,507 ) Realized gain on non-agency securities, net $ 4,154 $ 12,714 Gross realized gain on sale of non-agency securities $ 4,155 $ 12,864 Gross realized loss on sale of non-agency securities (1 ) (150 ) Realized gain on non-agency securities, net $ 4,154 $ 12,714
Schedules Of Securities Pledged As Collateral Under Repurchase Agreement [Text Block] [Table Text Block]	The following table summarizes our agency RMBS pledged as collateral under financings agreements, by remaining maturity, including securities pledged related to sold but not yet settled securities, as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Remaining Maturity Fair Value Amortized Cost Accrued Interest Fair Value Amortized Cost Accrued Interest 30 days or less $ 1,102,225 $ 1,136,865 $ 3,262 $ 940,788 $ 949,282 $ 2,765 31 - 59 days 985,955 1,015,732 2,974 1,298,331 1,311,882 3,818 60 - 90 days 359,108 370,094 1,096 261,823 262,908 785 Greater than 90 days 986,803 1,019,398 2,944 1,080,236 1,091,195 3,161 Total $ 3,434,091 $ 3,542,089 $ 10,276 $ 3,581,178 $ 3,615,267 $ 10,529 The following table summarizes our non-agency securities pledged as collateral under repurchase agreements, by remaining maturity, including securities pledged related to sold but not yet settled securities, as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Remaining Maturity Fair Value Amortized Accrued Interest Fair Value Amortized Accrued Interest 30 days or less $ 686,521 $ 614,635 $ 1,052 $ 585,943 $ 517,750 $ 815 31 - 59 days 60,500 50,754 75 97,537 82,105 145 60 - 90 days 13,123 10,311 17 59,798 58,651 135 Total $ 760,144 $ 675,700 $ 1,144 $ 743,278 $ 658,506 $ 1,095

Investments in Real Property (T

Investments in Real Property (Tables)	3 Months Ended
	Mar. 31, 2018
Real Estate Investments, Net [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table summarizes our real estate investments net of accumulated depreciation as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Buildings and improvements $ 253,649 $ 233,407 Furniture, fixtures and equipment 15,719 14,537 Less: accumulated depreciation (9,593 ) (7,592 ) Buildings, furniture, fixtures and equipment, net of accumulated depreciation 259,775 240,352 Land 17,201 16,641 Goodwill 5,840 5,840 Net working capital (1) 16,369 18,994 Total real estate assets $ 299,185 $ 281,827
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	The following table presents the components of net income from our real property investments during the three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Lease income $ 5,706 $ 2,253 Rental income 2,054 1,062 Healthcare real estate income 7,760 3,315 Interest expense 2,089 1,173 Depreciation 2,001 771 Tenant expenses 1,425 709 Other 280 — Healthcare real estate expense 5,795 2,653 Net healthcare investment income $ 1,964 $ 662
Schedule of Long-term Debt Instruments [Table Text Block]	The following is a summary of our notes payable activity for the three months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 2017 Beginning balance $ 186,500 $ 66,527 Debt issued and assumed, net of deferred financing costs 15,938 19,581 Amortization of deferred financing costs 58 193 Principal repayments (510 ) (93 ) Ending balance $ 201,986 $ 86,208
Schedule of Minimum Lease Payments Receivable [Table Text Block]	At March 31, 2018 , future minimum lease payments receivable related to our healthcare and senior living facilities are as follows (dollars in thousands): March 31, 2018 2018 $ 15,301 2019 20,764 2020 21,191 2021 21,627 2022 22,073 Thereafter 193,233 Total $ 294,189

Repurchase Agreements (Tables)

Repurchase Agreements (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Repurchase Agreements [Abstract]
Schedule of Debt [Table Text Block]	As of March 31, 2018 and December 31, 2017 , our borrowings under repurchase agreements had the following collateral characteristics (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Collateral Type Borrowings Interest Rate Days Borrowings Interest Rate Days Agency securities $ 3,170,784 1.78 % 106 $ 3,307,662 1.54 % 114 Non-agency securities 569,380 2.93 % 18 556,057 2.72 % 24 U.S. Treasury securities 3,272 1.65 % 1 — N/A N/A Total repurchase agreements $ 3,743,436 1.96 % 92 $ 3,863,719 1.71 % 101 The following table summarizes our borrowings under repurchase arrangements as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Weighted Average Weighted Average Borrowings Outstanding Interest Rate Days Borrowings Outstanding Interest Rate Days ≤ 1 month $ 1,584,501 2.09 % 14 $ 1,341,712 1.91 % 17 > 1 to ≤ 2 months 955,061 1.80 % 43 1,334,493 1.55 % 40 > 2 to ≤ 3 months 342,533 1.95 % 78 295,204 1.76 % 76 > 3 to ≤ 6 months 510,378 1.71 % 155 334,372 1.51 % 123 > 6 to ≤ 12 months 85,963 2.04 % 301 292,938 1.57 % 256 > 12 months 265,000 2.18 % 568 265,000 1.80 % 658 Total repurchase agreements $ 3,743,436 1.96 % 92 $ 3,863,719 1.71 % 101

Derivatives (Tables)

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The table below presents the balance sheet location and fair value information for our derivatives outstanding as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 December 31, 2017 Derivative assets: Interest rate swaps $ 7,195 $ 4,894 Interest rate swaptions 12,820 6,728 TBA securities 9,711 3,090 Derivative assets, at fair value $ 29,726 $ 14,712 Derivative liabilities: TBA securities — 1,339 Credit default swaps — 3,115 Derivative liabilities, at fair value $ — $ 4,454
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	The following tables summarize the effect of our outstanding derivatives and other securities on our consolidated statements of operations during three months ended March 31, 2018 and 2017 (in thousands): For the Three Months Ended March 31, 2018 2017 Realized Gain on Periodic Settlements of Interest Rate Swaps, net Realized Gain (Loss) Unrealized Gain Realized Loss on Periodic Settlements of Interest Rate Swaps, net Realized Gain (Loss) Unrealized Gain (Loss) on Other Derivatives and Securities, net Interest rate swaps $ 358 $ 47,929 $ 2,120 $ (2,660 ) $ 26,021 $ (21,830 ) Interest rate swaptions — — 5,322 — — (428 ) TBA securities — (43,145 ) 7,959 — (24,290 ) 29,510 Short sales of U.S. Treasuries — (389 ) 16,503 — 251 (9,641 ) Credit default swaps — (1,648 ) 1,528 — (43 ) (457 ) Other — (11 ) 25 — 228 7 Total $ 358 $ 2,736 $ 33,457 $ (2,660 ) $ 2,167 $ (2,839 )
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following tables summarize changes in notional amounts for our outstanding derivatives and other securities during three months ended March 31, 2018 and 2017 (in thousands): December 31, 2017 Additions/ Long Positions Expirations/ Terminations/ Short Positions March 31, 2018 Interest rate swaps $ 3,530,000 100,000 — $ 3,630,000 Interest rate swaptions $ 425,000 75,000 — $ 500,000 TBA securities $ 1,704,386 5,057,110 (5,174,652 ) $ 1,586,844 U.S. Treasuries $ — 119,500 (94,500 ) $ 25,000 Short sales of U.S. Treasuries $ (846,700 ) 49,500 (60,500 ) $ (857,700 ) Credit default swaps $ 48,000 — (48,000 ) $ — December 31, 2016 Additions/ Long Positions Expirations/ Terminations/ Short Positions March 31, 2017 Interest rate swaps $ 2,975,000 75,000 (75,000 ) $ 2,975,000 Interest rate swaptions $ 150,000 — — $ 150,000 TBA securities $ 886,042 7,928,617 (6,774,908 ) $ 2,039,751 U.S. Treasuries $ 21,000 22,500 (43,500 ) $ — Short sales of U.S. Treasuries $ (511,000 ) 318,500 (1,172,000 ) $ (1,364,500 ) Credit default swaps $ 49,000 — (500 ) $ 48,500
Schedule Of Interest Rate Swap Agreement By Remaining Maturity [Table Text Block]	As of March 31, 2018 and December 31, 2017 , we had interest rate swap agreements summarized in the table below (dollars in thousands). March 31, 2018 December 31, 2017 Notional Weighted Average Notional Weighted Average Current Maturity Date (1) Fixed (2) Receive (3) Maturity (Years) Fixed (2) Receive (3) Maturity (Years) ≤ 3 years $ 1,600,000 1.31 % 1.90 % 1.2 $ 1,500,000 1.26 % 1.46 % 1.3 > 3 to ≤ 5 years 935,000 1.77 % 1.94 % 3.9 985,000 1.79 % 1.47 % 4.0 > 5 to ≤ 7 years 400,000 1.98 % 1.79 % 5.4 350,000 1.78 % 1.40 % 5.7 > 7 years 695,000 2.26 % 1.96 % 9.6 695,000 2.26 % 1.47 % 9.9 Total $ 3,630,000 1.68 % 1.91 % 4.0 $ 3,530,000 1.65 % 1.46 % 4.2 ———————— (1) Includes swaps with an aggregate notional of $0.2 billion and $0.4 billion with deferred start dates averaging 0.0 years and 0.1 years from March 31, 2018 and December 31, 2017 , respectively. (2) Excluding forward starting swaps, the weighted average pay rate was 1.64% and 1.58% as of March 31, 2018 and December 31, 2017 , respectively. (3) Weighted average receive rate excludes impact of forward starting interest rate swaps.
Schedule of Interest Rate Swaption Agreements Outstandin [Table Text Block]	The following tables present certain information about our interest rate swaption agreements as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 Option Underlying Swap Current Option Expiration Date Cost Fair Value Weighted Average Years to Expiration Notional Amount Pay Rate Weighted Average Term (Years) ≤ 12 months $ 2,341 $ 3,979 0.7 $ 200,000 2.73 % 8.4 >12 to ≤ 24 months 2,623 3,077 1.2 125,000 2.86 % 8.4 > 24 months 7,951 5,764 3.2 175,000 2.87 % 8.7 Total / weighted average $ 12,915 $ 12,820 1.7 $ 500,000 2.81 % 8.5 December 31, 2017 Option Underlying Swap Current Option Expiration Date Cost Fair Value Weighted Average Years to Expiration Notional Amount Pay Rate Weighted Average Term (Years) < 12 months $ 2,111 $ 1,621 0.9 $ 175,000 2.71 % 8.6 >12 to ≤ 24 months 2,083 1,400 1.5 75,000 2.73 % 10.0 > 24 months 7,951 3,707 3.4 175,000 2.87 % 8.9 Total / weighted average $ 12,145 $ 6,728 2.0 $ 425,000 2.78 % 8.9
Schedule of Long and Short Position of Derivative Instruments [Table Text Block]	TBA Securities As of March 31, 2018 and December 31, 2017 , we had contracts to purchase (“long position”) and sell (“short position”) TBA securities on a forward basis, presented in the following table (in thousands): March 31, 2018 December 31, 2017 Purchase and Sale Contracts for TBA Securities Notional Amount (1) Fair Value (2) Notional Amount (1) Fair Value (2) TBA assets: Purchase of TBA securities $ 1,586,844 $ 9,711 $ 1,386,416 $ 3,089 Sale of TBA securities — — (1,200 ) 1 Total TBA assets 1,586,844 9,711 1,385,216 3,090 TBA liabilities: Purchase of TBA securities — — 319,170 (1,339 ) Sale of TBA securities — — — — Total TBA liabilities — — 319,170 (1,339 ) Total net TBA $ 1,586,844 $ 9,711 $ 1,704,386 $ 1,751 ———————— (1) Notional amount represents the par value or principal balance of the underlying agency security. (2) Fair value represents the current market value of the agency RMBS underlying the TBA contract as of period end, less the forward price to be paid for the underlying agency RMBS.

Offsetting Assets and Liabili27

Offsetting Assets and Liabilities Offsetting Financial and Derivative Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Offsetting of Financial Assets and Derivative Assets [Abstract]
Offsetting Assets [Table Text Block]	Offsetting of Financial Assets and Derivative Assets: Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Financial Instruments Collateral Received (1) Net Amount March 31, 2018 Interest rate swaps and swaptions (2) $ 20,015 $ — $ 20,015 $ — $ (16,891 ) $ 3,124 TBA 9,711 — 9,711 — — 9,711 Receivable under reverse repurchase agreements 836,901 — 836,901 (666,306 ) (170,595 ) — Total $ 866,627 $ — $ 866,627 $ (666,306 ) $ (187,486 ) $ 12,835 December 31, 2017 Interest rate swaps and swaptions (2) $ 11,622 $ — $ 11,622 $ — $ (5,642 ) $ 5,980 TBA 3,090 — 3,090 (1,339 ) — 1,751 Receivable under reverse repurchase agreements 843,130 — 843,130 (725,319 ) (117,811 ) — Total $ 857,842 $ — $ 857,842 $ (726,658 ) $ (123,453 ) $ 7,731
Offsetting Liabilities [Table Text Block]	Offsetting of Financial Liabilities and Derivative Liabilities: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Financial Instruments Collateral Pledged (1) Net Amount March 31, 2018 Repurchase agreements $ 3,743,436 $ — $ 3,743,436 $ (666,306 ) $ (3,077,130 ) $ — Total $ 3,743,436 $ — $ 3,743,436 $ (666,306 ) $ (3,077,130 ) $ — December 31, 2017 TBA $ 1,339 $ — $ 1,339 $ (1,339 ) $ — $ — Repurchase agreements 3,863,719 — 3,863,719 (725,319 ) (3,138,400 ) — Total $ 3,865,058 $ — $ 3,865,058 $ (726,658 ) $ (3,138,400 ) $ — ———————— (1) Includes cash and securities received / pledged as collateral, at fair value. Amounts presented are limited to collateral pledged sufficient to reduce the net amount to zero on a counterparty by counterparty basis, as applicable. Refer to Notes 3 and 4 for additional information regarding assets pledged. (2) Reported under derivative assets / liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 8 for a reconciliation of derivative assets / liabilities, at fair value to their sub-components.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	The following tables present our financial instruments carried at fair value as of March 31, 2018 and December 31, 2017 , on the consolidated balance sheets by the valuation hierarchy, as described above (in thousands): March 31, 2018 Level 1 Level 2 Level 3 Total Assets Agency securities $ — $ 3,660,403 $ — $ 3,660,403 Non-agency securities — 833,681 — 833,681 U.S. Treasury securities 24,924 — — 24,924 Derivative assets — 29,726 — 29,726 Total $ 24,924 $ 4,523,810 $ — $ 4,548,734 Liabilities Obligation to return securities borrowed under reverse repurchase agreements 824,688 — — 824,688 Total $ 824,688 $ — $ — $ 824,688 December 31, 2017 Level 1 Level 2 Level 3 Total Assets Agency securities $ — $ 3,758,181 $ — $ 3,758,181 Non-agency securities — 872,084 — 872,084 Derivative assets — 14,712 — 14,712 Total $ — $ 4,644,977 $ — $ 4,644,977 Liabilities Derivative liabilities $ — $ 4,454 $ — $ 4,454 Obligation to return securities borrowed under reverse repurchase agreements 830,776 — — 830,776 Total $ 830,776 $ 4,454 $ — $ 835,230

Other Assets (Tables)

Other Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Other Assets [Abstract]
Schedule of Other Assets [Table Text Block]	The following table summarizes our other assets as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Servicing advances $ — $ 324 Prepaid expenses 1,595 1,993 Accounts receivable 2,033 5,682 Goodwill 5,840 5,840 Other 6,557 9,403 Total other assets $ 16,025 $ 23,242

Other Liabilities (Tables)

Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Other Liabilities [Abstract]
Other Liabilities [Table Text Block]	The following table summarizes our accounts payable and other accrued liabilities as of March 31, 2018 and December 31, 2017 (dollars in thousands): March 31, 2018 December 31, 2017 Cash collateral held $ 16,992 $ 5,642 Due to manager 1,473 1,451 Accrued interest 15,181 12,547 Other accounts payable and accrued expenses 11,258 13,952 Total accounts payable and other accrued liabilities $ 44,904 $ 33,592

Agency Securities Agency securi

Agency Securities Agency securities, at fair value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 3,660,403		$ 3,758,181
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Agency Securities at Par	3,589,608		3,602,606
Agency Securities Unamortized Premium	181,864		190,474
Agency Securities Amortized Cost	3,771,472		3,793,080
Agency Securities, Gross Unrealized Gains	969		5,025
Agency Securities, Gross Unrealized Losses	(112,038)		(39,924)
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 3,660,403		$ 3,758,181
Weighted Average Coupon Rate	3.65%		3.67%
Weighted Average Yield Percentage	2.87%		2.82%
Weighted Average Yield Percentage for Period	3.00%	2.68%
Agency Securities [Member] | Fixed Rate Residential Mortgage [Member]
Schedule of Available-for-sale Securities [Line Items]
Agency Securities Amortized Cost	$ 3,698,545		$ 3,717,285
Agency Securities, Gross Unrealized Gains	718		3,707
Agency Securities, Gross Unrealized Losses	(111,935)		(39,924)
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	3,587,328		3,681,068
Agency Securities [Member] | Adjustable Rate Residential Mortgage [Member]
Schedule of Available-for-sale Securities [Line Items]
Agency Securities Amortized Cost	72,927		75,795
Agency Securities, Gross Unrealized Gains	251		1,318
Agency Securities, Gross Unrealized Losses	(103)		0
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	73,075		77,113
Agency Securities [Member] | Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Agency Securities at Par	2,393,236		2,485,055
Agency Securities Unamortized Premium	118,223		127,008
Agency Securities Amortized Cost	2,511,459		2,612,063
Agency Securities, Gross Unrealized Gains	688		3,876
Agency Securities, Gross Unrealized Losses	(75,332)		(28,364)
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 2,436,815		$ 2,587,575
Weighted Average Coupon Rate	3.61%		3.63%
Weighted Average Yield Percentage	2.82%		2.78%
Weighted Average Yield Percentage for Period	2.94%	2.67%
Agency Securities [Member] | Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Agency Securities at Par	$ 1,196,372		$ 1,117,551
Agency Securities Unamortized Premium	63,641		63,466
Agency Securities Amortized Cost	1,260,013		1,181,017
Agency Securities, Gross Unrealized Gains	281		1,149
Agency Securities, Gross Unrealized Losses	(36,706)		(11,560)
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 1,223,588		$ 1,170,606
Weighted Average Coupon Rate	3.73%		3.75%
Weighted Average Yield Percentage	2.96%		2.89%
Weighted Average Yield Percentage for Period	3.12%	2.69%

Agency Securities Weighted Aver

Agency Securities Weighted Average Life of Agency Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 3,660,403		$ 3,758,181
WeightedAverageLifeofAgencySecurities	8 years	7 years 6 months
Prepayment Rate Of Remaining Life Of Investment Portfolio	7.60%		8.40%
Agency Securities [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 3,660,403		$ 3,758,181
Agency Securities Amortized Cost	$ 3,771,472		$ 3,793,080
Weighted Average Yield Percentage	2.87%		2.82%
Weighted Average Coupon Rate	3.65%		3.67%
Agency Securities [Member] | Less than Three Years [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 42,371		$ 40,404
Agency Securities Amortized Cost	$ 43,132		$ 40,815
Weighted Average Yield Percentage	2.10%		2.06%
Weighted Average Coupon Rate	3.93%		3.92%
Agency Securities [Member] | Greater Than Three Years and Less Than or Equal to Five Years [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 489,624		$ 534,299
Agency Securities Amortized Cost	$ 498,048		$ 535,608
Weighted Average Yield Percentage	2.39%		2.38%
Weighted Average Coupon Rate	3.15%		3.19%
Agency Securities [Member] | Greater than 5 years and less than or equal to 10 years [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 2,872,403		$ 3,149,565
Agency Securities Amortized Cost	$ 2,967,793		$ 3,182,468
Weighted Average Yield Percentage	2.94%		2.90%
Weighted Average Coupon Rate	3.74%		3.75%
Agency Securities [Member] | Greater than 10 years [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 256,005		$ 33,913
Agency Securities Amortized Cost	$ 262,499		$ 34,189
Weighted Average Yield Percentage	3.15%		2.98%
Weighted Average Coupon Rate	3.55%		3.50%

Agency Securities Realized Gain

Agency Securities Realized Gains and Losses on Agency Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Gain (Loss) on Sales of Mortgage Backed Securities (MBS)	$ (1,940)	$ (212)
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Sale of Agency Securities, Debt	220,435	208,457
Cost of Sale of Agency Securities	(222,375)	(208,669)
Agency Securities, Gross Realized Gains	14	1,270
Agency Securities, Gross Realized Losses	(1,954)	(1,482)
Gain (Loss) on Sales of Mortgage Backed Securities (MBS)	$ (1,940)	$ (212)

Agency Securities Agency Secu34

Agency Securities Agency Securities Pledged Under Borrowing Agreements (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total Fair Value Of Agency Securities Pledged And Accrued Interest	$ 3,444,907	$ 3,592,399
Fannie Mae [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total Fair Value Of Agency Securities Pledged And Accrued Interest	2,300,891	2,450,807
Freddie Mac [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total Fair Value Of Agency Securities Pledged And Accrued Interest	1,144,016	1,141,592
Agency Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	3,434,631	3,581,868
Agency Securities Pledged As Collateral Accrued Interest	10,276	10,531
Agency Securities [Member] | Fannie Mae [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	2,294,091	2,443,675
Agency Securities Pledged As Collateral Accrued Interest	6,800	7,132
Agency Securities [Member] | Freddie Mac [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	1,140,540	1,138,193
Agency Securities Pledged As Collateral Accrued Interest	3,476	3,399
Repurchase Agreements [Member] | Agency Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	3,434,091	3,581,178
Agency Securities Pledged As Collateral Accrued Interest	10,276	10,529
Repurchase Agreements [Member] | Agency Securities [Member] | Fannie Mae [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	2,294,011	2,443,591
Repurchase Agreements [Member] | Agency Securities [Member] | Freddie Mac [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	1,140,080	1,137,587
Under Derivative Agreements [Member] | Agency Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	540	690
Under Derivative Agreements [Member] | Agency Securities [Member] | Fannie Mae [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	80	84
Under Derivative Agreements [Member] | Agency Securities [Member] | Freddie Mac [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	$ 460	$ 606

Agency Securities Agency Secu35

Agency Securities Agency Securities Pledged As Collateral by Maturity Date (Details) - Agency Securities [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	$ 3,434,631	$ 3,581,868
Pledged Assets, Not Separately Reported, Other	10,276	10,531
Securities Sold under Agreements to Repurchase [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	3,434,091	3,581,178
Agency Securities Pledged As Collateral Amortized Cost	3,542,089	3,615,267
Pledged Assets, Not Separately Reported, Other	10,276	10,529
Securities Sold under Agreements to Repurchase [Member] | Maturity up to 30 days [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	1,102,225	940,788
Agency Securities Pledged As Collateral Amortized Cost	1,136,865	949,282
Pledged Assets, Not Separately Reported, Other	3,262	2,765
Securities Sold under Agreements to Repurchase [Member] | Maturity 31 To 59 Days [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	985,955	1,298,331
Agency Securities Pledged As Collateral Amortized Cost	1,015,732	1,311,882
Pledged Assets, Not Separately Reported, Other	2,974	3,818
Securities Sold under Agreements to Repurchase [Member] | Maturity 60 To 90 Days [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	359,108	261,823
Agency Securities Pledged As Collateral Amortized Cost	370,094	262,908
Pledged Assets, Not Separately Reported, Other	1,096	785
Securities Sold under Agreements to Repurchase [Member] | Maturity over 90 days [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Agency Securities Pledged As Collateral	986,803	1,080,236
Agency Securities Pledged As Collateral Amortized Cost	1,019,398	1,091,195
Pledged Assets, Not Separately Reported, Other	$ 2,944	$ 3,161

Non-Agency Securities Schedule

Non-Agency Securities Schedule of Non-Agency Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment [Line Items]
Non-Agency Securities, at Fair Value	$ 833,681	$ 872,084
Prime [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	139,841	143,329
Gross Unrealized Gain on Non-Agency Securities	9,529	9,342
Gross Unrealized Loss on Non-Agency Securities	(77)	(12)
Non-Agency Securities, at Amortized Cost	130,389	133,999
Debt Instrument, Unamortized Discount	(13,262)	(13,893)
Non-Agency Securities at Par	$ 143,651	$ 147,892
Weighted Average Coupon Rate	3.86%	3.77%
Weighted Average Yield Percentage	5.89%	5.66%
Fixed Rate Non-Agency Security	$ 11,400	$ 11,800
Credit Risk Transfer [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	300,338	322,819
Gross Unrealized Gain on Non-Agency Securities	16,465	18,346
Gross Unrealized Loss on Non-Agency Securities	(81)	0
Non-Agency Securities, at Amortized Cost	283,954	304,473
Debt Instrument, Unamortized Discount	13,258	16,011
Non-Agency Securities at Par	$ 270,696	$ 288,462
Weighted Average Coupon Rate	5.50%	5.34%
Weighted Average Yield Percentage	5.68%	5.23%
Fixed Rate Non-Agency Security	$ 5,600
Alt-A [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	277,083	$ 286,953
Gross Unrealized Gain on Non-Agency Securities	50,162	51,123
Gross Unrealized Loss on Non-Agency Securities	(628)	(774)
Non-Agency Securities, at Amortized Cost	227,549	236,604
Debt Instrument, Unamortized Discount	(109,122)	(112,305)
Non-Agency Securities at Par	$ 336,671	$ 348,909
Weighted Average Coupon Rate	2.94%	2.69%
Weighted Average Yield Percentage	9.21%	8.93%
Fixed Rate Non-Agency Security	$ 12,000	$ 12,200
Option-Arm [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	84,683	86,886
Gross Unrealized Gain on Non-Agency Securities	12,790	13,114
Gross Unrealized Loss on Non-Agency Securities	0	0
Non-Agency Securities, at Amortized Cost	71,893	73,772
Debt Instrument, Unamortized Discount	(20,305)	(21,044)
Non-Agency Securities at Par	$ 92,198	$ 94,816
Weighted Average Coupon Rate	2.11%	1.79%
Weighted Average Yield Percentage	6.79%	6.58%
Subprime [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	$ 13,337	$ 13,374
Gross Unrealized Gain on Non-Agency Securities	873	929
Gross Unrealized Loss on Non-Agency Securities	0	0
Non-Agency Securities, at Amortized Cost	12,464	12,445
Debt Instrument, Unamortized Discount	(664)	(683)
Non-Agency Securities at Par	$ 13,128	$ 13,128
Weighted Average Coupon Rate	5.20%	5.20%
Weighted Average Yield Percentage	5.92%	5.97%
Fixed Rate Non-Agency Security	$ 13,300	$ 13,400
Commercial Mortgage Backed Securities [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	18,399	18,723
Gross Unrealized Gain on Non-Agency Securities	171	387
Gross Unrealized Loss on Non-Agency Securities	(85)	0
Non-Agency Securities, at Amortized Cost	18,313	18,336
Debt Instrument, Unamortized Discount	(187)	(164)
Non-Agency Securities at Par	$ 18,500	$ 18,500
Weighted Average Coupon Rate	5.68%	5.68%
Weighted Average Yield Percentage	6.04%	6.03%
Fixed Rate Non-Agency Security	$ 18,400	$ 18,700
Non-Agency Securities [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value		872,084
Gross Unrealized Gain on Non-Agency Securities	89,990	93,241
Gross Unrealized Loss on Non-Agency Securities	(871)	(786)
Non-Agency Securities, at Amortized Cost	744,562	779,629
Debt Instrument, Unamortized Discount	(130,282)	(132,078)
Non-Agency Securities at Par	$ 874,844	$ 911,707
Weighted Average Coupon Rate	3.91%	3.73%
Weighted Average Yield Percentage	6.92%	6.59%

Non-Agency Securities Weighted

Non-Agency Securities Weighted Average Life of Non-Agency Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment [Line Items]
Non-Agency Securities, at Fair Value	$ 833,681	$ 872,084
Non-Agency Securities [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value		872,084
Non-Agency Securities, at Amortized Cost	$ 744,562	$ 779,629
Weighted Average Coupon Rate	3.91%	3.73%
Weighted Average Yield Percentage	6.92%	6.59%
Less Than or Equal to Five Years [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	$ 285,566	$ 302,797
Non-Agency Securities, at Amortized Cost	$ 244,884	$ 258,501
Weighted Average Coupon Rate	3.33%	3.11%
Weighted Average Yield Percentage	8.44%	8.31%
Greater Than Five Years and Less Than or Equal to Seven Year [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	$ 258,753	$ 398,712
Non-Agency Securities, at Amortized Cost	$ 226,721	$ 361,649
Weighted Average Coupon Rate	4.17%	4.33%
Weighted Average Yield Percentage	7.05%	5.97%
Greater Than Seven Years [Member]
Investment [Line Items]
Non-Agency Security, at Fair Value	$ 289,362	$ 170,575
Non-Agency Securities, at Amortized Cost	$ 272,957	$ 159,479
Weighted Average Coupon Rate	4.35%	3.61%
Weighted Average Yield Percentage	5.43%	5.18%

Non-Agency Securities Realized

Non-Agency Securities Realized Gains (Losses) from Sale of Non-Agency Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Gain (Loss) on Investments [Line Items]
Proceeds from sale of non-agency securities	$ (89,902)	$ (260,473)
Realized gain on non-agency securities, net	4,154	12,714
Non-Agency Securities [Member]
Gain (Loss) on Investments [Line Items]
Proceeds from sale of non-agency securities	89,901	260,473
Increase (Decrease) in Other Receivables	0	5,748
Cost of Sale of Non-Agency Securities	(85,747)	(253,507)
Available-for-sale Securities, Gross Realized Gains	(4,155)	(12,864)
Available-for-sale Securities, Gross Realized Losses	(1)	(150)
Realized gain on non-agency securities, net	$ 4,154	$ 12,714

Non-Agency Securities Non-Agenc

Non-Agency Securities Non-Agency Securities Pledged Under Repurchase Agreements (Details) - Non-Agency Securities [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 760,144	$ 743,278
Short-term Debt [Member]
Short-term Debt [Line Items]
Security Owned and Pledged as Collateral, Fair Value	760,144	743,278
Agency Securities Pledged As Collateral Amortized Cost	675,700	658,506
Pledged Assets, Not Separately Reported, Other	1,144	1,095
Repurchase Agreements [Member]
Short-term Debt [Line Items]
Security Owned and Pledged as Collateral, Fair Value	800,000	700,000
Maturity up to 30 days [Member] | Short-term Debt [Member]
Short-term Debt [Line Items]
Security Owned and Pledged as Collateral, Fair Value	686,521	585,943
Agency Securities Pledged As Collateral Amortized Cost	614,635	517,750
Pledged Assets, Not Separately Reported, Other	1,052	815
Maturity 31 To 59 Days [Member] | Short-term Debt [Member]
Short-term Debt [Line Items]
Security Owned and Pledged as Collateral, Fair Value	60,500	97,537
Agency Securities Pledged As Collateral Amortized Cost	50,754	82,105
Pledged Assets, Not Separately Reported, Other	75	145
Maturity 60 To 90 Days [Member] | Short-term Debt [Member]
Short-term Debt [Line Items]
Security Owned and Pledged as Collateral, Fair Value	13,123	59,798
Agency Securities Pledged As Collateral Amortized Cost	10,311	58,651
Pledged Assets, Not Separately Reported, Other	$ 17	$ 135

Non-Agency Securities Non-Age40

Non-Agency Securities Non-Agency Portfolio Characteristics (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Prime [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 139,841	$ 143,329
Weighted Average Coupon Rate	3.86%	3.77%
Credit Risk Transfer [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 300,338	$ 322,819
Weighted Average Coupon Rate	5.50%	5.34%
Credit Risk Transfer [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	1.25%
Underlying Collateral Coupon	3.615%
Credit Risk Transfer [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	8.80%
Underlying Collateral Coupon	4.337%
Alt-A [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 277,083	$ 286,953
Weighted Average Coupon Rate	2.94%	2.69%
Alt-A [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	1.9515%
Underlying Collateral Coupon	3.639%
Alt-A [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	6.50%
Underlying Collateral Coupon	5.781%
Option-Arm [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 84,683	$ 86,886
Weighted Average Coupon Rate	2.11%	1.79%
Option-Arm [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	2.012%
Underlying Collateral Coupon	3.532%
Option-Arm [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	2.612%
Underlying Collateral Coupon	4.528%
Subprime [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 13,337	$ 13,374
Weighted Average Coupon Rate	5.20%	5.20%
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 18,399	$ 18,723
Weighted Average Coupon Rate	5.68%	5.68%
2012- 2015 [Member] | Prime [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 0
Pre-2013 [Member] | Subprime [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-Agency Security, at Fair Value	$ 13,300
Pre-2013 [Member] | Subprime [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	5.006%
Underlying Collateral Coupon	5.532%
Pre-2013 [Member] | Subprime [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	5.456%
Underlying Collateral Coupon	5.712%
2013 [Member] | Commercial Mortgage Backed Securities [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	5.205%
Underlying Collateral Coupon	4.546%
2013 [Member] | Commercial Mortgage Backed Securities [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	6.55%
Floating Coupon [Member] | Prime [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	2.472%
Underlying Collateral Coupon	3.473%
Floating Coupon [Member] | Prime [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	6.50%
Underlying Collateral Coupon	5.038%
External Credit Rating, Non Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of Non-Investment Grade Non-Agency Securities	87.00%

Investments in Real Property 41

Investments in Real Property Investment Activity (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Real Estate Properties [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings	$ 20,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Equipment	900
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land	600
Buildings and Improvements, Gross	253,649	$ 233,407
Furniture and Fixtures, Gross	15,719	14,537
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	9,593	7,592
Property, Plant and Equipment, Net	259,775	240,352
Land	17,201	16,641
Goodwill	5,840	5,840
Assets, Current	16,369	18,994
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	299,185	281,827
Real Estate Investment [Member]
Real Estate Properties [Line Items]
Cash Equivalents, at Carrying Value	14,700	16,100
Deferred Rent Receivables, Net	3,400	$ 2,800
KANSAS | Joint Venture [Member]
Real Estate Properties [Line Items]
Real Estate Investments, Net	$ 21,500

Investments in Real Property He

Investments in Real Property Healthcare Notes Payable (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 205,000		$ 189,000
Debt Instrument, Fee Amount	2,700		2,500
Notes and Loans Payable	201,986	$ 86,208	186,500	$ 66,527
Long-term Debt, Percentage Bearing Variable Interest, Amount	66,400		50,300
Proceeds from Issuance of Secured Debt	15,938	19,774
Debt Instrument, Periodic Payment, Principal	510	93
Long-term Debt, Percentage Bearing Fixed Interest, Amount	138,300		138,800
Long-term Debt, Fair Value	198,000		$ 190,000
Real Estate Investment [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Secured Debt	15,938	19,581
Payments of Financing Costs	58	(193)
Debt Instrument, Periodic Payment, Principal	$ 510	$ (93)
Weighted Average [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayment Terms	P25Y4M	P25Y7M
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	4.63%		4.34%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	3.81%		3.80%
Variable Rate [Domain] | Weighted Average [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayment Terms	P0Y11M	P0Y9M

Investments in Real Property Ne

Investments in Real Property Net Income (Loss) from Healthcare Real Estate Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Investment Income [Line Items]
Real Estate Revenue, Net	$ 7,760	$ 3,315
Interest Expense	17,053	10,165
Depreciation	2,059	771
Real Estate Investment [Member]
Net Investment Income [Line Items]
Operating Leases, Income Statement, Lease Revenue	5,706	2,253
Rental Income, Nonoperating	2,054	1,062
Real Estate Revenue, Net	7,760	3,315
Interest Expense	2,089	1,173
Depreciation	2,001	771
Noninterest Expense	1,425	709
Real Estate Tax Expense	280	0
Other Expense from Real Estate Partnership Operations	5,795	2,653
Net Income (Loss) from Real Estate Investment Partnership, Attributable to Parent	$ 1,964	$ 662

Investments in Real Property Fu

Investments in Real Property Future Minimum Lease Payments Receivable (Details) - Triple Net [Member] $ in Thousands	Mar. 31, 2018USD ($)
Schedule of Minimum Lease Payments Receivable [Line Items]
Operating Leases, Future Minimum Payments Receivable, Current	$ 15,301
Operating Leases, Future Minimum Payments Receivable, in Two Years	20,764
Operating Leases, Future Minimum Payments Receivable, in Three Years	21,191
Operating Leases, Future Minimum Payments Receivable, in Four Years	21,627
Operating Leases, Future Minimum Payments Receivable, in Five Years	22,073
Operating Leases, Future Minimum Payments Receivable, Thereafter	193,233
Operating Leases, Future Minimum Payments Receivable	$ 294,189

Repurchase Agreements Repurchas

Repurchase Agreements Repurchase Agreements by Collateral Type (Details) - Repurchase Agreements [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Securities Sold under Agreements to Repurchase	$ 3,743,436	$ 3,863,719
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.96%	1.71%
Weighted Average Days to Maturity	P92D	P101D
Agency Securities [Member]
Short-term Debt [Line Items]
Securities Sold under Agreements to Repurchase	$ 3,170,784	$ 3,307,662
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.78%	1.54%
Weighted Average Days to Maturity	P106D	P114D
Non-Agency Securities [Member]
Short-term Debt [Line Items]
Securities Sold under Agreements to Repurchase	$ 569,380	$ 556,057
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.93%	2.72%
Weighted Average Days to Maturity	P18D	P24D
US Treasury Securities [Member]
Short-term Debt [Line Items]
Securities Sold under Agreements to Repurchase	$ 3,272	$ 0
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.65%
Weighted Average Days to Maturity	P1D

Repurchase Agreements Schedule

Repurchase Agreements Schedule of Repurchase Agreements (Details) - Repurchase Agreements [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 3,743,436	$ 3,863,719
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.96%	1.71%
Weighted Average Days to Maturity	P92D	P101D
Maturity up to 30 days [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 1,584,501	$ 1,341,712
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.09%	1.91%
Weighted Average Days to Maturity	P14D	P17D
Maturity Thirty One To Sixty Days [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 955,061	$ 1,334,493
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.80%	1.55%
Weighted Average Days to Maturity	P43D	P40D
Maturity 61 To 90 Days [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 342,533	$ 295,204
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.95%	1.76%
Weighted Average Days to Maturity	P78D	P76D
Maturity 90 to 180 Days [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 510,378	$ 334,372
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.71%	1.51%
Weighted Average Days to Maturity	P155D	P123D
Maturity 180 to 270 days [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 85,963	$ 292,938
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.04%	1.57%
Weighted Average Days to Maturity	P301D	P256D
Greater Than 12 Months [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 265,000	$ 265,000
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.18%	1.80%
Weighted Average Days to Maturity	P568D	P658D
US Treasury Securities [Member]
Statement [Line Items]
Securities Sold under Agreements to Repurchase	$ 3,272	$ 0
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.65%
Weighted Average Days to Maturity	P1D

Repurchase Agreements Repurch47

Repurchase Agreements Repurchase Agreements Narrative (Details)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Number of Repo Counterparties	36
Secured Debt, Repurchase Agreements	$ 3,743,436,000	$ 3,863,719,000
Risk Of Repurchase Agreement To Stockholders Equity	4.00%
Agency Securities [Member]
Agency Securities Pledged As Collateral	$ 3,434,631,000	3,581,868,000
Non-Agency Securities [Member]
Agency Securities Pledged As Collateral	760,144,000	743,278,000
Repurchase Agreements [Member] | Agency Securities [Member]
Agency Securities Pledged As Collateral		3,600,000,000
Repurchase Agreements [Member] | Non-Agency Securities [Member]
Agency Securities Pledged As Collateral	$ 800,000,000	$ 700,000,000
Top 5 Repo Counterparties [Member]
Risk Of Repurchase Agreement To Stockholders Equity	17.00%

Derivatives Fair Value of Outst

Derivatives Fair Value of Outstanding Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative assets, at fair value	$ 29,726	$ 14,712
Derivative Liabilities	0	4,454
Interest Rate Swap Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, at fair value	7,195	4,894
Payer Swaption [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, at fair value	12,820	6,728
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, at fair value	9,711	3,090
Derivative Liabilities	0	1,339
Credit Default Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 0	$ 3,115

Derivatives Effect of Derivativ

Derivatives Effect of Derivatives on Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	$ 358	$ (2,660)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	2,736	2,167
Unrealized Gain (Loss) on Derivatives	33,457	(2,839)
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	358	(2,660)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	47,929	26,021
Unrealized Gain (Loss) on Derivatives	2,120	(21,830)
Interest Rate Swaption [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	0	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0	0
Unrealized Gain (Loss) on Derivatives	5,322	(428)
Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	0	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(43,145)	(24,290)
Unrealized Gain (Loss) on Derivatives	7,959	29,510
Credit Default Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	0	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1,648)	(43)
Unrealized Gain (Loss) on Derivatives	1,528	(457)
Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	0	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(11)	228
Unrealized Gain (Loss) on Derivatives	25	7
Short [Member] | US Treasury Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on periodic interest settlements of interest rate swaps, net	0	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(389)	251
Unrealized Gain (Loss) on Derivatives	$ 16,503	$ (9,641)

Derivatives Change in Derivativ

Derivatives Change in Derivative Notional Amounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative [Line Items]
Notional Amount of Derivatives	$ (400,000)
Notional Amount of Derivatives	(200,000)
Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	(3,530,000)	$ (2,975,000)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	100,000	75,000
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	0	(75,000)
Notional Amount of Derivatives	(3,630,000)	(2,975,000)
Interest Rate Swaption [Member]
Derivative [Line Items]
Notional Amount of Derivatives	(425,000)	(150,000)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	75,000	0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	0	0
Notional Amount of Derivatives	(500,000)	(150,000)
Forward Contracts [Member]
Derivative [Line Items]
Notional Amount of Derivatives	(1,704,386)	(886,042)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	5,057,110	7,928,617
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(5,174,652)	(6,774,908)
Notional Amount of Derivatives	(1,586,844)	(2,039,751)
US Treasury Securities [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	(21,000)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	119,500	22,500
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(94,500)	(43,500)
Notional Amount of Derivatives	(25,000)	0
Credit Default Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	(48,000)	(49,000)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0	0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(48,000)	(500)
Notional Amount of Derivatives	0	(48,500)
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Notional Amount of Derivatives	(846,700)	(511,000)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	49,500	318,500
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(60,500)	(1,172,000)
Notional Amount of Derivatives	$ (857,700)	$ (1,364,500)

Derivatives Interest Rate Swap

Derivatives Interest Rate Swap Agreements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative Liability	$ 0	$ (4,454)
Notional Amount of Derivatives	200,000	400,000
Derivative Asset	29,726	14,712
Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	3,630,000	3,530,000	$ 2,975,000	$ 2,975,000
Derivative Asset	$ 7,195	$ 4,894
Weighted Average Days to Maturity	13 days	1 month
Interest Rate Derivative Not Designated As Hedging Instruments Average Fixed Pay Rate	1.68%	1.65%
Interest Rate Derivative Not Designated As Hedging Instruments Average receive Rate	1.91%	1.46%
Derivative, Average Remaining Maturity	4 years	4 years 2 months
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	$ 1,600,000	$ 1,500,000
Interest Rate Derivative Not Designated As Hedging Instruments Average Fixed Pay Rate	1.31%	1.26%
Interest Rate Derivative Not Designated As Hedging Instruments Average receive Rate	1.90%	1.46%
Derivative, Average Remaining Maturity	1 year 2 months	1 year 4 months
Greater Than Three Years and Less Than or Equal to Five Years [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	$ 935,000	$ 985,000
Interest Rate Derivative Not Designated As Hedging Instruments Average Fixed Pay Rate	1.77%	1.79%
Interest Rate Derivative Not Designated As Hedging Instruments Average receive Rate	1.94%	1.47%
Derivative, Average Remaining Maturity	3 years 11 months	4 years
Greater Than Five Years and Less than or Equal to Seven Years [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	$ 400,000	$ 350,000
Interest Rate Derivative Not Designated As Hedging Instruments Average Fixed Pay Rate	1.98%	1.78%
Interest Rate Derivative Not Designated As Hedging Instruments Average receive Rate	1.79%	1.40%
Derivative, Average Remaining Maturity	5 years 5 months	5 years 8 months
Greater Than Seven Years [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	$ 695,000	$ 695,000
Interest Rate Derivative Not Designated As Hedging Instruments Average Fixed Pay Rate	2.26%	2.26%
Interest Rate Derivative Not Designated As Hedging Instruments Average receive Rate	1.96%	1.47%
Derivative, Average Remaining Maturity	9 years 7 months	9 years 11 months
Maximum [Member]
Derivative [Line Items]
Percent of Equity at Risk Under Derivative Assets	1.00%

Derivatives Interest Rate Swa52

Derivatives Interest Rate Swap by Remaining Maturity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount of Derivatives	$ 200,000	$ 400,000
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Variable Interest Rate	1.91%	1.46%
Notional Amount of Derivatives	$ 3,630,000	$ 3,530,000	$ 2,975,000	$ 2,975,000
Derivative, Forward Interest Rate	1.64%	1.58%
Derivative, Average Fixed Interest Rate	1.68%	1.65%
Derivative, Average Remaining Maturity	4 years	4 years 2 months
Interest Rate Swap [Member] | Greater Than One Year and Less Than or Equal to Three Years [Member]
Derivative [Line Items]
Derivative, Variable Interest Rate	1.90%	1.46%
Notional Amount of Derivatives	$ 1,600,000	$ 1,500,000
Derivative, Average Fixed Interest Rate	1.31%	1.26%
Derivative, Average Remaining Maturity	1 year 2 months	1 year 4 months
Interest Rate Swap [Member] | Greater Than Three Years and Less Than or Equal to Five Years [Member]
Derivative [Line Items]
Derivative, Variable Interest Rate	1.94%	1.47%
Notional Amount of Derivatives	$ 935,000	$ 985,000
Derivative, Average Fixed Interest Rate	1.77%	1.79%
Derivative, Average Remaining Maturity	3 years 11 months	4 years
Interest Rate Swap [Member] | Greater Than Five Years and Less than or Equal to Seven Years [Member]
Derivative [Line Items]
Derivative, Variable Interest Rate	1.79%	1.40%
Notional Amount of Derivatives	$ 400,000	$ 350,000
Derivative, Average Fixed Interest Rate	1.98%	1.78%
Derivative, Average Remaining Maturity	5 years 5 months	5 years 8 months
Interest Rate Swap [Member] | Greater Than Seven Years [Member]
Derivative [Line Items]
Derivative, Variable Interest Rate	1.96%	1.47%
Notional Amount of Derivatives	$ 695,000	$ 695,000
Derivative, Average Fixed Interest Rate	2.26%	2.26%
Derivative, Average Remaining Maturity	9 years 7 months	9 years 11 months

Derivatives Interest Rate Swapt

Derivatives Interest Rate Swaptions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount of Interest Rate Derivatives	$ 200,000	$ 400,000
Interest Rate Swaption [Member]
Derivative [Line Items]
Options At Cost	12,915	12,145
Interest Rate Derivatives, at Fair Value, Net	$ 12,820	$ 6,728
Weighted Average Years to Swaption Maturity	1 year 8 months	2 years
Notional Amount of Interest Rate Derivatives	$ 500,000	$ 425,000	$ 150,000	$ 150,000
Interest Rate Derivative Not Designated As Hedging instruments Pay Rate	2.81%	2.78%
Derivatives Average Term	8 years 6 months	8 years 11 months
Greater Than 3 Months and Less Than 12 Months [Domain] | Interest Rate Swaption [Member]
Derivative [Line Items]
Options At Cost	$ 2,341	$ 2,111
Interest Rate Derivatives, at Fair Value, Net	$ 3,979	$ 1,621
Weighted Average Years to Swaption Maturity	8 months	11 months
Notional Amount of Interest Rate Derivatives	$ 200,000	$ 175,000
Interest Rate Derivative Not Designated As Hedging instruments Pay Rate	2.73%	2.71%
Derivatives Average Term	8 years 5 months	8 years 7 months
Greaterthan12Monthsandlessthanorequalto24Months [Member] | Interest Rate Swaption [Member]
Derivative [Line Items]
Options At Cost	$ 2,623	$ 2,083
Interest Rate Derivatives, at Fair Value, Net	$ 3,077	$ 1,400
Weighted Average Years to Swaption Maturity	1 year 2 months	1 year 6 months
Notional Amount of Interest Rate Derivatives	$ 125,000	$ 75,000
Interest Rate Derivative Not Designated As Hedging instruments Pay Rate	2.86%	2.73%
Derivatives Average Term	8 years 5 months	10 years
Greater Than 24 Months [Domain] | Interest Rate Swaption [Member]
Derivative [Line Items]
Options At Cost	$ 7,951	$ 7,951
Interest Rate Derivatives, at Fair Value, Net	$ 5,764	$ 3,707
Weighted Average Years to Swaption Maturity	3 years 2 months	3 years 5 months
Notional Amount of Interest Rate Derivatives	$ 175,000	$ 175,000
Interest Rate Derivative Not Designated As Hedging instruments Pay Rate	2.87%	2.87%
Derivatives Average Term	8 years 8 months	8 years 11 months

Derivatives TBA Securities (Det

Derivatives TBA Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional Amount of Derivatives	$ 200,000	$ 400,000
TBA securities Fifteen Year and Thirty Year Securities [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,586,844	1,704,386
Derivative, Fair Value, Net	9,711	1,751
Derivative Assets [Member] | TBA securities Fifteen Year and Thirty Year Securities [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,586,844	1,385,216
Derivative, Fair Value, Net	9,711	3,090
Derivative Assets [Member] | TBA securities Fifteen Year and Thirty Year Securities [Member] | Long [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,586,844	1,386,416
Derivative, Fair Value, Net	9,711	3,089
Derivative Assets [Member] | TBA securities Fifteen Year and Thirty Year Securities [Member] | Short [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	1,200
Derivative, Fair Value, Net	0	1
Derivative liabilities [Member] | TBA securities Fifteen Year and Thirty Year Securities [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	319,170
Derivative, Fair Value, Net	0	(1,339)
Derivative liabilities [Member] | TBA securities Fifteen Year and Thirty Year Securities [Member] | Long [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	319,170
Derivative, Fair Value, Net	0	(1,339)
Derivative liabilities [Member] | TBA securities Fifteen Year and Thirty Year Securities [Member] | Short [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	0
Derivative, Fair Value, Net	$ 0	$ 0

Derivatives U.S. Treasury Secur

Derivatives U.S. Treasury Securities and Futures (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Open Option Contracts Written [Line Items]
US Government Securities, at Carrying Value	$ 24,924	$ 0
Notional Amount of Derivatives	(200,000)	(400,000)
Derivative Liabilities	0	4,454
Derivative Asset	29,726	14,712
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	824,688	830,776
Receivable Under Reverse Repurchase Agreements	836,901	843,130
US Treasury Securities [Member]
Open Option Contracts Written [Line Items]
Notional Amount of Derivatives	$ (25,000)	$ 0	$ 0	$ (21,000)

Derivatives Credit Risk Conting

Derivatives Credit Risk Contingent Features (Details)	Mar. 31, 2018
Maximum [Member]
Derivative [Line Items]
Percent of Equity at Risk Under Derivative Assets	1.00%

Offsetting Assets and Liabili57

Offsetting Assets and Liabilities Offsetting of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Securities Sold under Agreements to Repurchase [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)	$ 836,901	$ 843,130
Gross Amounts Offset on the Balance Sheet	0	0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet	836,901	843,130
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet	(666,306)	(725,319)
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet	(170,595)	(117,811)
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet	0	0
Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)	866,627	857,842
Gross Amounts Offset on the Balance Sheet	0	0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet	866,627	857,842
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet	(666,306)	(726,658)
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet	(187,486)	(123,453)
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet	12,835	7,731
Repurchase Agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)	3,743,436	3,863,719
Gross Amounts Offset on the Balance Sheet	0	0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet	3,743,436	3,863,719
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet	(666,306)	(725,319)
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet	(3,077,130)	(3,138,400)
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet	0	0
Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)	3,743,436	3,865,058
Gross Amounts Offset on the Balance Sheet	0	0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet	3,743,436	3,865,058
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet	(666,306)	(726,658)
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet	(3,077,130)	(3,138,400)
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet	0	0
Interest Rate Contract [Member] | Derivative Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)	20,015	11,622
Gross Amounts Offset on the Balance Sheet	0	0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet	20,015	11,622
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet	0	0
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet	(16,891)	(5,642)
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet	3,124	5,980
Forward Contracts [Member] | Derivative Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)	9,711	3,090
Gross Amounts Offset on the Balance Sheet	0	0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet	9,711	3,090
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet	0	(1,339)
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet	0	0
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet	$ 9,711	1,751
Forward Contracts [Member] | Derivative liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Amount of Recognized Assets (Liabilities)		1,339
Gross Amounts Offset on the Balance Sheet		0
Net Amount of Assets (Liabilities) Presented on the Balance Sheet		1,339
Gross Amounts of Financial Instruments Not Offset on the Balance Sheet		(1,339)
Gross Amounts of Cash Collateral Not Offset on the Balance Sheet		0
Net Amount After Deducting Gross Amounts Not Offset on the Balance Sheet From Net Amount of Assets (Liabilities) Presented on the Balance Sheet		$ 0

Fair Value Measurements Financi

Fair Value Measurements Financial Instruments Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	$ 3,660,403	$ 3,758,181
Non-Agency Securities, at Fair Value	833,681	872,084
US Government Securities, at Carrying Value (including pledged securities of $24,903 and $0, respectively)	24,924	0
Derivative Asset	29,726	14,712
Derivative liabilities, at fair value	0	4,454
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	824,688	830,776
Fair Value, Measurements, Recurring [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	3,660,403	3,758,181
Non-Agency Security, at Fair Value	833,681
Non-Agency Securities, at Fair Value		872,084
US Government Securities, at Carrying Value (including pledged securities of $24,903 and $0, respectively)	24,924
Derivative Asset	29,726	14,712
Assets, Fair Value Disclosure, Recurring	4,548,734	4,644,977
Derivative liabilities, at fair value		4,454
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	824,688	830,776
Liabilities, Fair Value Disclosure, Recurring	824,688	835,230
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	0	0
Non-Agency Security, at Fair Value	0
Non-Agency Securities, at Fair Value		0
US Government Securities, at Carrying Value (including pledged securities of $24,903 and $0, respectively)	24,924
Derivative Asset	0	0
Assets, Fair Value Disclosure, Recurring	24,924	0
Derivative liabilities, at fair value		0
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	824,688	830,776
Liabilities, Fair Value Disclosure, Recurring	824,688	830,776
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	3,660,403	3,758,181
Non-Agency Security, at Fair Value	833,681
Non-Agency Securities, at Fair Value		872,084
US Government Securities, at Carrying Value (including pledged securities of $24,903 and $0, respectively)	0
Derivative Asset	29,726	14,712
Assets, Fair Value Disclosure, Recurring	4,523,810	4,644,977
Derivative liabilities, at fair value		4,454
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	0	0
Liabilities, Fair Value Disclosure, Recurring	0	4,454
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Agency securities, at fair value (including pledged securities of $3,434,631 and $3,581,868, respectively)	0	0
Non-Agency Security, at Fair Value	0
Non-Agency Securities, at Fair Value		0
US Government Securities, at Carrying Value (including pledged securities of $24,903 and $0, respectively)	0
Derivative Asset	0	0
Assets, Fair Value Disclosure, Recurring	0	0
Derivative liabilities, at fair value		0
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	0	0
Liabilities, Fair Value Disclosure, Recurring	$ 0	$ 0

Other Assets Schedule of Other

Other Assets Schedule of Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Other Assets [Line Items]
Goodwill	$ 5,840	$ 5,840
Other Receivables	0	324
Prepaid Expense, Current	1,595	1,993
Accounts and Notes Receivable, Net	2,033	5,682
Intangible Assets, Net (Including Goodwill)	5,840	5,840
Other Assets, Miscellaneous, Current	6,557	9,403
Other Assets	$ 16,025	$ 23,242

Other Liabilities Schedule of O

Other Liabilities Schedule of Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative, Collateral, Obligation to Return Cash	$ 16,992	$ 5,642
Due to Affiliate, Current	1,473	1,451
Interest Payable, Current	15,181	12,547
Other Accounts Payable and Accrued Liabilities	11,258	13,952
Accounts Payable and Accrued Liabilities	$ 44,904	$ 33,592

Stockholder's Equity Preferred

Stockholder's Equity Preferred Stock Offering (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	50,000	50,000
Preferred Stock, Shares Issued	2,200	2,200
Preferred Stock, Value, Issued	$ 53,039	$ 53,039
Preferred Class A [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	2,300
Preferred Stock, Dividend Rate, Percentage	8.125%
Preferred Stock, Shares Subscribed but Unissued	47,800
Preferred Stock, Redemption Price Per Share	$ 25

Stockholder's Equity Stock Repu

Stockholder's Equity Stock Repurchase Program (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 100
Stock Repurchase Program Expiration Date	Dec. 31, 2018
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 100

Stockholder's Equity Long Term

Stockholder's Equity Long Term Incentive Plan (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Class of Stock [Line Items]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	0
Share-based Compensation	$ 68	$ 34

Stockholder's Equity At-the-Mar

Stockholder's Equity At-the-Market Offering (Details) $ in Millions	Mar. 31, 2018USD ($)
At-the-Market Offering [Abstract]
Common stock, Value of Shares Approved for Future Issuance	$ 125

Uncategorized Items - mtge-2018

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 136,645,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 170,086,000