Blackstone Mortgage Trust (BXMT) 10-Q 24 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 17, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	BXMT
Entity Registrant Name	BLACKSTONE MORTGAGE TRUST, INC.
Entity Central Index Key	1,061,630
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		94,828,437

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 61,221	$ 75,567
Restricted cash	32,864
Loans receivable, net	9,637,152	8,692,978
Other assets	45,680	44,070
Total Assets	9,776,917	8,812,615
Liabilities and Equity
Secured debt agreements, net	6,079,135	5,716,354
Loan participations sold, net	33,193	348,077
Securitized debt obligations, net	474,298	0
Convertible notes, net	562,741	166,762
Other liabilities	101,758	87,819
Total Liabilities	7,251,125	6,319,012
Commitments and contingencies
Equity
Class A common stock, $0.01 par value, 200,000,000 shares authorized, 94,828,007 and 94,540,263 shares issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	948	945
Additional paid-incapital	3,109,094	3,089,997
Accumulated other comprehensive loss	(32,362)	(56,202)
Accumulated deficit	(558,066)	(541,137)
Total Blackstone Mortgage Trust, Inc. stockholders' equity	2,519,614	2,493,603
Non-controllinginterests	6,178
Total Equity	2,525,792	2,493,603
Total Liabilities and Equity	$ 9,776,917	$ 8,812,615

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value in dollars per share	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	94,828,007	94,540,263
Common stock, shares outstanding	94,828,007	94,540,263
Variable interest entity, consolidated, carrying amount, assets	$ 500.8
Variable interest entity, consolidated, carrying amount, liabilities	$ 474.9

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income from loans and other investments
Interest and related income	$ 146,446	$ 128,190	$ 391,787	$ 381,686
Less: Interest and related expenses	67,891	45,373	168,917	139,819
Income from loans and other investments, net	78,555	82,817	222,870	241,867
Other expenses
Management and incentive fees	13,243	13,701	40,557	43,161
General and administrative expenses	7,419	7,414	22,219	20,990
Total other expenses	20,662	21,115	62,776	64,151
Gain on investments at fair value		2,824		13,413
Income from equity investment in unconsolidated subsidiary		2,060		2,192
Income before income taxes	57,893	66,586	160,094	193,321
Income tax provision	83	194	265	281
Net income	57,810	66,392	159,829	193,040
Net income attributable to non-controlling interests	(88)	(1,598)	(88)	(8,119)
Net income attributable to Blackstone Mortgage Trust, Inc.	$ 57,722	$ 64,794	$ 159,741	$ 184,921
Net income per share of common stock basic and diluted	$ 0.61	$ 0.69	$ 1.68	$ 1.97
Weighted-average shares of common stock outstanding, basic and diluted	95,013,087	94,071,537	95,004,188	94,067,923
Dividends declared per share of common stock	$ 0.62	$ 0.62	$ 1.86	$ 1.86

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net income	$ 57,810	$ 66,392	$ 159,829	$ 193,040
Other comprehensive income
Unrealized gain (loss) on foreign currency remeasurement	16,175	(10,128)	43,990	(25,472)
Realized and unrealized (loss) gain on derivative financial instruments	(8,029)	5,882	(20,150)	11,841
Other comprehensive income (loss)	8,146	(4,246)	23,840	(13,631)
Comprehensive income	65,956	62,146	183,669	179,409
Comprehensive income attributable to non-controlling interests	(88)	(1,598)	(88)	(8,119)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 65,868	$ 60,548	$ 183,581	$ 171,290

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Class A Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]	Stockholders' Equity [Member]	Non-controlling Interests [Member]
Balance at Dec. 31, 2015	$ 2,505,731	$ 937	$ 3,070,200	$ (32,758)	$ (545,791)	$ 2,492,588	$ 13,143
Shares of class A common stock issued, net	2	2				2
Restricted class A common stock earned	14,190		14,190			14,190
Dividends reinvested	20		276		(256)	20
Deferred directors' compensation	282		282			282
Other comprehensive income (loss)	(13,631)			(13,631)		(13,631)
Net income	193,040				184,921	184,921	8,119
Dividends declared on common stock	(174,678)				(174,678)	(174,678)
Distributions to non-controlling interests	(20,158)						(20,158)
Balance at Sep. 30, 2016	2,504,798	939	3,084,948	(46,389)	(535,804)	2,503,694	1,104
Balance at Dec. 31, 2016	2,493,603	945	3,089,997	(56,202)	(541,137)	2,493,603
Shares of class A common stock issued, net	3	3				3
Restricted class A common stock earned	17,493		17,493			17,493
Issuance of convertible notes	964		964			964
Dividends reinvested	31		327		(296)	31
Deferred directors' compensation	313		313			313
Other comprehensive income (loss)	23,840			23,840		23,840
Net income	159,829				159,741	159,741	88
Contributions from non-controlling interests	6,090						6,090
Dividends declared on common stock	(176,374)				(176,374)	(176,374)
Balance at Sep. 30, 2017	$ 2,525,792	$ 948	$ 3,109,094	$ (32,362)	$ (558,066)	$ 2,519,614	$ 6,178

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income	$ 159,829	$ 193,040
Adjustments to reconcile net income to net cash provided by operating activities
Non-cash compensation expense	17,809	16,517
Amortization of deferred fees on loans	(28,887)	(31,594)
Amortization of deferred financing costs and premiums/discount on debt obligations	16,356	15,129
Income from equity investment in unconsolidated subsidiary		(2,192)
Distributions of income from unconsolidated subsidiary		8,167
Gain on investments at fair value		(13,413)
Changes in assets and liabilities, net
Other assets	(219)	8,315
Other liabilities	11,651	(6,405)
Net cash provided by operating activities	176,539	187,564
Cash flows from investing activities
Origination and fundings of loans receivable	(2,314,721)	(2,300,636)
Principal collections and sales proceeds from loans receivable and other assets	1,976,271	3,054,821
Origination and exit fees received on loans receivable	38,434	35,388
Receipts under derivative financial instruments	6,115
Payments under derivative financial instruments	(18,115)
Return of collateral deposited under derivative agreements	8,980
Collateral deposited under derivative agreements	(16,651)
Net cash (used in) provided by investing activities	(319,687)	789,573
Cash flows from financing activities
Borrowings under secured debt agreements	2,776,058	2,225,895
Repayments under secured debt agreements	(2,481,250)	(2,988,217)
Proceeds from sale of loan participations	33,193	54,441
Repayment of loan participations	(381,310)	(92,000)
Payment of deferred financing costs	(13,591)	(12,564)
Receipts under derivative financial instruments		31,668
Payments under derivative financial instruments		(14,266)
Contributions from non-controlling interests	6,090
Distributions to non-controlling interests		(20,158)
Net proceeds from issuance of convertible notes	394,074
Net proceeds from issuance of class A common stock	31	20
Dividends paid on class A common stock	(176,195)	(174,549)
Net cash provided by (used in) financing activities	157,100	(989,730)
Net increase (decrease) in cash, cash equivalents, and restricted cash	13,952	(12,593)
Cash, cash equivalents, and restricted cash at beginning of period	75,567	106,005
Effects of currency translation on cash, cash equivalents, and restricted cash	4,566	1,526
Cash, cash equivalents, and restricted cash at end of period	94,085	94,938
Supplemental disclosure of cash flows information
Payments of interest	(141,124)	(123,564)
Payments of income taxes	(220)	(131)
Supplemental disclosure of non-cash investing and financing activities
Dividends declared, not paid	(58,793)	(58,388)
Loan principal payments held by servicer, net	513	$ 9,515
Consolidation of loans receivable of a VIE	500,000
Consolidation of securitized debt obligations of a VIE	$ (474,620)

Organization

Organization	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. ORGANIZATION References herein to “Blackstone Mortgage Trust,” “Company,” “we,” “us” or “our” refer to Blackstone Mortgage Trust, Inc. and its subsidiaries unless the context specifically requires otherwise. Blackstone Mortgage Trust is a real estate finance company that originates and purchases senior loans collateralized by properties in North America and Europe. We are externally managed by BXMT Advisors L.L.C., or our Manager, a subsidiary of The Blackstone Group L.P., or Blackstone, and are a real estate investment trust, or REIT, traded on the New York Stock Exchange, or NYSE, under the symbol “BXMT.” We are headquartered in New York City. We conduct our operations as a REIT for U.S. federal income tax purposes. We generally will not be subject to U.S. federal income taxes on our taxable income to the extent that we annually distribute all of our net taxable income to stockholders and maintain our qualification as a REIT. We also operate our business in a manner that permits us to maintain an exclusion from registration under the Investment Company Act of 1940, as amended. We are organized as a holding company and conduct our business primarily through our various subsidiaries.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, for interim financial information and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. The consolidated financial statements, including the notes thereto, are unaudited and exclude some of the disclosures required in annual financial statements. Management believes it has made all necessary adjustments, consisting of only normal recurring items, so that the consolidated financial statements are presented fairly and that estimates made in preparing its consolidated financial statements are reasonable and prudent. The operating results presented for interim periods are not necessarily indicative of the results that may be expected for any other interim period or for the entire year. The accompanying unaudited consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2016 filed with the Securities and Exchange Commission, or the SEC. Basis of Presentation The accompanying consolidated financial statements include, on a consolidated basis, our accounts, the accounts of our wholly-owned subsidiaries, majority-owned subsidiaries, and variable interest entities, or VIEs, of which we are the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation. Principles of Consolidation We consolidate all entities that we control through either majority ownership or voting rights. In addition, we consolidate all VIEs of which we are considered the primary beneficiary. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest and/or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary and is generally the entity with (i) the power to direct the activities that most significantly affect the VIE’s economic performance and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. Refer to Note 16 for additional discussion of our consolidated VIE. In April 2017, we entered into a joint venture, or our Multifamily Joint Venture, with Walker & Dunlop Inc. to originate, hold, and finance multifamily bridge loans. Pursuant to the terms of the agreements governing the joint venture, Walker & Dunlop contributed 15% of the venture’s equity capital and we contributed 85%. We consolidate the Multifamily Joint Venture as we have a controlling financial interest. The non-controlling interests included on our consolidated balance sheets represent the equity interests in our Multifamily Joint Venture that are owned by Walker & Dunlop. A portion of our Multifamily Joint Venture’s consolidated equity and results of operations are allocated to these non-controlling interests based on Walker & Dunlop’s pro-rata ownership of our Multifamily Joint Venture. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results may ultimately differ from those estimates. Revenue Recognition Interest income from our loans receivable portfolio is recognized over the life of each investment using the effective interest method and is recorded on the accrual basis. Recognition of fees, premiums, and discounts associated with these investments is deferred until the loan is advanced and is then recorded over the term of the loan as an adjustment to yield. Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful. Income is then recorded on the basis of cash received until accrual is resumed when the loan becomes contractually current and performance is demonstrated to be resumed. In addition, for loans we originate, the related origination expenses are deferred and recognized as a component of interest income; however, expenses related to loans we acquire are included in general and administrative expenses as incurred. Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents represent cash held in banks, cash on hand, and liquid investments with original maturities of three months or less. We may have bank balances in excess of federally insured amounts; however, we deposit our cash and cash equivalents with high credit-quality institutions to minimize credit risk exposure. We have not experienced, and do not expect, any losses on our cash or cash equivalents. Restricted cash represents cash held in a segregated bank account related to a letter of credit. The following table provides a reconciliation of cash, cash equivalents, and restricted cash in our consolidated balance sheets to the total amount shown in our consolidated statements of cash flows ($ in thousands): September 30, 2017 September 30, 2016 Cash and cash equivalents $ 61,221 $ 94,061 Restricted cash 32,864 877 Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows $ 94,085 $ 94,938 Loans Receivable and Provision for Loan Losses We originate and purchase commercial real estate debt and related instruments generally to be held as long-term investments at amortized cost. We are required to periodically evaluate each of these loans for possible impairment. Impairment is indicated when it is deemed probable that we will not be able to collect all amounts due to us pursuant to the contractual terms of the loan. If a loan is determined to be impaired, we write down the loan through a charge to the provision for loan losses. Impairment of these loans, which are collateral dependent, is measured by comparing the estimated fair value of the underlying collateral, less costs to sell, to the book value of the respective loan. These valuations require significant judgments, which include assumptions regarding capitalization rates, leasing, creditworthiness of major tenants, occupancy rates, availability of financing, exit plan, loan sponsorship, actions of other lenders, and other factors deemed necessary by our Manager. Actual losses, if any, could ultimately differ from these estimates. Our Manager performs a quarterly review of our portfolio of loans. In conjunction with this review, our Manager assesses the risk factors of each loan, and assigns a risk rating based on a variety of factors, including, without limitation, loan-to-value ratio, or LTV, debt yield, property type, geographic and local market dynamics, physical condition, cash flow volatility, leasing and tenant profile, loan structure and exit plan, and project sponsorship. Based on a 5-point scale, our loans are rated “1” through “5,” from less risk to greater risk, which ratings are defined as follows: 1 - Very Low Risk 2 - Low Risk 3 - Medium Risk 4 - High Risk/Potential for Loss: 5 - Impaired/Loss Likely: During the second quarter of 2015, we acquired a portfolio of loans from General Electric Capital Corporation and certain of its affiliates, or the GE portfolio, for a total purchase price of $4.7 billion. We allocated the aggregate purchase price between each loan based on its fair value relative to the overall portfolio, which allocation resulted in purchase discounts or premiums determined on an asset-by-asset basis. Each loan accretes from its allocated purchase price to its expected collection value over the life of the loan, consistent with the other loans in our portfolio. Equity Investment in Unconsolidated Subsidiary Our carried interest in CT Opportunity Partners I, LP, or CTOPI, was accounted for using the equity method. CTOPI’s assets and liabilities were not consolidated into our financial statements due to our determination that (i) it was not a VIE and (ii) the other investors in CTOPI had sufficient rights to preclude consolidation by us. As such, we reported our allocable percentage of the net assets of CTOPI on our consolidated balance sheets. The investment was fully realized as of December 31, 2016 and we no longer have any equity investments in unconsolidated subsidiaries in our consolidated financial statements. Derivative Financial Instruments We classify all derivative financial instruments as either other assets or other liabilities on our consolidated balance sheets at fair value. On the date we enter into a derivative contract, we designate each contract as (i) a hedge of a net investment in a foreign operation, or net investment hedge, (ii) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability, or cash flow hedge, (iii) a hedge of a recognized asset or liability, or fair value hedge, or (iv) a derivative instrument not to be designated as a hedging derivative, or non-designated hedge. For all derivatives other than those designated as non-designated hedges, we formally document our hedge relationships and designation at the contract’s inception. This documentation includes the identification of the hedging instruments and the hedged items, its risk management objectives, strategy for undertaking the hedge transaction and our evaluation of the effectiveness of its hedged transaction. On a quarterly basis, we also formally assess whether the derivative we designated in each hedging relationship is expected to be, and has been, highly effective in offsetting changes in the value or cash flows of the hedged items. If it is determined that a derivative is not highly effective at hedging the designated exposure, hedge accounting is discontinued and the changes in fair value of the instrument are included in net income prospectively. Changes in the fair value of our derivative instruments that qualify as hedges are reported as a component of accumulated other comprehensive income (loss) on our consolidated financial statements. Deferred gains and losses are reclassified out of accumulated other comprehensive income (loss) and into net income in the same period or periods during which the hedged transaction affects earnings, and are presented in the same line item as the earnings effect of the hedged item. For cash flow hedges, this is typically when the periodic swap settlements are made, while for net investment hedges, this occurs when the hedged item is sold or substantially liquidated. To the extent a derivative does not qualify for hedge accounting and is deemed a non-designated hedge, the changes in its fair value are included in net income concurrently. Secured Debt Agreements Where applicable, we record investments financed with repurchase agreements as separate assets and the related borrowings under any repurchase agreements are recorded as separate liabilities on our consolidated balance sheets. Interest income earned on the investments and interest expense incurred on the repurchase agreements are reported separately on our consolidated statements of operations. Senior Loan Participations In certain instances, we finance our loans through the non-recourse syndication of a senior loan interest to a third-party. Depending on the particular structure of the syndication, the senior loan interest may remain on our GAAP balance sheet or, in other cases, the sale will be recognized and the senior loan interest will no longer be included in our consolidated financial statements. When these sales are not recognized under GAAP we reflect the transaction by recording a loan participations sold liability on our consolidated balance sheet, however this gross presentation does not impact stockholders’ equity or net income. When the sales are recognized, our balance sheet only includes our remaining subordinate loan and not the non-consolidated senior interest we sold. Convertible Notes The “Debt with Conversion and Other Options” Topic of the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, requires the liability and equity components of convertible debt instruments that may be settled in cash upon conversion, including partial cash settlement, to be separately accounted for in a manner that reflects the issuer’s nonconvertible debt borrowing rate. The initial proceeds from the sale of convertible notes are allocated between a liability component and an equity component in a manner that reflects interest expense at the rate of similar nonconvertible debt that could have been issued at such time. The equity component represents the excess initial proceeds received over the fair value of the liability component of the notes as of the date of issuance. We measured the estimated fair value of the debt component of our convertible notes as of the respective issuance dates based on our nonconvertible debt borrowing rate. The equity component of each series of our convertible notes is reflected within additional paid-in capital on our consolidated balance sheet, and the resulting debt discount is amortized over the period during which such convertible notes are expected to be outstanding (through the maturity date) as additional non-cash interest expense. The additional non-cash interest expense attributable to such convertible notes will increase in subsequent periods through the maturity date as the notes accrete to their par value over the same period. Deferred Financing Costs The deferred financing costs that are included as a reduction in the net book value of the related liability on our consolidated balance sheets include issuance and other costs related to our debt obligations. These costs are amortized as interest expense using the effective interest method over the life of the related obligations. Fair Value of Financial Instruments The “Fair Value Measurements and Disclosures” Topic, or ASC 820, defines fair value, establishes a framework for measuring fair value, and requires certain disclosures about fair value measurements under GAAP. Specifically, this guidance defines fair value based on exit price, or the price that would be received upon the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date. ASC 820 also establishes a fair value hierarchy that prioritizes and ranks the level of market price observability used in measuring financial instruments. Market price observability is affected by a number of factors, including the type of financial instrument, the characteristics specific to the financial instrument, and the state of the marketplace, including the existence and transparency of transactions between market participants. Financial instruments with readily available quoted prices in active markets generally will have a higher degree of market price observability and a lesser degree of judgment used in measuring fair value. Financial instruments measured and reported at fair value are classified and disclosed based on the observability of inputs used in the determination, as follows: • Level 1: Generally includes only unadjusted quoted prices that are available in active markets for identical financial instruments as of the reporting date. • Level 2: Pricing inputs include quoted prices in active markets for similar instruments, quoted prices in less active or inactive markets for identical or similar instruments where multiple price quotes can be obtained, and other observable inputs, such as interest rates, yield curves, credit risks, and default rates. • Level 3: Pricing inputs are unobservable for the financial instruments and include situations where there is little, if any, market activity for the financial instrument. These inputs require significant judgment or estimation by management of third-parties when determining fair value and generally represent anything that does not meet the criteria of Levels 1 and 2. The estimated value of each asset reported at fair value using Level 3 inputs is determined by an internal committee composed of members of senior management of our Manager, including our Chief Executive Officer, Chief Financial Officer, and other senior officers. Certain of our other assets are reported at fair value either (i) on a recurring basis, as of each quarter-end, or (ii) on a nonrecurring basis, as a result of impairment or other events. Our assets that are recorded at fair value are discussed further in Note 15. We generally value our assets recorded at fair value by either (i) discounting expected cash flows based on assumptions regarding the collection of principal and interest and estimated market rates, or (ii) obtaining assessments from third-party dealers. For collateral-dependent loans that are identified as impaired, we measure impairment by comparing our Manager’s estimation of the fair value of the underlying collateral, less costs to sell, to the book value of the respective loan. These valuations may require significant judgments, which include assumptions regarding capitalization rates, leasing, creditworthiness of major tenants, occupancy rates, availability of financing, exit plan, loan sponsorship, actions of other lenders, and other factors deemed necessary by our Manager. We are also required by GAAP to disclose fair value information about financial instruments, that are not otherwise reported at fair value in our consolidated balance sheet, to the extent it is practicable to estimate a fair value for those instruments. These disclosure requirements exclude certain financial instruments and all non-financial instruments. The following methods and assumptions are used to estimate the fair value of each class of financial instruments, for which it is practicable to estimate that value: • Cash and cash equivalents: The carrying amount of cash and cash equivalents approximates fair value. • Restricted cash: The carrying amount of restricted cash approximates fair value. • Loans receivable, net: The fair values of these loans were estimated by our Manager based on a discounted cash flow methodology, taking into consideration various factors including capitalization rates, discount rates, leasing, occupancy rates, availability and cost of financing, exit plan, sponsorship, actions of other lenders, and indications of market value from other market participants. • Derivative financial instruments: The fair value of our foreign currency and interest rate contracts was estimated using advice from a third-party derivative specialist, based on contractual cash flows and observable inputs comprising foreign currency rates and credit spreads. • Secured debt agreements, net: The fair value of these instruments was estimated based on the rate at which a similar credit facility would currently be priced. • Loan participations sold, net: The fair value of these instruments was estimated based on the value of the related loan receivable asset. • Securitized debt obligations, net: The fair value of these instruments was estimated by utilizing third-party pricing service providers. In determining the value of a particular investment, pricing service providers may use broker-dealer quotations, reported trades, or valuation estimates from their internal pricing models to determine the reported price. • Convertible notes, net: Each series of the convertible notes is actively traded and their fair values were obtained using quoted market prices. Income Taxes Our financial results generally do not reflect provisions for current or deferred income taxes on our REIT taxable income. We believe that we operate in a manner that will continue to allow us to be taxed as a REIT and, as a result, we generally do not expect to pay substantial corporate level taxes other than those payable by our taxable REIT subsidiaries. If we were to fail to meet these requirements, we may be subject to federal, state, and local income tax on current and past income, and penalties. Refer to Note 13 for additional information. Stock-Based Compensation Our stock-based compensation consists of awards issued to our Manager and certain individuals employed by an affiliate of our Manager that vest over the life of the awards, as well as deferred stock units issued to certain members of our Board of Directors. Stock-based compensation expense is recognized for these awards in net income on a variable basis over the applicable vesting period of the awards, based on the value of our class A common stock. Refer to Note 14 for additional information. Earnings per Share Basic earnings per share, or Basic EPS, is computed in accordance with the two-class method and is based on the net earnings allocable to our class A common stock, including restricted class A common stock and deferred stock units, divided by the weighted-average number of shares of our class A common stock, including restricted class A common stock and deferred stock units outstanding during the period. Our restricted class A common stock is considered a participating security, as defined by GAAP, and has been included in our Basic EPS under the two-class method as these restricted shares have the same rights as our other shares of class A common stock, including participating in any gains or losses. Diluted earnings per share, or Diluted EPS, is determined using the treasury stock method, and is based on the net earnings allocable to our class A common stock, including restricted class A common stock and deferred stock units, divided by the weighted-average number of shares of our class A common stock, including restricted class A common stock and deferred stock units. Refer to Note 11 for additional discussion of earnings per share. Foreign Currency In the normal course of business, we enter into transactions not denominated in United States, or U.S., dollars. Foreign exchange gains and losses arising on such transactions are recorded as a gain or loss in our consolidated statements of operations. In addition, we consolidate entities that have a non-U.S. dollar functional currency. Non-U.S. dollar denominated assets and liabilities are translated to U.S. dollars at the exchange rate prevailing at the reporting date and income, expenses, gains, and losses are translated at the average exchange rate over the applicable period. Cumulative translation adjustments arising from the translation of non-U.S. dollar denominated subsidiaries are recorded in other comprehensive income (loss). Underwriting Commissions and Offering Costs Underwriting commissions and offering costs incurred in connection with common stock offerings are reflected as a reduction of additional paid-in capital. Costs incurred that are not directly associated with the completion of a common stock offering are expensed when incurred. Recent Accounting Pronouncements In August 2017, the FASB issued ASU 2017-12 “Derivatives and Hedging Topic 815: Targeted Improvements to Accounting for Hedging Activities,” or ASU 2017-12. ASU 2017-12 is intended to better align an entity’s financial reporting for hedging activities with the economic objectives of those activities. Upon adoption of ASU 2017-12, the cumulative ineffectiveness that has previously been recognized on existing cash flow and net investment hedges will be adjusted and removed from beginning retained earnings and placed in accumulated other comprehensive income (loss). We adopted ASU 2017-12 in the third quarter of 2017, which did not have an impact on our financial statements as we had not previously recognized any hedge ineffectiveness related to our existing cash flow and net investment hedges. In future periods, for hedges that are deemed effective, we will no longer need to bifurcate hedges into an effective and ineffective portion, and all gains or losses on effective hedges will be recognized in other comprehensive income (loss). In November 2016, the FASB issued ASU 2016-18 “Statement of Cash Flows (Topic 230): Restricted Cash,” or ASU 2016-18. ASU 2016-18 is intended to clarify how entities present restricted cash in the statement of cash flows. The guidance requires entities to show the changes in the total of cash and cash equivalents and restricted cash in the statement of cash flows. As a result, entities will no longer present transfers between cash and cash equivalents and restricted cash in the statement of cash flows. We adopted ASU 2016-18 in the second quarter of 2017 and applied the guidance retrospectively to our prior period consolidated statement of cash flows. In June 2016, the FASB issued ASU 2016-13 “Financial Instruments – Credit Losses – Measurement of Credit Losses on Financial Instruments (Topic 326),” or ASU 2016-13. ASU 2016-13 significantly changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. ASU 2016-13 will replace the “incurred loss” model under existing guidance with an “expected loss” model for instruments measured at amortized cost, and require entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do today under the other-than-temporary impairment model. It also simplifies the accounting model for purchased credit-impaired debt securities and loans. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019 and is to be adopted through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. While we are currently evaluating the impact ASU 2016-13 will have on our consolidated financial statements, we expect that the adoption will result in an increased amount of provisions for potential loan losses as well as the recognition of such provisions earlier in the lending cycle. We currently do not have any provision for loan losses on our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606) ,

Loans Receivable, Net

Loans Receivable, Net	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Loans Receivable, Net	3. LOANS RECEIVABLE, NET The following table details overall statistics for our loans receivable portfolio ($ in thousands): September 30, 2017 December 31, 2016 Number of loans 111 107 Principal balance $ 9,681,055 $ 8,727,218 Net book value $ 9,637,152 $ 8,692,978 Unfunded loan commitments (1) $ 1,622,216 $ 882,472 Weighted-average cash coupon (2) 5.30 % 5.01 % Weighted-average all-in yield (2) 5.68 % 5.36 % Weighted-average maximum maturity (years) (3) 3.4 3.2 (1) Unfunded commitments will primarily be funded to finance property improvements or lease-related expenditures by the borrowers. These future commitments will be funded over the term of each loan, subject in certain cases to an expiration date. (2) As of September 30, 2017, our floating rate loans were indexed to various benchmark rates, with 91% of floating rate loans by principal balance indexed to USD LIBOR. In addition, $273.9 million of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 1.24%, as of September 30, 2017. As of December 31, 2016, our floating rate loans were indexed to various benchmark rates, with 84% of floating rate loans indexed to USD LIBOR. In addition, $216.3 million of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 1.27%, as of December 31, 2016. In addition to cash coupon, all-in yield includes the amortization of deferred origination and extension fees, loan origination costs, purchase discounts, and accrual of exit fees. Cash coupon and all-in yield assume applicable floating benchmark rates for weighted-average calculation. (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of September 30, 2017, 72% of our loans by principal balance were subject to yield maintenance or other prepayment restrictions and 28% were open to repayment by the borrower without penalty. As of December 31, 2016, 64% of our loans were subject to yield maintenance or other prepayment restrictions and 36% were open to repayment by the borrower without penalty. Activity relating to our loans receivable portfolio was as follows ($ in thousands): Principal Deferred Fees / (1) Net Book Value December 31, 2016 $ 8,727,218 $ (34,240) $ 8,692,978 Loan fundings 2,789,341 — 2,789,341 Loan repayments (1,970,743 ) — (1,970,743 ) Unrealized gain (loss) on foreign currency translation 135,239 (116 ) 135,123 Deferred fees and other items — (38,434 ) (38,434 ) Amortization of fees and other items — 28,887 28,887 September 30, 2017 $ 9,681,055 $ (43,903 ) $ 9,637,152 (1) Other items primarily consist of purchase discounts or premiums, exit fees, and deferred origination expenses. The tables below detail the property type and geographic distribution of the properties securing the loans in our portfolio ($ in thousands): September 30, 2017 Property Type Number of Net Book Total Loan (1) Percentage of Office 55 $ 5,781,675 $ 5,814,214 54% Hotel 14 1,713,162 1,784,893 17 Retail 7 539,752 982,270 9 Multifamily 17 762,969 767,875 7 Condominium 2 129,421 273,112 3 Manufactured housing 7 232,148 231,856 2 Other 9 478,025 814,457 8 111 $ 9,637,152 $ 10,668,677 100% Geographic Location Number of Net Book Total Loan (1) Percentage of United States Northeast 26 $ 2,680,546 $ 2,694,018 25% West 28 2,470,097 2,629,456 24 Southeast 21 1,964,534 2,414,994 23 Midwest 8 890,546 894,564 8 Southwest 8 291,792 290,393 3 Northwest 2 249,118 251,422 2 Subtotal 93 8,546,633 9,174,847 85 International United Kingdom 7 486,794 838,763 8 Canada 7 462,832 458,619 4 Belgium 1 72,544 73,247 1 Germany 1 12,114 66,810 1 Netherlands 2 56,235 56,391 1 Subtotal 18 1,090,519 1,493,830 15 Total 111 $ 9,637,152 $ 10,668,677 100% (1) In certain instances, we finance our loans through the non-recourse sale of a senior loan interest that is not included in our consolidated financial statements. See Note 2 for further discussion. Total loan exposure encompasses the entire loan we originated and financed, including $987.6 million of such non-consolidated senior interests as of September 30, 2017. December 31, 2016 Property Type Number of Net Book Total Loan (1) Percentage of Office 55 $ 4,800,609 $ 4,889,456 50% Hotel 18 1,889,732 1,957,334 20 Retail 9 769,813 1,173,592 12 Multifamily 8 521,097 523,529 5 Manufactured housing 9 296,290 296,252 3 Condominium 2 66,070 258,360 3 Other 6 349,367 658,211 7 107 $ 8,692,978 $ 9,756,734 100% Geographic Location Number of Net Book Total Loan (1) Percentage of United States Northeast 26 $ 2,548,257 $ 2,562,149 26% Southeast 21 1,492,530 1,899,748 19 West 22 1,628,811 1,828,667 19 Midwest 7 695,713 698,093 7 Southwest 8 380,639 379,766 4 Northwest 3 227,747 293,564 3 Subtotal 87 6,973,697 7,661,987 78 International United Kingdom 9 977,136 1,305,816 13 Canada 8 487,835 483,923 5 Germany 1 204,241 254,644 3 Netherlands 2 50,069 50,364 1 Subtotal 20 1,719,281 2,094,747 22 Total 107 $ 8,692,978 $ 9,756,734 100% (1) In certain instances, we finance our loans through the non-recourse sale of a senior loan interest that is not included in our consolidated financial statements. See Note 2 for further discussion. Total loan exposure encompasses the entire loan we originated and financed, including $1.0 billion of such non-consolidated senior interests as of December 31, 2016. Loan Risk Ratings As further described in Note 2, our Manager evaluates our loan portfolio on a quarterly basis. In conjunction with our quarterly loan portfolio review, our Manager assesses the risk factors of each loan, and assigns a risk rating based on several factors. Factors considered in the assessment include, but are not limited to, risk of loss, current LTV, debt yield, collateral performance, structure, exit plan, and sponsorship. Loans are rated “1” (less risk) through “5” (greater risk), which ratings are defined in Note 2. The following table allocates the principal balance and net book value of our loans receivable based on our internal risk ratings ($ in thousands): September 30, 2017 December 31, 2016 Risk Rating Number of Loans Net Book Value Total Loan Exposure (1) Risk Rating Number of Loans Net Book Value Total Loan Exposure (1) 1 4 $ 421,313 $ 421,628 1 8 $ 361,100 $ 361,574 2 49 3,701,801 3,708,603 2 52 4,011,992 4,083,678 3 57 5,493,409 6,517,829 3 46 4,299,026 5,290,668 4 1 20,629 20,617 4 1 20,860 20,814 5 — — — 5 — — — 111 $ 9,637,152 $ 10,668,677 107 $ 8,692,978 $ 9,756,734 (1) In certain instances, we finance our loans through the non-recourse sale of a senior loan interest that is not included in our consolidated financial statements. See Note 2 for further discussion. Total loan exposure encompasses the entire loan we originated and financed, including $987.6 million and $1.0 billion of such non-consolidated senior interests as of September 30, 2017 and December 31, 2016, respectively. The weighted-average risk rating of our total loan exposure was 2.6 and 2.5 as of September 30, 2017 and December 31, 2016, respectively. The increase in weighted-average risk rating was primarily driven by repayments of loans with lower risk ratings, and not rating downgrades in the existing portfolio. We did not have any impaired loans, nonaccrual loans, or loans in maturity default as of September 30, 2017 or December 31, 2016. Multifamily Joint Venture As discussed in Note 2, we entered into a Multifamily Joint Venture in April 2017. As of September 30, 2017, our Multifamily Joint Venture held $146.1 million of loans, which are included in the loan disclosures above. Refer to Note 2 for additional discussion of our Multifamily Joint Venture.

Equity Investment in Unconsolid

Equity Investment in Unconsolidated Subsidiary	9 Months Ended
	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment in Unconsolidated Subsidiary	4. EQUITY INVESTMENT IN UNCONSOLIDATED SUBSIDIARY Our equity investment in unconsolidated subsidiary consisted solely of our carried interest in CTOPI, a fund formerly sponsored and managed by an affiliate of our Manager. The investment was fully realized as of December 31, 2016 and we no longer have any investments in unconsolidated subsidiaries on our consolidated financial statements. Our carried interest in CTOPI entitled us to earn promote revenue in an amount equal to 17.7% of the fund’s profits, after a 9% preferred return and 100% return of capital to the CTOPI partners. We recognized $2.1 million and $2.2 million of promote income from CTOPI in respect of our carried interest and recorded such amounts in our consolidated statements of operations during the three and nine months ended September 30, 2016, respectively. CTOPI Incentive Management Fee Grants In January 2011, we created a management compensation pool for employees equal to 45% of the CTOPI promote distributions received by us. During the nine months ended September 30, 2016, we recognized $1.1 million of expenses under the CTOPI incentive plan. Such amounts were recognized as a component of general and administrative expenses in our consolidated statement of operations.

Other Assets and Liabilities

Other Assets and Liabilities	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Other Assets and Liabilities	5. OTHER ASSETS AND LIABILITIES The following table details the components of our other assets ($ in thousands): September 30, 2017 December 31, 2016 Accrued interest receivable $ 34,715 $ 32,871 Collateral deposited under derivative agreements 7,750 79 Derivative assets 1,628 4,086 Loan portfolio payments held by servicer (1) 845 5,765 Prepaid expenses 469 803 Prepaid taxes 34 16 Other 239 450 Total $ 45,680 $ 44,070 (1) Represents loan principal and interest payments held by our third-party loan servicer as of the balance sheet date which were remitted to us during the subsequent remittance cycle. The following table details the components of our other liabilities ($ in thousands): September 30, 2017 December 31, 2016 Accrued dividends payable $ 58,793 $ 58,615 Accrued interest payable 19,922 9,049 Accrued management and incentive fees payable 13,243 12,798 Derivative liabilities 7,167 210 Accounts payable and other liabilities 2,633 1,775 Secured debt repayments pending servicer remittance (1) — 5,372 Total $ 101,758 $ 87,819 (1) Represents pending transfers from our third-party loan servicer that were remitted to our banking counterparties during the subsequent remittance cycle.

Secured Debt Agreements, Net

Secured Debt Agreements, Net	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Secured Debt Agreements, Net	6. SECURED DEBT AGREEMENTS, NET Our secured debt agreements include credit facilities, the GE portfolio acquisition facility, asset-specific financings, and a revolving credit agreement. The following table details our secured debt agreements ($ in thousands): Secured Debt Agreements Borrowings Outstanding September 30, 2017 December 31, 2016 Credit facilities $ 4,386,645 $ 3,572,837 GE portfolio acquisition facility 1,090,946 1,479,582 Asset-specific financings 517,256 679,207 Revolving credit agreement 101,750 — Total secured debt agreements $ 6,096,597 $ 5,731,626 Deferred financing costs (1) (17,462 ) (15,272 ) Net book value of secured debt $ 6,079,135 $ 5,716,354 (1) Costs incurred in connection with our secured debt agreements are recorded on our consolidated balance sheet when incurred and recognized as a component of interest expense over the life of each related agreement. Credit Facilities During the nine months ended September 30, 2017, we added two new credit facilities related to our Multifamily Joint Venture, providing an aggregate additional $450.0 million of credit capacity, increased the maximum facility size of two of our existing credit facilities, providing an additional £250.0 million and €250.0 million of credit capacity, respectively, and converted one of our asset-specific financings to a $500.0 million credit facility. The following tables detail our credit facilities ($ in thousands): September 30, 2017 Maximum Collateral Credit Borrowings Lender Facility Size (1) Assets (2) Potential (3) Outstanding Available (3) Wells Fargo $ 2,000,000 $ 2,232,117 $ 1,724,227 $ 1,398,224 $ 326,003 MetLife 1,000,000 1,030,148 807,164 807,164 — Bank of America 750,000 818,359 641,066 641,066 — Citibank (4) 795,350 596,119 464,849 356,751 108,098 JP Morgan (5) 500,000 453,121 344,656 295,984 48,672 Deutsche Bank 500,000 393,564 295,743 295,743 — Société Générale (6) 472,560 332,761 266,000 266,000 — Morgan Stanley (7) 669,900 422,332 331,037 211,105 119,932 Bank of America - Multi. JV (8) 200,000 87,000 69,600 69,600 — Goldman Sachs - Multi. JV (8) 250,000 59,125 45,008 45,008 — $ 7,137,810 $ 6,424,646 $ 4,989,350 $ 4,386,645 $ 602,705 December 31, 2016 Maximum Collateral Credit Borrowings Lender Facility Size (1) Assets (2) Potential (3) Outstanding Available (3) Wells Fargo $ 2,000,000 $ 1,718,874 $ 1,339,942 $ 1,107,733 $ 232,209 MetLife 1,000,000 1,106,017 862,454 862,454 — Bank of America 750,000 794,881 617,694 617,694 — JP Morgan (5) 500,000 550,560 420,414 316,219 104,195 Morgan Stanley (7) 308,500 344,056 272,221 231,930 40,291 Citibank (4) 500,000 508,989 394,677 229,629 165,048 Société Générale (6) 420,680 274,351 207,178 207,178 — $ 5,479,180 $ 5,297,728 $ 4,114,580 $ 3,572,837 $ 541,743 (1) Maximum facility size represents the largest amount of borrowings available under a given facility once sufficient collateral assets have been approved by the lender and pledged by us. (2) Represents the principal balance of the collateral assets. (3) Potential borrowings represents the total amount we could draw under each facility based on collateral already approved and pledged. When undrawn, these amounts are immediately available to us at our sole discretion under the terms of each credit facility. (4) As of September 30, 2017, the Citibank maximum facility size was composed of a general $500.0 million facility size denominated in U.S. Dollars plus a general €250.0 million ($295.4 million) facility size that contemplated British Pound Sterling and Euro borrowings. As of December 31, 2016, the maximum facility size was composed of a general $500.0 million facility. (5) As of September 30, 2017 and December 31, 2016, the JP Morgan maximum facility size was composed of a general $500.0 million facility size, under which U.S. Dollars and British Pound Sterling borrowings are contemplated. (6) As of September 30, 2017 and December 31, 2016, the Société Générale maximum facility size was composed of a €400.0 million facility size that was translated to $472.6 million and $420.7 million, respectively. Borrowings denominated in U.S. Dollars, British Pound Sterling, and Euro are contemplated under this facility. (7) As of September 30, 2017, the Morgan Stanley maximum facility size was composed of a £500.0 million facility size that was translated to $669.9 million. As of December 31, 2016, the maximum facility size was composed of a £250.0 million facility size that was translated to $308.5 million. Borrowings denominated in U.S. Dollars, British Pound Sterling, and Euro are contemplated under this facility. (8) These facilities finance the loan investments of our consolidated Multifamily Joint Venture. Refer to Note 2 for additional discussion of our Multifamily Joint Venture. The weighted-average outstanding balance of our credit facilities was $4.0 billion for the nine months ended September 30, 2017. As of September 30, 2017, we had aggregate borrowings of $4.4 billion outstanding under our credit facilities, with a weighted-average cash coupon of LIBOR plus 1.88% per annum, a weighted-average all-in cost of credit, including associated fees and expenses, of LIBOR plus 2.09% per annum, and a weighted-average advance rate of 78.8%. As of September 30, 2017, outstanding borrowings under these facilities had a weighted-average maturity, excluding extension options and term-out provisions, of 1.5 years. The weighted-average outstanding balance of our credit facilities was $2.9 billion for the nine months ended September 30, 2016. As of December 31, 2016, we had aggregated borrowings of $3.6 billion outstanding under our credit facilities, with a weighted-average cash coupon of LIBOR plus 1.82% per annum, a weighted-average all-in cost of credit, including associated fees and expenses, of LIBOR plus 2.02% per annum, and a weighted-average advance rate of 79.1%. As of December 31, 2016, outstanding borrowings under these facilities had a weighted-average maturity, excluding extension options and term-out provisions, of 1.5 years. Borrowings under each facility are subject to the initial approval of eligible collateral loans by the lender and the maximum advance rate and pricing rate of individual advances are determined with reference to the attributes of the respective collateral loan. The following tables outline the key terms of our credit facilities as of September 30, 2017: Lender Currency Guarantee (1) Margin Call (2) Term/Maturity Wells Fargo $ 25% Collateral marks only Term matched (3) MetLife $ 50% Collateral marks only April 21, 2023 (4) Bank of America $ 50% Collateral marks only May 21, 2021 (5) Société Générale $ / £ / € 25% Collateral marks only Term matched (3) Deutsche Bank $ 35% Collateral marks only Term matched (3) Citibank $ / £ / € 25% Collateral marks only Term matched (3) Morgan Stanley $ / £ / € 25% Collateral marks only March 3, 2020 JP Morgan $ / £ 50% Collateral marks only January 7, 2020 Bank of America - Multi. JV (6) $ 43% Collateral marks only July 19, 2021 Goldman Sachs - Multi. JV (6) $ 25% Collateral marks only July 12, 2020 (1) Other than amounts guaranteed based on specific collateral asset types, borrowings under our credit facilities are non-recourse to us. (2) Margin call provisions under our credit facilities do not permit valuation adjustments based on capital markets events, and are limited to collateral-specific credit marks. (3) These credit facilities have various availability periods during which new advances can be made and which are generally subject to each lender’s discretion. Maturity dates for advances outstanding are tied to the term of each respective collateral asset. (4) Includes five one-year extension options which may be exercised at our sole discretion. (5) Includes two one-year extension options which may be exercised at our sole discretion. (6) These facilities finance the loan investments of our consolidated Multifamily Joint Venture. Refer to Note 2 for additional discussion of our Multifamily Joint Venture. Currency Outstanding Potential (1) Index Rate (2) Advance (3) $ $ 4,123,064 $ 4,610,777 1-month USD LIBOR L+1.86% 78.8% € € 66,186 € 87,786 3-month EURIBOR L+2.24% 80.0% £ £ 138,371 £ 205,152 3-month GBP LIBOR L+2.24% 78.6% $ 4,386,645 $ 4,989,350 L+1.88% 78.8% (1) Potential borrowings represents the total amount we could draw under each facility based on collateral already approved and pledged. When undrawn, these amounts are immediately available to us at our sole discretion under the terms of each credit facility. (2) Represents weighted-average cash coupon based on borrowings outstanding. (3) Represents weighted-average advance rate based on the outstanding principal balance of the collateral assets pledged. GE Portfolio Acquisition Facility During the second quarter of 2015, concurrently with our acquisition of the GE portfolio, we entered into an agreement with Wells Fargo to provide us with secured financing for the acquired portfolio. As of September 30, 2017, this facility provided for $1.2 billion of financing, of which $1.1 billion was outstanding and an additional $129.4 million was available to finance future loan fundings in the GE portfolio. The GE portfolio acquisition facility is non-revolving and consists of a single master repurchase agreement providing for asset-specific borrowings for each collateral asset. The asset-specific borrowings under the GE portfolio acquisition facility were advanced at a weighted-average rate of 80% of our purchase price of the collateral assets and are repaid pro rata from collateral asset repayment proceeds. The asset-specific borrowings are currency matched to the collateral assets and accrue interest at a rate equal to the sum of (i) the applicable base rate plus (ii) a margin of 1.75%, which will increase to 1.80% and 1.85% in year four and year five, respectively. As of September 30, 2017, those borrowings were denominated in U.S. Dollars, Canadian Dollars, and British Pounds Sterling. The asset-specific borrowings are term matched to the underlying collateral assets with an outside maturity date of May 20, 2020, which may be extended pursuant to two one-year extension options. We guarantee obligations under the GE portfolio acquisition facility in an amount equal to the greater of (i) 25% of outstanding asset-specific borrowings, and (ii) $250.0 million. We had outstanding asset-specific borrowings under the GE portfolio acquisition facility of $1.1 billion and a weighted-average all-in cost of credit, including associated fees and expenses, of LIBOR plus 1.75% per annum as of September 30, 2017, compared to $1.5 billion of outstanding asset-specific borrowings and a weighted-average all-in cost of credit, including associated fees and expenses, of LIBOR plus 1.83% per annum as of December 31, 2016. Asset-Specific Financings The following tables detail our asset-specific financings ($ in thousands): September 30, 2017 Asset-Specific Financings Count Principal Book Value Wtd. Avg. (1) Guarantee (2) Wtd. Avg. (3) Collateral assets 5 $ 662,223 $ 659,152 L+4.70 % n/a Dec. 2020 Financing provided (4) 5 $ 517,256 $ 516,537 L+2.48 % $ 162,517 Dec. 2020 (1) These floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) Other than amounts guaranteed on an asset-by-asset basis, borrowings under our asset-specific financings are non-recourse to us. (3) The weighted-average term is determined based on the maximum maturity of the corresponding loans, assuming all extension options are exercised by the borrower. Each of our asset-specific financings are term-matched to the corresponding collateral loans. (4) Borrowings of $394.8 million under these asset specific financings are cross collateralized with related credit facilities with the same lenders. December 31, 2016 Asset-Specific Financings Count Principal Book Value Wtd. Avg. (1) Guarantee (2) Wtd. Avg. (3) Collateral assets 7 $ 876,083 $ 869,417 L+4.84 % n/a Aug. 2020 Financing provided (4) 7 $ 679,207 $ 676,333 L+2.60 % $ 231,585 Aug. 2020 (1) These floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) Other than amounts guaranteed on an asset-by-asset basis, borrowings under our asset-specific financings are non-recourse to us. (3) The weighted-average term is determined based on the maximum maturity of the corresponding loans, assuming all extension options are exercised by the borrower. Each of our asset-specific financings are term-matched to the corresponding collateral loans. (4) Borrowings of $392.3 million under these asset specific financings are cross collateralized with related credit facilities with the same lenders. The weighted-average outstanding balance of our asset-specific financings was $596.2 million for the nine months ended September 30, 2017 and $557.9 million for the nine months ended September 30, 2016. Revolving Credit Agreement During the second quarter of 2017, we increased the borrowing capacity under our secured revolving credit agreement with Barclays by $125.0 million to $250.0 million. This full recourse facility is designed to finance first mortgage originations for up to six months as a bridge to term financing or syndication. Advances under the agreement are subject to availability under a specified borrowing base and accrue interest at a per annum pricing rate equal to the sum of (i) an applicable base rate or Eurodollar rate and (ii) an applicable margin, in each case, dependent on the applicable type of loan collateral. The maturity date of the facility is April 4, 2020. During the nine months ended September 30, 2017, the weighted-average outstanding borrowings under the revolving credit agreement were $23.5 million and we recorded interest expense of $1.7 million, including $575,000 of amortization of deferred fees and expenses. As of September 30, 2017, we had $101.8 million of borrowings outstanding under the agreement. During the nine months ended September 30, 2016, the weighted-average outstanding borrowings under the revolving credit agreement were $19.5 million and we recorded interest expense of $915,000, including $248,000 of amortization of deferred fees and expenses. As of December 31, 2016 we had no outstanding borrowings under the agreement. Debt Covenants Each of the guarantees related to our secured debt agreements contain the following uniform financial covenants: (i) our ratio of earnings before interest, taxes, depreciation, and amortization, or EBITDA, to fixed charges, as defined in the agreements, shall be not less than 1.4 to 1.0; (ii) our tangible net worth, as defined in the agreements, shall not be less than $1.9 billion as of each measurement date plus 75% of the net cash proceeds of future equity issuances subsequent to September 30, 2017; (iii) cash liquidity shall not be less than the greater of (x) $10.0 million or (y) 5% of our recourse indebtedness; and (iv) our indebtedness shall not exceed 83.33% of our total assets. As of September 30, 2017 and December 31, 2016, we were in compliance with these covenants.

Loan Participations Sold, Net

Loan Participations Sold, Net	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Loan Participations Sold, Net	7. LOAN PARTICIPATIONS SOLD, NET The financing of a loan by the non-recourse sale of a senior interest in the loan through a participation agreement generally does not qualify as a sale under GAAP. Therefore, in the instance of such sales, we present the whole loan as an asset and the loan participation sold as a liability on our consolidated balance sheet until the loan is repaid. The obligation to pay principal and interest on these liabilities is generally based on the performance of the related loan obligation. The gross presentation of loan participations sold does not impact stockholders’ equity or net income. The following tables detail our loan participations sold ($ in thousands): September 30, 2017 Loan Participations Sold Count Principal Book Value Yield/Cost (1) Guarantee (2) Term Total loan 1 $ 93,710 $ 91,498 L+5.96 % n/a Feb. 2022 Senior participation (3) 1 33,193 33,193 L+4.00 % n/a Feb. 2022 December 31, 2016 Loan Participations Sold Count Principal Book Value Yield/Cost (1) Guarantee (2) Term Total loan 1 $ 419,560 $ 416,233 L+4.48 % n/a Dec. 2019 Senior participation (3)(4) 1 349,633 348,077 L+2.72 % $ 29,616 Dec. 2019 (1) Our floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred fees / financing costs. (2) As of September 30, 2017, our loan participation sold was non-recourse to us. As of December 31, 2016, our loan participation was subject to a related guarantee agreement for £24.0 million ($29.6 million as of December 31, 2016). (3) During the three and nine months ended September 30, 2017, we recorded $4.0 million and $9.3 million, respectively, of interest expense related to our loan participations sold, of which $2.6 million and $7.7 million was paid in cash. During the three and nine months ended September 30, 2016, we recorded $3.4 million and $10.7 million, respectively, of interest expense related to our loan participations sold, of which $3.2 million and $10.3 million was paid in cash. (4) The difference between principal balance and book value of loan participations sold is due to deferred financing costs of $1.6 million as of December 31, 2016.

Securitized Debt Obligations, N

Securitized Debt Obligations, Net	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Securitized Debt Obligations, Net	8. SECURITIZED DEBT OBLIGATIONS, NET In the second quarter of 2017, we financed one of our loans through a single asset securitization vehicle, or the Securitization, which is consolidated in our financial statements. The Securitization has issued securitized debt obligations that are non-recourse to us. Refer to Note 16 for further discussion of our Securitization. The following table details our securitized debt obligations ($ in thousands): September 30, 2017 Securitized Debt Obligations Count Principal Book Value Yield/Cost (1) Term (2) Total loan 1 $ 644,788 $ 641,262 L+3.60 % June 2023 Securitized debt obligations (3) 1 474,620 474,298 L+1.94 % June 2033 (1) In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) Loan term represents final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitization. (3) During the three and nine months ended September 30, 2017, we recorded $3.8 million of interest expense related to our securitized debt obligations. We did not have any securitized debt obligations as of December 31, 2016.

Convertible Notes, Net

Convertible Notes, Net	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Convertible Notes, Net	9. CONVERTIBLE NOTES, NET As of September 30, 2017, the following convertible senior notes, or Convertible Notes, were outstanding ($ in thousands): Convertible Notes Issuance Face Value Coupon Rate All-in Cost (1) Conversion Rate (2) Maturity November 2013 $ 172,500 5.25 % 5.87 % 36.1380 December 1, 2018 May 2017 402,500 4.38 % 4.85 % 28.0324 May 5, 2022 (1) Includes issuance costs that are amortized through interest expense over the life of the Convertible Notes using the effective interest method. (2) Represents the shares of class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to a conversion price of $27.67 and $35.67 per share of class A common stock, respectively, for the November 2013 and May 2017 convertible notes. As a result of exceeding the cumulative dividend threshold, as defined in the November 2013 convertible notes supplemental indenture, the conversion rate on the November 2013 convertible notes was most recently adjusted on June 28, 2017 from the prior conversion rate of 35.7236 shares of class A common stock per $1,000 principal amount of convertible notes, which was equivalent to a conversion price of $27.99 per share of class A common stock. The cumulative dividend threshold as defined in the May 2017 convertible notes supplemental indenture has not been exceeded as of September 30, 2017. In May 2017 we issued $287.5 million of convertible notes. In the third quarter of 2017, we issued an additional $115.0 million of convertible notes under the same indenture and with the same terms as the May 2017 convertible notes. Accordingly, as of September 30, 2017, the May 2017 convertible notes had an aggregate outstanding face value of $402.5 million. The Convertible Notes are convertible at the holders’ option into shares of our class A common stock, only under specific circumstances, prior to the close of business on August 31, 2018 and January 31, 2022, for the November 2013 and May 2017 convertible notes, respectively, at the applicable conversion rate in effect on the conversion date. Thereafter, the Convertible Notes are convertible at the option of the holder at any time until the second scheduled trading day immediately preceding the maturity date. Neither series of the Convertible Notes were convertible as of September 30, 2017. We may not redeem the Convertible Notes prior to maturity. The last reported sale price of our class A common stock of $31.02 on September 29, 2017, the last trading day in the quarter ended September 30, 2017, was greater than the per share conversion price of the November 2013 convertible notes but less than the per share conversion price of the May 2017 convertible notes. We have the intent and ability to settle each series of the Convertible Notes in cash and, as a result, the Convertible Notes did not have any impact on our diluted earnings per share. Upon our issuance of the November 2013 convertible notes, we recorded a $9.1 million discount based on the implied value of the conversion option and an assumed effective interest rate of 6.50%, as well as $4.1 million of initial issuance costs. Including the amortization of this discount and the issuance costs, our total cost of the November 2013 convertible notes issuance is 7.16% per annum. Upon our issuance of the May 2017 convertible notes, including our additional issuance in the third quarter of 2017, we recorded a $979,000 discount based on the implied value of the conversion option and an assumed effective interest rate of 4.57%, as well as $8.4 million of initial debt discount and issuance costs. Including the amortization of the discount and issuance costs, our total cost of the May 2017 convertible notes issuance is 4.91% per annum. The following table details our interest expense related to the Convertible Notes ($ in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Cash coupon $ 6,247 $ 2,264 $ 12,732 $ 6,792 Discount and issuance cost amortization 1,202 691 2,869 2,038 Total interest expense $ 7,449 $ 2,955 $ 15,601 $ 8,830 The following table details the net book value of our Convertible Notes on our consolidated balance sheets ($ in thousands): September 30, 2017 December 31, 2016 Face value $ 575,000 $ 172,500 Unamortized discount (11,386 ) (5,532 ) Deferred financing costs (873 ) (206 ) Net book value $ 562,741 $ 166,762 Accrued interest payable for the Convertible Notes was $9.0 million and $755,000 as of September 30, 2017 and December 31, 2016, respectively. Refer to Note 2 for additional discussion of our accounting policies for the Convertible Notes.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	10. DERIVATIVE FINANCIAL INSTRUMENTS The sole objective of our use of derivative financial instruments is to minimize the risks and/or costs associated with our investments and/or financing transactions. These derivatives may or may not qualify as net investment, cash flow, or fair value hedges under the hedge accounting requirements of ASC 815 – “Derivatives and Hedging.” Derivatives not designated as hedges are not speculative and are used to manage our exposure to interest rate movements and other identified risks. For more information on the accounting for designated and non-designated hedges, refer to Note 2. The use of derivative financial instruments involves certain risks, including the risk that the counterparties to these contractual arrangements do not perform as agreed. To mitigate this risk, we only enter into derivative financial instruments with counterparties that have appropriate credit ratings and are major financial institutions with which we and our affiliates may also have other financial relationships. We do not anticipate that any of the counterparties will fail to meet their obligations. Net Investment Hedges of Foreign Currency Risk Certain of our international investments expose us to fluctuations in foreign interest rates and currency exchange rates. These fluctuations may impact the value of our cash receipts and payments in terms of our functional currency, the U.S. Dollar. We use foreign currency forward contracts to protect the value or fix the amount of certain investments or cash flows in terms of the U.S. Dollar. The following table details our outstanding foreign exchange derivatives that were designated as net investment hedges of foreign currency risk (notional amount in thousands): September 30, 2017 December 31, 2016 Foreign Currency Derivatives Number of Notional Foreign Currency Derivatives Number of Notional Sell GBP Forward 1 £ 112,700 Sell GBP Forward 2 £ 141,900 Sell CAD Forward 1 C$ 102,000 Sell CAD Forward 2 C$ 122,900 Sell EUR Forward 1 € 44,900 Cash Flow Hedges of Interest Rate Risk Certain of our financing transactions expose us to a fixed versus floating rate mismatch between our assets and liabilities. We use derivative financial instruments, which include interest rate caps and swaps, and may also include interest rate options, floors, and other interest rate derivative contracts, to hedge interest rate risk associated with our borrowings where there is potential for an index mismatch. The following tables detail our outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk (notional amount in thousands): September 30, 2017 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Swaps 4 C$ 108,183 1.0% CDOR 1.7 Interest Rate Caps 9 $ 204,248 2.4% USD LIBOR 1.7 Interest Rate Caps 3 C$ 23,370 2.0% CDOR 0.6 December 31, 2016 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Swaps 4 C$ 108,271 1.0% CDOR 2.4 Interest Rate Caps 21 $ 802,256 2.0% USD LIBOR 0.4 Interest Rate Caps 5 C$ 400,035 2.0% CDOR 0.4 Interest Rate Cap 1 £ 15,142 2.0% GBP LIBOR 0.3 Amounts reported in accumulated other comprehensive income (loss) related to derivatives will be reclassified to interest expense as interest payments are made on our floating rate debt. During the twelve months following September 30, 2017, we estimate that an additional $561,000 will be reclassified from accumulated other comprehensive income (loss) as an increase to interest income. Non-designated Hedges During the three and nine months ended September 30, 2017, we recorded losses of $42,000 and $355,000, respectively, related to non-designated hedges that were reported as a component of interest expense in our consolidated financial statements. During the three and nine months ended September 30, 2016, we recorded losses of $528,000 and $2.2 million, respectively. The following tables summarize our non-designated hedges (notional amount in thousands): September 30, 2017 Non-designated Hedges Number of Notional Buy USD / Sell GBP Forward 1 £ 35,000 Buy GBP / Sell USD Forward 1 £ 35,000 Buy USD / Sell CAD Forward 1 C$ 15,000 Buy CAD / Sell USD Forward 1 C$ 15,000 Buy GBP / Sell EUR Forward 1 € 12,857 December 31, 2016 Non-designated Hedges Number of Notional Interest Rate Caps 3 $ 256,875 Interest Rate Caps 2 C$ 37,221 Buy GBP / Sell EUR Forward 1 € 12,857 Valuation of Derivative Instruments The following table summarizes the fair value of our derivative financial instruments ($ in thousands): Fair Value of Derivatives in an Asset Position (1) Fair Value of Derivatives in a Liability Position (2) September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Derivatives designated as hedging instruments: Foreign exchange contracts $ — $ 3,268 $ 5,617 $ 210 Interest rate derivatives 1,238 331 — — Total derivatives designated as hedging instruments $ 1,238 $ 3,599 $ 5,617 $ 210 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 390 $ 487 $ 1,550 $ — Interest rate derivatives — — — — Total derivatives not designated as hedging instruments $ 390 $ 487 $ 1,550 $ — Total Derivatives $ 1,628 $ 4,086 $ 7,167 $ 210 (1) Included in other assets in our consolidated balance sheets. (2) Included in other liabilities in our consolidated balance sheets. The following table presents the effect of our derivative financial instruments on our consolidated statements of operations ($ in thousands): Amount of Gain (Loss) Recognized in OCI on Derivatives Location of Gain (Loss) Reclassified from OCI into Income Amount of Gain (Loss) Reclassified from Accumulated OCI into Income Derivatives in Hedging Relationships Three Months 2017 Nine Months 2017 Three Months 2017 Nine Months 2017 Net Investment Hedges Foreign exchange contracts (1) $ (8,524 ) $ (21,757 ) Interest Expense $ — $ — Cash Flow Hedges Interest rate derivatives 536 707 Interest Income (Expense) (2) 41 (900 ) Total $ (7,988 ) $ (21,050 ) $ 41 $ (900 ) (1) During the three and nine months ended September 30, 2017, we paid net cash settlements of $8.7 million and $11.8 million, respectively, on our foreign currency forward contracts, compared to receiving $19.2 million and $17.4 million during the same periods in 2016. Those amounts are included as a component of accumulated other comprehensive loss on our consolidated balance sheets. (2) During the three months ended September 30, 2017, we recorded total interest and related income of $146.4 million which included interest income of $41,000 related to our cash flow hedges. During the nine months ended September 30, 2017, we incurred total interest and related expenses of $168.9 million which included $900,000 related to our cash flow hedges. Credit-Risk Related Contingent Features We have entered into agreements with certain of our derivative counterparties that contain provisions where if we were to default on any of our indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, we may also be declared in default on our derivative obligations. In addition, certain of our agreements with our derivative counterparties require that we post collateral to secure net liability positions. As of September 30, 2017, we were in a net liability position with each such derivative counterparty and posted collateral of $7.8 million. As of December 31, 2016 we were in a net asset position with each such derivative counterparty and posted collateral of $79,000.

Equity

Equity	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Equity	11. EQUITY Stock and Stock Equivalents Authorized Capital As of September 30, 2017, we had the authority to issue up to 300,000,000 shares of stock, consisting of 200,000,000 shares of class A common stock and 100,000,000 shares of preferred stock. Subject to applicable NYSE listing requirements, our board of directors is authorized to cause us to issue additional shares of authorized stock without stockholder approval. In addition, to the extent not issued, currently authorized stock may be reclassified between class A common stock and preferred stock. We did not have any shares of preferred stock issued and outstanding as of September 30, 2017. Class A Common Stock and Deferred Stock Units Holders of shares of our class A common stock are entitled to vote on all matters submitted to a vote of stockholders and are entitled to receive such dividends as may be authorized by our board of directors and declared by us, in all cases subject to the rights of the holders of shares of outstanding preferred stock, if any. We also issue restricted class A common stock under our stock-based incentive plans. Refer to Note 14 for additional discussion of these long-term incentive plans. In addition to our class A common stock, we also issue deferred stock units to certain members of our board of directors in lieu of cash compensation for services rendered. These deferred stock units are non-voting, but carry the right to receive dividends in the form of additional deferred stock units in an amount equivalent to the cash dividends paid to holders of shares of class A common stock. The following table details the movement in our outstanding shares of class A common stock, including restricted class A common stock and deferred stock units: Nine Months Ended September 30, Common Stock Outstanding (1) 2017 2016 Beginning balance 94,709,290 93,843,847 Issuance of class A common stock (2) 971 812 Issuance of restricted class A common stock, net 286,773 209,798 Issuance of deferred stock units 20,560 20,850 Ending balance 95,017,594 94,075,307 (1) Includes deferred stock units held by members of our board of directors of 189,587 and 162,371 as of September 30, 2017 and 2016, respectively. (2) Consists of 971 and 812 shares issued under our dividend reinvestment program during the nine months ended September 30, 2017 and 2016, respectively. Dividend Reinvestment and Direct Stock Purchase Plan On March 25, 2014, we adopted a dividend reinvestment and direct stock purchase plan, under which we registered and reserved for issuance, in the aggregate, 10,000,000 shares of class A common stock. Under the dividend reinvestment component of this plan, our class A common stockholders can designate all or a portion of their cash dividends to be reinvested in additional shares of class A common stock. The direct stock purchase component allows stockholders and new investors, subject to our approval, to purchase shares of class A common stock directly from us. During the three and nine months ended September 30, 2017, we issued 428 shares and 971 shares, respectively, of class A common stock under the dividend reinvestment component of the plan compared to 262 shares and 812 shares for the same periods in 2016. As of September 30, 2017, a total of 9,997,356 shares of class A common stock remained available for issuance under the dividend reinvestment and direct stock purchase plan. At the Market Stock Offering Program On May 9, 2014, we entered into equity distribution agreements, or ATM Agreements, pursuant to which we may sell, from time to time, up to an aggregate sales price of $200.0 million of our class A common stock. On July 29, 2016, in connection with filing a new universal shelf registration statement on Form S-3, we entered into amendments to each of the ATM Agreements. Sales of class A common stock made pursuant to the ATM Agreements may be made in negotiated transactions or transactions that are deemed to be “at the market” offerings as defined in Rule 415 under the Securities Act of 1933, as amended. Actual sales will depend on a variety of factors including market conditions, the trading price of our class A common stock, our capital needs, and our determination of the appropriate sources of funding to meet such needs. We did not sell any shares of our class A common stock under the ATM Agreements during the nine months ended September 30, 2017 and 2016. As of September 30, 2017, sales of our class A common stock with an aggregate sales price of $188.6 million remained available for issuance under the ATM Agreements. Dividends We generally intend to distribute substantially all of our taxable income, which does not necessarily equal net income as calculated in accordance with GAAP, to our stockholders each year to comply with the REIT provisions of the Internal Revenue Code of 1986, as amended, or the Internal Revenue Code. Our dividend policy remains subject to revision at the discretion of our board of directors. All distributions will be made at the discretion of our board of directors and will depend upon our taxable income, our financial condition, our maintenance of REIT status, applicable law, and other factors as our board of directors deems relevant. On September 15, 2017, we declared a dividend of $0.62 per share, or $58.8 million, that was paid on October 13, 2017 to stockholders of record as of September 30, 2017. The following table details our dividend activity ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Dividends declared per share of common stock $ 0.62 $ 0.62 $ 1.86 $ 1.86 Total dividends declared $ 58,793 $ 58,226 $ 176,374 $ 174,678 Earnings Per Share We calculate our basic and diluted earnings per share using the two-class method for all periods presented as the unvested shares of our restricted class A common stock qualify as participating securities, as defined by GAAP. These restricted shares have the same rights as our other shares of class A common stock, including participating in any dividends, and therefore have been included in our basic and diluted net income per share calculation. Our Convertible Notes are excluded from dilutive earnings per share as we have the intent and ability to settle these instruments in cash. The following table sets forth the calculation of basic and diluted net income per share of class A common stock based on the weighted-average of both restricted and unrestricted class A common stock outstanding ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Net income (1) $ 57,722 $ 64,794 $ 159,741 $ 184,921 Weighted-average shares outstanding, basic and diluted 95,013,087 94,071,537 95,004,188 94,067,923 Per share amount, basic and diluted $ 0.61 $ 0.69 $ 1.68 $ 1.97 (1) Represents net income attributable to Blackstone Mortgage Trust, Inc. Other Balance Sheet Items Accumulated Other Comprehensive Loss As of September 30, 2017, total accumulated other comprehensive loss was $32.4 million, primarily representing (i) $63.5 million of cumulative unrealized currency translation adjustments on assets and liabilities denominated in foreign currencies and (ii) an offsetting $31.1 million of net realized and unrealized gains related to changes in the fair value of derivative instruments. As of December 31, 2016, total accumulated other comprehensive loss was $56.2 million, primarily representing (i) $107.5 million of cumulative unrealized currency translation adjustments on assets and liabilities denominated in foreign currencies and (ii) an offsetting $51.3 million of net realized and unrealized gains related to changes in the fair value of derivative instruments. Non-Controlling Interests The non-controlling interests included on our consolidated balance sheets represent the equity interests in our Multifamily Joint Venture that are not owned by us. A portion of our Multifamily Joint Venture’s consolidated equity and results of operations are allocated to these non-controlling interests based on their pro-rata ownership of our Multifamily Joint Venture. As of September 30, 2017, our Multifamily Joint Venture’s total equity was $41.2 million, of which $35.0 million was owned by Blackstone Mortgage Trust, and $6.2 million was allocated to non-controlling interests. As of December 31, 2016, we did not have any non-controlling interests on our consolidated financial statements.

Other Expenses

Other Expenses	9 Months Ended
	Sep. 30, 2017
Other Income and Expenses [Abstract]
Other Expenses	12. OTHER EXPENSES Our other expenses consist of the management and incentive fees we pay to our Manager and our general and administrative expenses. Management and Incentive Fees Pursuant to a management agreement between our Manager and us, or our Management Agreement, our Manager earns a base management fee in an amount equal to 1.50% per annum multiplied by our outstanding equity balance, as defined in the Management Agreement. In addition, our Manager is entitled to an incentive fee in an amount equal to the product of (i) 20% and (ii) the excess of (a) our Core Earnings (as defined in our Management Agreement) for the previous 12-month period over (b) an amount equal to 7.00% per annum multiplied by our outstanding Equity, provided that our Core Earnings over the prior three-year period is greater than zero. Core Earnings, as defined in our Management Agreement, is generally equal to our net income (loss) prepared in accordance with GAAP, excluding (i) certain non-cash items (ii) the net income (loss) related to our legacy portfolio and (iii) incentive management fees. During the three and nine months ended September 30, 2017, we incurred $9.5 million and $28.6 million, respectively, of management fees payable to our Manager, compared to $9.5 million and $28.4 million during the same periods in 2016. In addition, during the three and nine months ended September 30, 2017, we incurred $3.7 million and $11.9 million, respectively, of incentive fees payable to our Manager, compared to $4.2 million and $14.8 million during the same periods in 2016. As of September 30, 2017 and December 31, 2016, we had accrued management and incentive fees payable to our Manager of $13.2 million and $12.8 million, respectively. General and Administrative Expenses General and administrative expenses consisted of the following ($ in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Professional services (1) $ 933 $ 828 $ 2,811 $ 2,474 Operating and other costs (1) 489 305 1,424 1,695 Subtotal 1,422 1,133 4,235 4,169 Non-cash and CT Legacy Portfolio compensation expenses Management incentive awards plan - CTOPI (2) — 938 — 1,106 Management incentive awards plan - CT Legacy Partners (3) — 354 — 1,112 Restricted class A common stock earned 5,819 4,855 17,496 14,190 Director stock-based compensation 125 94 313 282 Subtotal 5,944 6,241 17,809 16,690 Total BXMT expenses 7,366 7,374 22,044 20,859 Other expenses 53 40 175 131 Total general and administrative expenses $ 7,419 $ 7,414 $ 22,219 $ 20,990 (1) During the three and nine months ended September 30, 2017 we recognized an aggregate $112,000 of expenses related to our Multifamily Joint Venture. (2) Represents the portion of CTOPI promote revenue recorded under compensation awards. See Note 4 for further discussion. (3) Represents the amounts recorded under the CT Legacy Partners management incentive awards during the period. See below for discussion of the CT Legacy Partners management incentive awards plan. CT Legacy Partners Management Incentive Awards Plan In conjunction with our March 2011 restructuring, we created an employee pool for up to 6.75% of the distributions paid to the common equity holders of our subsidiary, CT Legacy Partners (subject to certain caps and priority distributions). During the three and nine months ended September 30, 2016 we recognized $354,000 and $1.1 million, respectively, of expenses under the CT Legacy Partners incentive plan. Our investment in CT Legacy Partners was substantially realized as of December 31, 2016.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	13. INCOME TAXES We elected to be taxed as a REIT, effective January 1, 2003, under the Internal Revenue Code for U.S. federal income tax purposes. We generally must distribute annually at least 90% of our net taxable income, subject to certain adjustments and excluding any net capital gain, in order for U.S. federal income tax not to apply to our earnings that we distribute. To the extent that we satisfy this distribution requirement, but distribute less than 100% of our net taxable income, we will be subject to U.S. federal income tax on our undistributed taxable income. In addition, we will be subject to a 4% nondeductible excise tax if the actual amount that we pay out to our stockholders in a calendar year is less than a minimum amount specified under U.S. federal tax laws. Our qualification as a REIT also depends on our ability to meet various other requirements imposed by the Internal Revenue Code, which relate to organizational structure, diversity of stock ownership, and certain restrictions with regard to the nature of our assets and the sources of our income. Even if we qualify as a REIT, we may be subject to certain U.S. federal income and excise taxes and state and local taxes on our income and assets. If we fail to maintain our qualification as a REIT for any taxable year, we may be subject to material penalties as well as federal, state, and local income tax on our taxable income at regular corporate rates and we would not be able to qualify as a REIT for the subsequent four full taxable years. As of September 30, 2017 and December 31, 2016, we were in compliance with all REIT requirements. During the three and nine months ended September 30, 2017, we recorded a current income tax provision of $83,000 and $265,000, respectively, primarily related to activities of our taxable REIT subsidiaries and various state and local taxes. During the three and nine months ended September 30, 2016, we recorded an income tax provision of $194,000 and $281,000, respectively. We did not have any deferred tax assets or liabilities as of September 30, 2017 or December 31, 2016. We have net operating losses, or NOLs, generated by our predecessor business that may be carried forward and utilized in current or future periods. As a result of our issuance of 25,875,000 shares of class A common stock in May 2013, the availability of our NOLs is generally limited to $2.0 million per annum by change of control provisions promulgated by the Internal Revenue Service with respect to the ownership of Blackstone Mortgage Trust. As of December 31, 2016, we had NOLs of $159.0 million that will expire in 2029, unless they are utilized by us prior to expiration. As of September 30, 2017, tax years 2014 through 2016 remain subject to examination by taxing authorities.

Stock-Based Incentive Plans

Stock-Based Incentive Plans	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Incentive Plans	14. STOCK-BASED INCENTIVE PLANS We are externally managed by our Manager and do not currently have any employees. However, as of September 30, 2017, our Manager, certain individuals employed by an affiliate of our Manager, and certain members of our board of directors were compensated, in part, through the issuance of stock-based instruments. We had stock-based incentive awards outstanding under seven benefit plans as of September 30, 2017: (i) our amended and restated 1997 non-employee director stock plan, or 1997 Plan; (ii) our 2007 long-term incentive plan, or 2007 Plan; (iii) our 2011 long-term incentive plan, or 2011 Plan; (iv) our 2013 stock incentive plan, or 2013 Plan; (v) our 2013 manager incentive plan, or 2013 Manager Plan; (vi) our 2016 stock incentive plan, or 2016 Plan; and (vii) our 2016 manager incentive plan, or 2016 Manager Plan. We refer to our 1997 Plan, our 2007 Plan, our 2011 Plan, our 2013 Plan, and our 2013 Manager Plan, collectively, as our Expired Plans and we refer to our 2016 Plan and 2016 Manager Plan, collectively, as our Current Plans. Our Expired Plans have expired and no new awards may be issued under them. Under our Current Plans, a maximum of 2,400,000 shares of our class A common stock may be issued to our Manager, our directors and officers, and certain employees of affiliates of our Manager. As of September 30, 2017, there were 1,448,852 shares available under the Current Plans. The following table details the movement in our outstanding shares of restricted class A common stock and the weighted-average grant date fair value per share: Restricted Class A Weighted-Average Balance as of December 31, 2016 1,309,995 $ 28.68 Granted 289,896 30.55 Vested (335,536 ) 27.78 Forfeited (3,123 ) 27.37 Balance as of September 30, 2017 1,261,232 $ 29.35 These shares generally vest in installments over a three-year period, pursuant to the terms of the respective award agreements and the terms of the Current Plans. The 1,261,232 shares of restricted class A common stock outstanding as of September 30, 2017 will vest as follows: 412,480 shares will vest in 2017; 542,789 shares will vest in 2018; 305,218 shares will vest in 2019; and 745 shares will vest in 2020. As of September 30, 2017, total unrecognized compensation cost relating to nonvested share-based compensation arrangements was $29.8 million based on the closing price of our class A common stock of $31.02 on September 29, 2017, the last trading day in the quarter ended September 30, 2017. This cost is expected to be recognized over a weighted average period of 1.0 years from September 30, 2017.

Fair Values

Fair Values	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Values	15. FAIR VALUES Assets and Liabilities Measured at Fair Value The following table summarizes our assets and liabilities measured at fair value on a recurring basis ($ in thousands): September 30, 2017 December 31, 2016 Level 1 Level 2 Level 3 Fair Value Level 1 Level 2 Level 3 Fair Value Assets Derivatives $ — $ 1,628 $ — $ 1,628 $ — $ 4,086 $ — $ 4,086 Liabilities Derivatives $ — $ 7,167 $ — $ 7,167 $ — $ 210 $ — $ 210 The following table reconciles the beginning and ending balances of assets measured at fair value on a recurring basis using Level 3 inputs ($ in thousands): Nine Months Ended September 30, 2017 2016 (1) January 1, $ — $ 12,561 Proceeds from investment realizations — (2,406 ) Transfers out of level 3 (2) — (20,745 ) Adjustments to fair value included in earnings Gain on investments at fair value — 11,790 September 30, $ — $ 1,200 (1) All assets measured at fair value on a recurring basis using Level 3 inputs were included as a component of other assets in the consolidated Balance Sheets. (2) During the second quarter of 2016, $20.7 million of collateralized debt obligations, or CDOs, were transferred out of Level 3 and into Level 1 as a result of a binding agreement to sell the underlying collateral assets of the CDO to an independent third-party. These investments were realized in the third quarter of 2016. Refer to Note 2 for further discussion regarding fair value measurement. Fair Value of Financial Instruments As discussed in Note 2, GAAP requires disclosure of fair value information about financial instruments, whether or not recognized in the statement of financial position, for which it is practicable to estimate that value. The following table details the carrying amount, face amount, and fair value of the financial instruments described in Note 2 ($ in thousands): September 30, 2017 December 31, 2016 Carrying Face Fair Carrying Face Fair Amount Amount Value Amount Amount Value Financial assets Cash and cash equivalents $ 61,221 $ 61,221 $ 61,221 $ 75,567 $ 75,567 $ 75,567 Restricted cash 32,864 32,864 32,864 — — — Loans receivable, net 9,637,152 9,681,055 9,685,422 8,692,978 8,727,218 8,733,784 Financial liabilities Secured debt agreements, net 6,079,135 6,096,597 6,096,597 5,716,354 5,731,626 5,731,626 Loan participations sold, net 33,193 33,193 33,193 348,077 349,633 349,633 Securitized debt obligations, net 474,298 474,620 474,655 — — — Convertible notes, net 562,741 575,000 602,503 166,762 172,500 191,763 Estimates of fair value for cash and cash equivalents, restricted cash, and convertible notes are measured using observable, quoted market prices, or Level 1 inputs. Estimates of fair value for securitized debt obligations are measured using observable, quoted market prices, in inactive markets, or Level 2 inputs. All other fair value significant estimates are measured using unobservable inputs, or Level 3 inputs. See Note 2 for further discussion regarding fair value measurement of certain of our assets and liabilities.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	16. VARIABLE INTEREST ENTITIES In the second quarter of 2017, we financed one of our loans through the Securitization, which is a VIE. We are the primary beneficiary and consolidate the Securitization on our balance sheet as we (i) control the subordinate tranche of the Securitization, which we believe gives us the power to direct the activities that most significantly affect the Securitization, and (ii) have the right to receive benefits and obligation to absorb losses of the Securitization through the subordinate interests we own. The following table details the assets and liabilities of our consolidated Securitization VIE ($ in thousands): September 30, 2017 December 31, 2016 Assets: Loans receivable, net $ 500,000 $ — Other assets 763 — Total assets $ 500,763 $ — Liabilities: Securitized debt obligations, net $ 474,298 $ — Other liabilities 604 — Total liabilities $ 474,902 $ — Assets held by the Securitization are restricted and can be used only to settle obligations of the Securitization, including the subordinate interests owned by us. The liabilities of the Securitization are non-recourse to us and can only be satisfied from the assets of the Securitization. The consolidation of the Securitization results in an increase in our gross assets, liabilities, interest income and interest expense, however it does not affect our stockholders’ equity or net income. We are not obligated to provide, have not provided, and do not intend to provide financial support to the Securitization.

Transactions with Related Parti

Transactions with Related Parties	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Transactions with Related Parties	17. TRANSACTIONS WITH RELATED PARTIES We are managed by our Manager pursuant to the Management Agreement, the current term of which expires on December 19, 2017, and will be automatically renewed for a one-year term each anniversary thereafter unless earlier terminated. As of September 30, 2017 and December 31, 2016, our consolidated balance sheet included $13.2 million and $12.8 million of accrued management and incentive fees payable to our Manager, respectively. During the three and nine months ended September 30, 2017, we paid management and incentive fees of $14.4 million and $40.1 million, respectively, to our Manager, compared to $15.8 million and $43.8 million during the same periods of 2016. In addition, during the three and nine months ended September 30, 2017, we reimbursed our Manager for expenses incurred on our behalf of $59,000 and $325,000, respectively, compared to $82,000 and $462,000 during the same periods of 2016. During the three and nine months ended September 30, 2016, CT Legacy Partners made aggregate preferred distributions of $146,000 and $491,000, respectively, to an affiliate of our Manager. As of September 30, 2017, our Manager held 607,789 shares of unvested restricted class A common stock, which had an aggregate grant date fair value of $17.8 million. The shares vest in installments over three years from the date of issuance. During the three and nine months ended September 30, 2017, we recorded non-cash expense related to shares held by our Manager of $2.9 million and $8.7 million, respectively, compared to $2.5 million and $7.1 million during the same periods of 2016. We did not issue any shares of restricted class A common stock to our Manager during the nine months ended September 30, 2017 or 2016, respectively. Refer to Note 14 for further details on our restricted class A common stock. During the nine months ended September 30, 2017 and 2016, we originated five loans and one loan, respectively, whereby each respective borrower engaged an affiliate of our Manager to act as title insurance agent in connection with each transaction. We did not incur any expenses or receive any revenues as a result of these transactions. During the three and nine months ended September 30, 2017, we incurred $87,000 and $254,000, respectively, of expenses for various administrative and capital market data services to third-party service providers that are affiliates of our Manager, compared to $112,000 and $282,000 during the same periods of 2016. On June 30, 2017, in a fully subscribed offering totaling $474.6 million, certain Blackstone-advised investment vehicles purchased, in the aggregate, $72.9 million of securitized debt obligations issued by the Securitization. These investments by the Blackstone-advised investment vehicles represented no more than a 49% participation in any individual tranche and were purchased by the Blackstone-advised investment vehicles from third-party investment banks on market terms negotiated by the majority third-party investors. Refer to Note 8 for further details on the Securitization.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	18. COMMITMENTS AND CONTINGENCIES Unfunded Commitments Under Loans Receivable As of September 30, 2017, we had unfunded commitments of $1.6 billion related to 67 of our loans receivable, which amounts will generally be funded to finance lease-related or capital expenditures by our borrowers. These future commitments will expire variously over the next four years. Litigation From time to time, we may be involved in various claims and legal actions arising in the ordinary course of business. As of September 30, 2017, we were not involved in any material legal proceedings. Board of Directors’ Compensation In April 2017, our board of directors approved changes to the compensation of our five independent directors which were effective as of the beginning of the third quarter of 2017. The other three board members, including our chairman and our chief executive officer, will continue to serve as directors without compensation for such service. These changes increased the annual compensation of our directors from $125,000 to $175,000 and are paid $75,000 in cash and $100,000 in the form of deferred stock units. In addition, (i) the chair of our audit committee received an increase in the additional annual cash compensation from $12,000 to $20,000, (ii) the other members of our audit committee received additional annual cash compensation of $10,000, and (iii) the chairs of each of our compensation and corporate governance committees received additional annual cash compensation of $10,000.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include, on a consolidated basis, our accounts, the accounts of our wholly-owned subsidiaries, majority-owned subsidiaries, and variable interest entities, or VIEs, of which we are the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation.
Principles of Consolidation	Principles of Consolidation We consolidate all entities that we control through either majority ownership or voting rights. In addition, we consolidate all VIEs of which we are considered the primary beneficiary. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest and/or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary and is generally the entity with (i) the power to direct the activities that most significantly affect the VIE’s economic performance and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. Refer to Note 16 for additional discussion of our consolidated VIE. In April 2017, we entered into a joint venture, or our Multifamily Joint Venture, with Walker & Dunlop Inc. to originate, hold, and finance multifamily bridge loans. Pursuant to the terms of the agreements governing the joint venture, Walker & Dunlop contributed 15% of the venture’s equity capital and we contributed 85%. We consolidate the Multifamily Joint Venture as we have a controlling financial interest. The non-controlling interests included on our consolidated balance sheets represent the equity interests in our Multifamily Joint Venture that are owned by Walker & Dunlop. A portion of our Multifamily Joint Venture’s consolidated equity and results of operations are allocated to these non-controlling interests based on Walker & Dunlop’s pro-rata ownership of our Multifamily Joint Venture.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results may ultimately differ from those estimates.
Revenue Recognition	Revenue Recognition Interest income from our loans receivable portfolio is recognized over the life of each investment using the effective interest method and is recorded on the accrual basis. Recognition of fees, premiums, and discounts associated with these investments is deferred until the loan is advanced and is then recorded over the term of the loan as an adjustment to yield. Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful. Income is then recorded on the basis of cash received until accrual is resumed when the loan becomes contractually current and performance is demonstrated to be resumed. In addition, for loans we originate, the related origination expenses are deferred and recognized as a component of interest income; however, expenses related to loans we acquire are included in general and administrative expenses as incurred.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents represent cash held in banks, cash on hand, and liquid investments with original maturities of three months or less. We may have bank balances in excess of federally insured amounts; however, we deposit our cash and cash equivalents with high credit-quality institutions to minimize credit risk exposure. We have not experienced, and do not expect, any losses on our cash or cash equivalents. Restricted cash represents cash held in a segregated bank account related to a letter of credit. The following table provides a reconciliation of cash, cash equivalents, and restricted cash in our consolidated balance sheets to the total amount shown in our consolidated statements of cash flows ($ in thousands): September 30, 2017 September 30, 2016 Cash and cash equivalents $ 61,221 $ 94,061 Restricted cash 32,864 877 Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows $ 94,085 $ 94,938
Loans Receivable and Provision for Loan Losses	Loans Receivable and Provision for Loan Losses We originate and purchase commercial real estate debt and related instruments generally to be held as long-term investments at amortized cost. We are required to periodically evaluate each of these loans for possible impairment. Impairment is indicated when it is deemed probable that we will not be able to collect all amounts due to us pursuant to the contractual terms of the loan. If a loan is determined to be impaired, we write down the loan through a charge to the provision for loan losses. Impairment of these loans, which are collateral dependent, is measured by comparing the estimated fair value of the underlying collateral, less costs to sell, to the book value of the respective loan. These valuations require significant judgments, which include assumptions regarding capitalization rates, leasing, creditworthiness of major tenants, occupancy rates, availability of financing, exit plan, loan sponsorship, actions of other lenders, and other factors deemed necessary by our Manager. Actual losses, if any, could ultimately differ from these estimates. Our Manager performs a quarterly review of our portfolio of loans. In conjunction with this review, our Manager assesses the risk factors of each loan, and assigns a risk rating based on a variety of factors, including, without limitation, loan-to-value ratio, or LTV, debt yield, property type, geographic and local market dynamics, physical condition, cash flow volatility, leasing and tenant profile, loan structure and exit plan, and project sponsorship. Based on a 5-point scale, our loans are rated “1” through “5,” from less risk to greater risk, which ratings are defined as follows: 1 - Very Low Risk 2 - Low Risk 3 - Medium Risk 4 - High Risk/Potential for Loss: 5 - Impaired/Loss Likely: During the second quarter of 2015, we acquired a portfolio of loans from General Electric Capital Corporation and certain of its affiliates, or the GE portfolio, for a total purchase price of $4.7 billion. We allocated the aggregate purchase price between each loan based on its fair value relative to the overall portfolio, which allocation resulted in purchase discounts or premiums determined on an asset-by-asset basis. Each loan accretes from its allocated purchase price to its expected collection value over the life of the loan, consistent with the other loans in our portfolio.
Equity Investment in Unconsolidated Subsidiary	Equity Investment in Unconsolidated Subsidiary Our carried interest in CT Opportunity Partners I, LP, or CTOPI, was accounted for using the equity method. CTOPI’s assets and liabilities were not consolidated into our financial statements due to our determination that (i) it was not a VIE and (ii) the other investors in CTOPI had sufficient rights to preclude consolidation by us. As such, we reported our allocable percentage of the net assets of CTOPI on our consolidated balance sheets. The investment was fully realized as of December 31, 2016 and we no longer have any equity investments in unconsolidated subsidiaries in our consolidated financial statements.
Derivative Financial Instruments	Derivative Financial Instruments We classify all derivative financial instruments as either other assets or other liabilities on our consolidated balance sheets at fair value. On the date we enter into a derivative contract, we designate each contract as (i) a hedge of a net investment in a foreign operation, or net investment hedge, (ii) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability, or cash flow hedge, (iii) a hedge of a recognized asset or liability, or fair value hedge, or (iv) a derivative instrument not to be designated as a hedging derivative, or non-designated hedge. For all derivatives other than those designated as non-designated hedges, we formally document our hedge relationships and designation at the contract’s inception. This documentation includes the identification of the hedging instruments and the hedged items, its risk management objectives, strategy for undertaking the hedge transaction and our evaluation of the effectiveness of its hedged transaction. On a quarterly basis, we also formally assess whether the derivative we designated in each hedging relationship is expected to be, and has been, highly effective in offsetting changes in the value or cash flows of the hedged items. If it is determined that a derivative is not highly effective at hedging the designated exposure, hedge accounting is discontinued and the changes in fair value of the instrument are included in net income prospectively. Changes in the fair value of our derivative instruments that qualify as hedges are reported as a component of accumulated other comprehensive income (loss) on our consolidated financial statements. Deferred gains and losses are reclassified out of accumulated other comprehensive income (loss) and into net income in the same period or periods during which the hedged transaction affects earnings, and are presented in the same line item as the earnings effect of the hedged item. For cash flow hedges, this is typically when the periodic swap settlements are made, while for net investment hedges, this occurs when the hedged item is sold or substantially liquidated. To the extent a derivative does not qualify for hedge accounting and is deemed a non-designated hedge, the changes in its fair value are included in net income concurrently.
Secured Debt Agreements	Secured Debt Agreements Where applicable, we record investments financed with repurchase agreements as separate assets and the related borrowings under any repurchase agreements are recorded as separate liabilities on our consolidated balance sheets. Interest income earned on the investments and interest expense incurred on the repurchase agreements are reported separately on our consolidated statements of operations.
Senior Loan Participations	Senior Loan Participations In certain instances, we finance our loans through the non-recourse syndication of a senior loan interest to a third-party. Depending on the particular structure of the syndication, the senior loan interest may remain on our GAAP balance sheet or, in other cases, the sale will be recognized and the senior loan interest will no longer be included in our consolidated financial statements. When these sales are not recognized under GAAP we reflect the transaction by recording a loan participations sold liability on our consolidated balance sheet, however this gross presentation does not impact stockholders’ equity or net income. When the sales are recognized, our balance sheet only includes our remaining subordinate loan and not the non-consolidated senior interest we sold.
Convertible Notes	Convertible Notes The “Debt with Conversion and Other Options” Topic of the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, requires the liability and equity components of convertible debt instruments that may be settled in cash upon conversion, including partial cash settlement, to be separately accounted for in a manner that reflects the issuer’s nonconvertible debt borrowing rate. The initial proceeds from the sale of convertible notes are allocated between a liability component and an equity component in a manner that reflects interest expense at the rate of similar nonconvertible debt that could have been issued at such time. The equity component represents the excess initial proceeds received over the fair value of the liability component of the notes as of the date of issuance. We measured the estimated fair value of the debt component of our convertible notes as of the respective issuance dates based on our nonconvertible debt borrowing rate. The equity component of each series of our convertible notes is reflected within additional paid-in capital on our consolidated balance sheet, and the resulting debt discount is amortized over the period during which such convertible notes are expected to be outstanding (through the maturity date) as additional non-cash interest expense. The additional non-cash interest expense attributable to such convertible notes will increase in subsequent periods through the maturity date as the notes accrete to their par value over the same period.
Deferred Financing Costs	Deferred Financing Costs The deferred financing costs that are included as a reduction in the net book value of the related liability on our consolidated balance sheets include issuance and other costs related to our debt obligations. These costs are amortized as interest expense using the effective interest method over the life of the related obligations.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The “Fair Value Measurements and Disclosures” Topic, or ASC 820, defines fair value, establishes a framework for measuring fair value, and requires certain disclosures about fair value measurements under GAAP. Specifically, this guidance defines fair value based on exit price, or the price that would be received upon the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date. ASC 820 also establishes a fair value hierarchy that prioritizes and ranks the level of market price observability used in measuring financial instruments. Market price observability is affected by a number of factors, including the type of financial instrument, the characteristics specific to the financial instrument, and the state of the marketplace, including the existence and transparency of transactions between market participants. Financial instruments with readily available quoted prices in active markets generally will have a higher degree of market price observability and a lesser degree of judgment used in measuring fair value. Financial instruments measured and reported at fair value are classified and disclosed based on the observability of inputs used in the determination, as follows: • Level 1: Generally includes only unadjusted quoted prices that are available in active markets for identical financial instruments as of the reporting date. • Level 2: Pricing inputs include quoted prices in active markets for similar instruments, quoted prices in less active or inactive markets for identical or similar instruments where multiple price quotes can be obtained, and other observable inputs, such as interest rates, yield curves, credit risks, and default rates. • Level 3: Pricing inputs are unobservable for the financial instruments and include situations where there is little, if any, market activity for the financial instrument. These inputs require significant judgment or estimation by management of third-parties when determining fair value and generally represent anything that does not meet the criteria of Levels 1 and 2. The estimated value of each asset reported at fair value using Level 3 inputs is determined by an internal committee composed of members of senior management of our Manager, including our Chief Executive Officer, Chief Financial Officer, and other senior officers. Certain of our other assets are reported at fair value either (i) on a recurring basis, as of each quarter-end, or (ii) on a nonrecurring basis, as a result of impairment or other events. Our assets that are recorded at fair value are discussed further in Note 15. We generally value our assets recorded at fair value by either (i) discounting expected cash flows based on assumptions regarding the collection of principal and interest and estimated market rates, or (ii) obtaining assessments from third-party dealers. For collateral-dependent loans that are identified as impaired, we measure impairment by comparing our Manager’s estimation of the fair value of the underlying collateral, less costs to sell, to the book value of the respective loan. These valuations may require significant judgments, which include assumptions regarding capitalization rates, leasing, creditworthiness of major tenants, occupancy rates, availability of financing, exit plan, loan sponsorship, actions of other lenders, and other factors deemed necessary by our Manager. We are also required by GAAP to disclose fair value information about financial instruments, that are not otherwise reported at fair value in our consolidated balance sheet, to the extent it is practicable to estimate a fair value for those instruments. These disclosure requirements exclude certain financial instruments and all non-financial instruments. The following methods and assumptions are used to estimate the fair value of each class of financial instruments, for which it is practicable to estimate that value: • Cash and cash equivalents: The carrying amount of cash and cash equivalents approximates fair value. • Restricted cash: The carrying amount of restricted cash approximates fair value. • Loans receivable, net: The fair values of these loans were estimated by our Manager based on a discounted cash flow methodology, taking into consideration various factors including capitalization rates, discount rates, leasing, occupancy rates, availability and cost of financing, exit plan, sponsorship, actions of other lenders, and indications of market value from other market participants. • Derivative financial instruments: The fair value of our foreign currency and interest rate contracts was estimated using advice from a third-party derivative specialist, based on contractual cash flows and observable inputs comprising foreign currency rates and credit spreads. • Secured debt agreements, net: The fair value of these instruments was estimated based on the rate at which a similar credit facility would currently be priced. • Loan participations sold, net: The fair value of these instruments was estimated based on the value of the related loan receivable asset. • Securitized debt obligations, net: The fair value of these instruments was estimated by utilizing third-party pricing service providers. In determining the value of a particular investment, pricing service providers may use broker-dealer quotations, reported trades, or valuation estimates from their internal pricing models to determine the reported price. • Convertible notes, net: Each series of the convertible notes is actively traded and their fair values were obtained using quoted market prices.
Income Taxes	Income Taxes Our financial results generally do not reflect provisions for current or deferred income taxes on our REIT taxable income. We believe that we operate in a manner that will continue to allow us to be taxed as a REIT and, as a result, we generally do not expect to pay substantial corporate level taxes other than those payable by our taxable REIT subsidiaries. If we were to fail to meet these requirements, we may be subject to federal, state, and local income tax on current and past income, and penalties. Refer to Note 13 for additional information.
Stock-Based Compensation	Stock-Based Compensation Our stock-based compensation consists of awards issued to our Manager and certain individuals employed by an affiliate of our Manager that vest over the life of the awards, as well as deferred stock units issued to certain members of our Board of Directors. Stock-based compensation expense is recognized for these awards in net income on a variable basis over the applicable vesting period of the awards, based on the value of our class A common stock. Refer to Note 14 for additional information.
Earnings per Share	Earnings per Share Basic earnings per share, or Basic EPS, is computed in accordance with the two-class method and is based on the net earnings allocable to our class A common stock, including restricted class A common stock and deferred stock units, divided by the weighted-average number of shares of our class A common stock, including restricted class A common stock and deferred stock units outstanding during the period. Our restricted class A common stock is considered a participating security, as defined by GAAP, and has been included in our Basic EPS under the two-class method as these restricted shares have the same rights as our other shares of class A common stock, including participating in any gains or losses. Diluted earnings per share, or Diluted EPS, is determined using the treasury stock method, and is based on the net earnings allocable to our class A common stock, including restricted class A common stock and deferred stock units, divided by the weighted-average number of shares of our class A common stock, including restricted class A common stock and deferred stock units. Refer to Note 11 for additional discussion of earnings per share.
Foreign Currency	Foreign Currency In the normal course of business, we enter into transactions not denominated in United States, or U.S., dollars. Foreign exchange gains and losses arising on such transactions are recorded as a gain or loss in our consolidated statements of operations. In addition, we consolidate entities that have a non-U.S. dollar functional currency. Non-U.S. dollar denominated assets and liabilities are translated to U.S. dollars at the exchange rate prevailing at the reporting date and income, expenses, gains, and losses are translated at the average exchange rate over the applicable period. Cumulative translation adjustments arising from the translation of non-U.S. dollar denominated subsidiaries are recorded in other comprehensive income (loss).
Underwriting Commissions and Offering Costs	Underwriting Commissions and Offering Costs Underwriting commissions and offering costs incurred in connection with common stock offerings are reflected as a reduction of additional paid-in capital. Costs incurred that are not directly associated with the completion of a common stock offering are expensed when incurred.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2017, the FASB issued ASU 2017-12 “Derivatives and Hedging Topic 815: Targeted Improvements to Accounting for Hedging Activities,” or ASU 2017-12. ASU 2017-12 is intended to better align an entity’s financial reporting for hedging activities with the economic objectives of those activities. Upon adoption of ASU 2017-12, the cumulative ineffectiveness that has previously been recognized on existing cash flow and net investment hedges will be adjusted and removed from beginning retained earnings and placed in accumulated other comprehensive income (loss). We adopted ASU 2017-12 in the third quarter of 2017, which did not have an impact on our financial statements as we had not previously recognized any hedge ineffectiveness related to our existing cash flow and net investment hedges. In future periods, for hedges that are deemed effective, we will no longer need to bifurcate hedges into an effective and ineffective portion, and all gains or losses on effective hedges will be recognized in other comprehensive income (loss). In November 2016, the FASB issued ASU 2016-18 “Statement of Cash Flows (Topic 230): Restricted Cash,” or ASU 2016-18. ASU 2016-18 is intended to clarify how entities present restricted cash in the statement of cash flows. The guidance requires entities to show the changes in the total of cash and cash equivalents and restricted cash in the statement of cash flows. As a result, entities will no longer present transfers between cash and cash equivalents and restricted cash in the statement of cash flows. We adopted ASU 2016-18 in the second quarter of 2017 and applied the guidance retrospectively to our prior period consolidated statement of cash flows. In June 2016, the FASB issued ASU 2016-13 “Financial Instruments – Credit Losses – Measurement of Credit Losses on Financial Instruments (Topic 326),” or ASU 2016-13. ASU 2016-13 significantly changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. ASU 2016-13 will replace the “incurred loss” model under existing guidance with an “expected loss” model for instruments measured at amortized cost, and require entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do today under the other-than-temporary impairment model. It also simplifies the accounting model for purchased credit-impaired debt securities and loans. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019 and is to be adopted through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. While we are currently evaluating the impact ASU 2016-13 will have on our consolidated financial statements, we expect that the adoption will result in an increased amount of provisions for potential loan losses as well as the recognition of such provisions earlier in the lending cycle. We currently do not have any provision for loan losses on our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606) ,

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash in our consolidated balance sheets to the total amount shown in our consolidated statements of cash flows ($ in thousands): September 30, 2017 September 30, 2016 Cash and cash equivalents $ 61,221 $ 94,061 Restricted cash 32,864 877 Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows $ 94,085 $ 94,938

Loans Receivable, Net (Tables)

Loans Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Overall Statistics for Loans Receivable Portfolio	The following table details overall statistics for our loans receivable portfolio ($ in thousands): September 30, 2017 December 31, 2016 Number of loans 111 107 Principal balance $ 9,681,055 $ 8,727,218 Net book value $ 9,637,152 $ 8,692,978 Unfunded loan commitments (1) $ 1,622,216 $ 882,472 Weighted-average cash coupon (2) 5.30 % 5.01 % Weighted-average all-in yield (2) 5.68 % 5.36 % Weighted-average maximum maturity (years) (3) 3.4 3.2 (1) Unfunded commitments will primarily be funded to finance property improvements or lease-related expenditures by the borrowers. These future commitments will be funded over the term of each loan, subject in certain cases to an expiration date. (2) As of September 30, 2017, our floating rate loans were indexed to various benchmark rates, with 91% of floating rate loans by principal balance indexed to USD LIBOR. In addition, $273.9 million of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 1.24%, as of September 30, 2017. As of December 31, 2016, our floating rate loans were indexed to various benchmark rates, with 84% of floating rate loans indexed to USD LIBOR. In addition, $216.3 million of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 1.27%, as of December 31, 2016. In addition to cash coupon, all-in yield includes the amortization of deferred origination and extension fees, loan origination costs, purchase discounts, and accrual of exit fees. Cash coupon and all-in yield assume applicable floating benchmark rates for weighted-average calculation. (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of September 30, 2017, 72% of our loans by principal balance were subject to yield maintenance or other prepayment restrictions and 28% were open to repayment by the borrower without penalty. As of December 31, 2016, 64% of our loans were subject to yield maintenance or other prepayment restrictions and 36% were open to repayment by the borrower without penalty.
Activity Relating to Loans Receivable Portfolio	Activity relating to our loans receivable portfolio was as follows ($ in thousands): Principal Deferred Fees / (1) Net Book Value December 31, 2016 $ 8,727,218 $ (34,240) $ 8,692,978 Loan fundings 2,789,341 — 2,789,341 Loan repayments (1,970,743 ) — (1,970,743 ) Unrealized gain (loss) on foreign currency translation 135,239 (116 ) 135,123 Deferred fees and other items — (38,434 ) (38,434 ) Amortization of fees and other items — 28,887 28,887 September 30, 2017 $ 9,681,055 $ (43,903 ) $ 9,637,152 (1) Other items primarily consist of purchase discounts or premiums, exit fees, and deferred origination expenses.
Property Type and Geographic Distribution of Properties Securing Loans in Portfolio	The tables below detail the property type and geographic distribution of the properties securing the loans in our portfolio ($ in thousands): September 30, 2017 Property Type Number of Net Book Total Loan (1) Percentage of Office 55 $ 5,781,675 $ 5,814,214 54% Hotel 14 1,713,162 1,784,893 17 Retail 7 539,752 982,270 9 Multifamily 17 762,969 767,875 7 Condominium 2 129,421 273,112 3 Manufactured housing 7 232,148 231,856 2 Other 9 478,025 814,457 8 111 $ 9,637,152 $ 10,668,677 100% Geographic Location Number of Net Book Total Loan (1) Percentage of United States Northeast 26 $ 2,680,546 $ 2,694,018 25% West 28 2,470,097 2,629,456 24 Southeast 21 1,964,534 2,414,994 23 Midwest 8 890,546 894,564 8 Southwest 8 291,792 290,393 3 Northwest 2 249,118 251,422 2 Subtotal 93 8,546,633 9,174,847 85 International United Kingdom 7 486,794 838,763 8 Canada 7 462,832 458,619 4 Belgium 1 72,544 73,247 1 Germany 1 12,114 66,810 1 Netherlands 2 56,235 56,391 1 Subtotal 18 1,090,519 1,493,830 15 Total 111 $ 9,637,152 $ 10,668,677 100% (1) In certain instances, we finance our loans through the non-recourse sale of a senior loan interest that is not included in our consolidated financial statements. See Note 2 for further discussion. Total loan exposure encompasses the entire loan we originated and financed, including $987.6 million of such non-consolidated senior interests as of September 30, 2017. December 31, 2016 Property Type Number of Net Book Total Loan (1) Percentage of Office 55 $ 4,800,609 $ 4,889,456 50% Hotel 18 1,889,732 1,957,334 20 Retail 9 769,813 1,173,592 12 Multifamily 8 521,097 523,529 5 Manufactured housing 9 296,290 296,252 3 Condominium 2 66,070 258,360 3 Other 6 349,367 658,211 7 107 $ 8,692,978 $ 9,756,734 100% Geographic Location Number of Net Book Total Loan (1) Percentage of United States Northeast 26 $ 2,548,257 $ 2,562,149 26% Southeast 21 1,492,530 1,899,748 19 West 22 1,628,811 1,828,667 19 Midwest 7 695,713 698,093 7 Southwest 8 380,639 379,766 4 Northwest 3 227,747 293,564 3 Subtotal 87 6,973,697 7,661,987 78 International United Kingdom 9 977,136 1,305,816 13 Canada 8 487,835 483,923 5 Germany 1 204,241 254,644 3 Netherlands 2 50,069 50,364 1 Subtotal 20 1,719,281 2,094,747 22 Total 107 $ 8,692,978 $ 9,756,734 100% (1) In certain instances, we finance our loans through the non-recourse sale of a senior loan interest that is not included in our consolidated financial statements. See Note 2 for further discussion. Total loan exposure encompasses the entire loan we originated and financed, including $1.0 billion of such non-consolidated senior interests as of December 31, 2016.
Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings	The following table allocates the principal balance and net book value of our loans receivable based on our internal risk ratings ($ in thousands): September 30, 2017 December 31, 2016 Risk Rating Number of Loans Net Book Value Total Loan Exposure (1) Risk Rating Number of Loans Net Book Value Total Loan Exposure (1) 1 4 $ 421,313 $ 421,628 1 8 $ 361,100 $ 361,574 2 49 3,701,801 3,708,603 2 52 4,011,992 4,083,678 3 57 5,493,409 6,517,829 3 46 4,299,026 5,290,668 4 1 20,629 20,617 4 1 20,860 20,814 5 — — — 5 — — — 111 $ 9,637,152 $ 10,668,677 107 $ 8,692,978 $ 9,756,734 (1) In certain instances, we finance our loans through the non-recourse sale of a senior loan interest that is not included in our consolidated financial statements. See Note 2 for further discussion. Total loan exposure encompasses the entire loan we originated and financed, including $987.6 million and $1.0 billion of such non-consolidated senior interests as of September 30, 2017 and December 31, 2016, respectively.

Other Assets and Liabilities (T

Other Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Summary of Components of Other Assets	The following table details the components of our other assets ($ in thousands): September 30, 2017 December 31, 2016 Accrued interest receivable $ 34,715 $ 32,871 Collateral deposited under derivative agreements 7,750 79 Derivative assets 1,628 4,086 Loan portfolio payments held by servicer (1) 845 5,765 Prepaid expenses 469 803 Prepaid taxes 34 16 Other 239 450 Total $ 45,680 $ 44,070 (1) Represents loan principal and interest payments held by our third-party loan servicer as of the balance sheet date which were remitted to us during the subsequent remittance cycle.
Summary of Components of Other Liabilities	The following table details the components of our other liabilities ($ in thousands): September 30, 2017 December 31, 2016 Accrued dividends payable $ 58,793 $ 58,615 Accrued interest payable 19,922 9,049 Accrued management and incentive fees payable 13,243 12,798 Derivative liabilities 7,167 210 Accounts payable and other liabilities 2,633 1,775 Secured debt repayments pending servicer remittance (1) — 5,372 Total $ 101,758 $ 87,819 (1) Represents pending transfers from our third-party loan servicer that were remitted to our banking counterparties during the subsequent remittance cycle.

Secured Debt Agreements, Net (T

Secured Debt Agreements, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Secured Debt Agreements	The following table details our secured debt agreements ($ in thousands): Secured Debt Agreements Borrowings Outstanding September 30, 2017 December 31, 2016 Credit facilities $ 4,386,645 $ 3,572,837 GE portfolio acquisition facility 1,090,946 1,479,582 Asset-specific financings 517,256 679,207 Revolving credit agreement 101,750 — Total secured debt agreements $ 6,096,597 $ 5,731,626 Deferred financing costs (1) (17,462 ) (15,272 ) Net book value of secured debt $ 6,079,135 $ 5,716,354 (1) Costs incurred in connection with our secured debt agreements are recorded on our consolidated balance sheet when incurred and recognized as a component of interest expense over the life of each related agreement.
Credit Facilities	The following tables detail our credit facilities ($ in thousands): September 30, 2017 Maximum Collateral Credit Borrowings Lender Facility Size (1) Assets (2) Potential (3) Outstanding Available (3) Wells Fargo $ 2,000,000 $ 2,232,117 $ 1,724,227 $ 1,398,224 $ 326,003 MetLife 1,000,000 1,030,148 807,164 807,164 — Bank of America 750,000 818,359 641,066 641,066 — Citibank (4) 795,350 596,119 464,849 356,751 108,098 JP Morgan (5) 500,000 453,121 344,656 295,984 48,672 Deutsche Bank 500,000 393,564 295,743 295,743 — Société Générale (6) 472,560 332,761 266,000 266,000 — Morgan Stanley (7) 669,900 422,332 331,037 211,105 119,932 Bank of America - Multi. JV (8) 200,000 87,000 69,600 69,600 — Goldman Sachs - Multi. JV (8) 250,000 59,125 45,008 45,008 — $ 7,137,810 $ 6,424,646 $ 4,989,350 $ 4,386,645 $ 602,705 December 31, 2016 Maximum Collateral Credit Borrowings Lender Facility Size (1) Assets (2) Potential (3) Outstanding Available (3) Wells Fargo $ 2,000,000 $ 1,718,874 $ 1,339,942 $ 1,107,733 $ 232,209 MetLife 1,000,000 1,106,017 862,454 862,454 — Bank of America 750,000 794,881 617,694 617,694 — JP Morgan (5) 500,000 550,560 420,414 316,219 104,195 Morgan Stanley (7) 308,500 344,056 272,221 231,930 40,291 Citibank (4) 500,000 508,989 394,677 229,629 165,048 Société Générale (6) 420,680 274,351 207,178 207,178 — $ 5,479,180 $ 5,297,728 $ 4,114,580 $ 3,572,837 $ 541,743 (1) Maximum facility size represents the largest amount of borrowings available under a given facility once sufficient collateral assets have been approved by the lender and pledged by us. (2) Represents the principal balance of the collateral assets. (3) Potential borrowings represents the total amount we could draw under each facility based on collateral already approved and pledged. When undrawn, these amounts are immediately available to us at our sole discretion under the terms of each credit facility. (4) As of September 30, 2017, the Citibank maximum facility size was composed of a general $500.0 million facility size denominated in U.S. Dollars plus a general €250.0 million ($295.4 million) facility size that contemplated British Pound Sterling and Euro borrowings. As of December 31, 2016, the maximum facility size was composed of a general $500.0 million facility. (5) As of September 30, 2017 and December 31, 2016, the JP Morgan maximum facility size was composed of a general $500.0 million facility size, under which U.S. Dollars and British Pound Sterling borrowings are contemplated. (6) As of September 30, 2017 and December 31, 2016, the Société Générale maximum facility size was composed of a €400.0 million facility size that was translated to $472.6 million and $420.7 million, respectively. Borrowings denominated in U.S. Dollars, British Pound Sterling, and Euro are contemplated under this facility. (7) As of September 30, 2017, the Morgan Stanley maximum facility size was composed of a £500.0 million facility size that was translated to $669.9 million. As of December 31, 2016, the maximum facility size was composed of a £250.0 million facility size that was translated to $308.5 million. Borrowings denominated in U.S. Dollars, British Pound Sterling, and Euro are contemplated under this facility. (8) These facilities finance the loan investments of our consolidated Multifamily Joint Venture. Refer to Note 2 for additional discussion of our Multifamily Joint Venture.
Summary of Key Terms of Credit Facilities	The following tables outline the key terms of our credit facilities as of September 30, 2017: Lender Currency Guarantee (1) Margin Call (2) Term/Maturity Wells Fargo $ 25% Collateral marks only Term matched (3) MetLife $ 50% Collateral marks only April 21, 2023 (4) Bank of America $ 50% Collateral marks only May 21, 2021 (5) Société Générale $ / £ / € 25% Collateral marks only Term matched (3) Deutsche Bank $ 35% Collateral marks only Term matched (3) Citibank $ / £ / € 25% Collateral marks only Term matched (3) Morgan Stanley $ / £ / € 25% Collateral marks only March 3, 2020 JP Morgan $ / £ 50% Collateral marks only January 7, 2020 Bank of America - Multi. JV (6) $ 43% Collateral marks only July 19, 2021 Goldman Sachs - Multi. JV (6) $ 25% Collateral marks only July 12, 2020 (1) Other than amounts guaranteed based on specific collateral asset types, borrowings under our credit facilities are non-recourse to us. (2) Margin call provisions under our credit facilities do not permit valuation adjustments based on capital markets events, and are limited to collateral-specific credit marks. (3) These credit facilities have various availability periods during which new advances can be made and which are generally subject to each lender’s discretion. Maturity dates for advances outstanding are tied to the term of each respective collateral asset. (4) Includes five one-year extension options which may be exercised at our sole discretion. (5) Includes two one-year extension options which may be exercised at our sole discretion. (6) These facilities finance the loan investments of our consolidated Multifamily Joint Venture. Refer to Note 2 for additional discussion of our Multifamily Joint Venture. Currency Outstanding Potential (1) Index Rate (2) Advance (3) $ $ 4,123,064 $ 4,610,777 1-month USD LIBOR L+1.86% 78.8% € € 66,186 € 87,786 3-month EURIBOR L+2.24% 80.0% £ £ 138,371 £ 205,152 3-month GBP LIBOR L+2.24% 78.6% $ 4,386,645 $ 4,989,350 L+1.88% 78.8% (1) Potential borrowings represents the total amount we could draw under each facility based on collateral already approved and pledged. When undrawn, these amounts are immediately available to us at our sole discretion under the terms of each credit facility. (2) Represents weighted-average cash coupon based on borrowings outstanding. (3) Represents weighted-average advance rate based on the outstanding principal balance of the collateral assets pledged.
Summary of Asset-Specific Financings	The following tables detail our asset-specific financings ($ in thousands): September 30, 2017 Asset-Specific Financings Count Principal Book Value Wtd. Avg. (1) Guarantee (2) Wtd. Avg. (3) Collateral assets 5 $ 662,223 $ 659,152 L+4.70 % n/a Dec. 2020 Financing provided (4) 5 $ 517,256 $ 516,537 L+2.48 % $ 162,517 Dec. 2020 (1) These floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) Other than amounts guaranteed on an asset-by-asset basis, borrowings under our asset-specific financings are non-recourse to us. (3) The weighted-average term is determined based on the maximum maturity of the corresponding loans, assuming all extension options are exercised by the borrower. Each of our asset-specific financings are term-matched to the corresponding collateral loans. (4) Borrowings of $394.8 million under these asset specific financings are cross collateralized with related credit facilities with the same lenders. December 31, 2016 Asset-Specific Financings Count Principal Book Value Wtd. Avg. (1) Guarantee (2) Wtd. Avg. (3) Collateral assets 7 $ 876,083 $ 869,417 L+4.84 % n/a Aug. 2020 Financing provided (4) 7 $ 679,207 $ 676,333 L+2.60 % $ 231,585 Aug. 2020 (1) These floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) Other than amounts guaranteed on an asset-by-asset basis, borrowings under our asset-specific financings are non-recourse to us. (3) The weighted-average term is determined based on the maximum maturity of the corresponding loans, assuming all extension options are exercised by the borrower. Each of our asset-specific financings are term-matched to the corresponding collateral loans. (4) Borrowings of $392.3 million under these asset specific financings are cross collateralized with related credit facilities with the same lenders.

Loan Participations Sold, Net (

Loan Participations Sold, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Summary of Statistics for Loan Participations Sold	The following tables detail our loan participations sold ($ in thousands): September 30, 2017 Loan Participations Sold Count Principal Book Value Yield/Cost (1) Guarantee (2) Term Total loan 1 $ 93,710 $ 91,498 L+5.96 % n/a Feb. 2022 Senior participation (3) 1 33,193 33,193 L+4.00 % n/a Feb. 2022 December 31, 2016 Loan Participations Sold Count Principal Book Value Yield/Cost (1) Guarantee (2) Term Total loan 1 $ 419,560 $ 416,233 L+4.48 % n/a Dec. 2019 Senior participation (3)(4) 1 349,633 348,077 L+2.72 % $ 29,616 Dec. 2019 (1) Our floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred fees / financing costs. (2) As of September 30, 2017, our loan participation sold was non-recourse to us. As of December 31, 2016, our loan participation was subject to a related guarantee agreement for £24.0 million ($29.6 million as of December 31, 2016). (3) During the three and nine months ended September 30, 2017, we recorded $4.0 million and $9.3 million, respectively, of interest expense related to our loan participations sold, of which $2.6 million and $7.7 million was paid in cash. During the three and nine months ended September 30, 2016, we recorded $3.4 million and $10.7 million, respectively, of interest expense related to our loan participations sold, of which $3.2 million and $10.3 million was paid in cash. (4) The difference between principal balance and book value of loan participations sold is due to deferred financing costs of $1.6 million as of December 31, 2016.

Securitized Debt Obligations,32

Securitized Debt Obligations, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Schedule of Information on Securitized Debt Obligations	The following table details our securitized debt obligations ($ in thousands): September 30, 2017 Securitized Debt Obligations Count Principal Book Value Yield/Cost (1) Term (2) Total loan 1 $ 644,788 $ 641,262 L+3.60 % June 2023 Securitized debt obligations (3) 1 474,620 474,298 L+1.94 % June 2033 (1) In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) Loan term represents final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitization. (3) During the three and nine months ended September 30, 2017, we recorded $3.8 million of interest expense related to our securitized debt obligations.

Convertible Notes, Net (Tables)

Convertible Notes, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Summary of Outstanding Convertible Senior Notes	As of September 30, 2017, the following convertible senior notes, or Convertible Notes, were outstanding ($ in thousands): Convertible Notes Issuance Face Value Coupon Rate All-in Cost (1) Conversion Rate (2) Maturity November 2013 $ 172,500 5.25 % 5.87 % 36.1380 December 1, 2018 May 2017 402,500 4.38 % 4.85 % 28.0324 May 5, 2022 (1) Includes issuance costs that are amortized through interest expense over the life of the Convertible Notes using the effective interest method. (2) Represents the shares of class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to a conversion price of $27.67 and $35.67 per share of class A common stock, respectively, for the November 2013 and May 2017 convertible notes. As a result of exceeding the cumulative dividend threshold, as defined in the November 2013 convertible notes supplemental indenture, the conversion rate on the November 2013 convertible notes was most recently adjusted on June 28, 2017 from the prior conversion rate of 35.7236 shares of class A common stock per $1,000 principal amount of convertible notes, which was equivalent to a conversion price of $27.99 per share of class A common stock. The cumulative dividend threshold as defined in the May 2017 convertible notes supplemental indenture has not been exceeded as of September 30, 2017.
Summary of Details about Interest Expense	The following table details our interest expense related to the Convertible Notes ($ in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Cash coupon $ 6,247 $ 2,264 $ 12,732 $ 6,792 Discount and issuance cost amortization 1,202 691 2,869 2,038 Total interest expense $ 7,449 $ 2,955 $ 15,601 $ 8,830
Summary of Details of Net Book Value of Convertible Note	The following table details the net book value of our Convertible Notes on our consolidated balance sheets ($ in thousands): September 30, 2017 December 31, 2016 Face value $ 575,000 $ 172,500 Unamortized discount (11,386 ) (5,532 ) Deferred financing costs (873 ) (206 ) Net book value $ 562,741 $ 166,762

Derivative Financial Instrume34

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Outstanding Foreign Exchange Derivatives Designated as Net Investment Hedges of Foreign Currency Risk	The following table details our outstanding foreign exchange derivatives that were designated as net investment hedges of foreign currency risk (notional amount in thousands): September 30, 2017 December 31, 2016 Foreign Currency Derivatives Number of Notional Foreign Currency Derivatives Number of Notional Sell GBP Forward 1 £ 112,700 Sell GBP Forward 2 £ 141,900 Sell CAD Forward 1 C$ 102,000 Sell CAD Forward 2 C$ 122,900 Sell EUR Forward 1 € 44,900
Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk	The following tables detail our outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk (notional amount in thousands): September 30, 2017 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Swaps 4 C$ 108,183 1.0% CDOR 1.7 Interest Rate Caps 9 $ 204,248 2.4% USD LIBOR 1.7 Interest Rate Caps 3 C$ 23,370 2.0% CDOR 0.6 December 31, 2016 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Swaps 4 C$ 108,271 1.0% CDOR 2.4 Interest Rate Caps 21 $ 802,256 2.0% USD LIBOR 0.4 Interest Rate Caps 5 C$ 400,035 2.0% CDOR 0.4 Interest Rate Cap 1 £ 15,142 2.0% GBP LIBOR 0.3
Summary of Non-designated Hedges	The following tables summarize our non-designated hedges (notional amount in thousands): September 30, 2017 Non-designated Hedges Number of Notional Buy USD / Sell GBP Forward 1 £ 35,000 Buy GBP / Sell USD Forward 1 £ 35,000 Buy USD / Sell CAD Forward 1 C$ 15,000 Buy CAD / Sell USD Forward 1 C$ 15,000 Buy GBP / Sell EUR Forward 1 € 12,857 December 31, 2016 Non-designated Hedges Number of Notional Interest Rate Caps 3 $ 256,875 Interest Rate Caps 2 C$ 37,221 Buy GBP / Sell EUR Forward 1 € 12,857
Summary of Fair Value of Derivative Financial Instruments	The following table summarizes the fair value of our derivative financial instruments ($ in thousands): Fair Value of Derivatives in an Asset Position (1) Fair Value of Derivatives in a Liability Position (2) September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Derivatives designated as hedging instruments: Foreign exchange contracts $ — $ 3,268 $ 5,617 $ 210 Interest rate derivatives 1,238 331 — — Total derivatives designated as hedging instruments $ 1,238 $ 3,599 $ 5,617 $ 210 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 390 $ 487 $ 1,550 $ — Interest rate derivatives — — — — Total derivatives not designated as hedging instruments $ 390 $ 487 $ 1,550 $ — Total Derivatives $ 1,628 $ 4,086 $ 7,167 $ 210 (1) Included in other assets in our consolidated balance sheets. (2) Included in other liabilities in our consolidated balance sheets.
Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations	The following table presents the effect of our derivative financial instruments on our consolidated statements of operations ($ in thousands): Amount of Gain (Loss) Recognized in OCI on Derivatives Location of Gain (Loss) Reclassified from OCI into Income Amount of Gain (Loss) Reclassified from Accumulated OCI into Income Derivatives in Hedging Relationships Three Months 2017 Nine Months 2017 Three Months 2017 Nine Months 2017 Net Investment Hedges Foreign exchange contracts (1) $ (8,524 ) $ (21,757 ) Interest Expense $ — $ — Cash Flow Hedges Interest rate derivatives 536 707 Interest Income (Expense) (2) 41 (900 ) Total $ (7,988 ) $ (21,050 ) $ 41 $ (900 ) (1) During the three and nine months ended September 30, 2017, we paid net cash settlements of $8.7 million and $11.8 million, respectively, on our foreign currency forward contracts, compared to receiving $19.2 million and $17.4 million during the same periods in 2016. Those amounts are included as a component of accumulated other comprehensive loss on our consolidated balance sheets. (2) During the three months ended September 30, 2017, we recorded total interest and related income of $146.4 million which included interest income of $41,000 related to our cash flow hedges. During the nine months ended September 30, 2017, we incurred total interest and related expenses of $168.9 million which included $900,000 related to our cash flow hedges.

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units	The following table details the movement in our outstanding shares of class A common stock, including restricted class A common stock and deferred stock units: Nine Months Ended September 30, Common Stock Outstanding (1) 2017 2016 Beginning balance 94,709,290 93,843,847 Issuance of class A common stock (2) 971 812 Issuance of restricted class A common stock, net 286,773 209,798 Issuance of deferred stock units 20,560 20,850 Ending balance 95,017,594 94,075,307 (1) Includes deferred stock units held by members of our board of directors of 189,587 and 162,371 as of September 30, 2017 and 2016, respectively. (2) Consists of 971 and 812 shares issued under our dividend reinvestment program during the nine months ended September 30, 2017 and 2016, respectively.
Schedule of Dividend Activity	The following table details our dividend activity ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Dividends declared per share of common stock $ 0.62 $ 0.62 $ 1.86 $ 1.86 Total dividends declared $ 58,793 $ 58,226 $ 176,374 $ 174,678
Schedule of Basic and Diluted Earnings Per Share, or EPS, Based on Weighted-Average of Both Restricted and Unrestricted Class A Common Stock Outstanding	The following table sets forth the calculation of basic and diluted net income per share of class A common stock based on the weighted-average of both restricted and unrestricted class A common stock outstanding ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Net income (1) $ 57,722 $ 64,794 $ 159,741 $ 184,921 Weighted-average shares outstanding, basic and diluted 95,013,087 94,071,537 95,004,188 94,067,923 Per share amount, basic and diluted $ 0.61 $ 0.69 $ 1.68 $ 1.97 (1) Represents net income attributable to Blackstone Mortgage Trust, Inc.

Other Expenses (Tables)

Other Expenses (Tables)	9 Months Ended
	Sep. 30, 2017
Other Income and Expenses [Abstract]
Schedule of General and Administrative Expenses	General and administrative expenses consisted of the following ($ in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Professional services (1) $ 933 $ 828 $ 2,811 $ 2,474 Operating and other costs (1) 489 305 1,424 1,695 Subtotal 1,422 1,133 4,235 4,169 Non-cash and CT Legacy Portfolio compensation expenses Management incentive awards plan - CTOPI (2) — 938 — 1,106 Management incentive awards plan - CT Legacy Partners (3) — 354 — 1,112 Restricted class A common stock earned 5,819 4,855 17,496 14,190 Director stock-based compensation 125 94 313 282 Subtotal 5,944 6,241 17,809 16,690 Total BXMT expenses 7,366 7,374 22,044 20,859 Other expenses 53 40 175 131 Total general and administrative expenses $ 7,419 $ 7,414 $ 22,219 $ 20,990 (1) During the three and nine months ended September 30, 2017 we recognized an aggregate $112,000 of expenses related to our Multifamily Joint Venture. (2) Represents the portion of CTOPI promote revenue recorded under compensation awards. See Note 4 for further discussion. (3) Represents the amounts recorded under the CT Legacy Partners management incentive awards during the period. See below for discussion of the CT Legacy Partners management incentive awards plan.

Stock-Based Incentive Plans (Ta

Stock-Based Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Movement in Outstanding Shares of Restricted Class A Common Stock and Weighted-Average Grant Date Fair Value Per Share	The following table details the movement in our outstanding shares of restricted class A common stock and the weighted-average grant date fair value per share: Restricted Class A Weighted-Average Balance as of December 31, 2016 1,309,995 $ 28.68 Granted 289,896 30.55 Vested (335,536 ) 27.78 Forfeited (3,123 ) 27.37 Balance as of September 30, 2017 1,261,232 $ 29.35

Fair Values (Tables)

Fair Values (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table summarizes our assets and liabilities measured at fair value on a recurring basis ($ in thousands): September 30, 2017 December 31, 2016 Level 1 Level 2 Level 3 Fair Value Level 1 Level 2 Level 3 Fair Value Assets Derivatives $ — $ 1,628 $ — $ 1,628 $ — $ 4,086 $ — $ 4,086 Liabilities Derivatives $ — $ 7,167 $ — $ 7,167 $ — $ 210 $ — $ 210
Reconciliation of Beginning and Ending Balances of Assets Measured at Fair Value on Recurring Basis Using Level 3 Inputs	The following table reconciles the beginning and ending balances of assets measured at fair value on a recurring basis using Level 3 inputs ($ in thousands): Nine Months Ended September 30, 2017 2016 (1) January 1, $ — $ 12,561 Proceeds from investment realizations — (2,406 ) Transfers out of level 3 (2) — (20,745 ) Adjustments to fair value included in earnings Gain on investments at fair value — 11,790 September 30, $ — $ 1,200 (1) All assets measured at fair value on a recurring basis using Level 3 inputs were included as a component of other assets in the consolidated Balance Sheets. (2) During the second quarter of 2016, $20.7 million of collateralized debt obligations, or CDOs, were transferred out of Level 3 and into Level 1 as a result of a binding agreement to sell the underlying collateral assets of the CDO to an independent third-party. These investments were realized in the third quarter of 2016.
Schedule of Details of Carrying Amount, Face Amount, and Fair Value of Financial Instruments	The following table details the carrying amount, face amount, and fair value of the financial instruments described in Note 2 ($ in thousands): September 30, 2017 December 31, 2016 Carrying Face Fair Carrying Face Fair Amount Amount Value Amount Amount Value Financial assets Cash and cash equivalents $ 61,221 $ 61,221 $ 61,221 $ 75,567 $ 75,567 $ 75,567 Restricted cash 32,864 32,864 32,864 — — — Loans receivable, net 9,637,152 9,681,055 9,685,422 8,692,978 8,727,218 8,733,784 Financial liabilities Secured debt agreements, net 6,079,135 6,096,597 6,096,597 5,716,354 5,731,626 5,731,626 Loan participations sold, net 33,193 33,193 33,193 348,077 349,633 349,633 Securitized debt obligations, net 474,298 474,620 474,655 — — — Convertible notes, net 562,741 575,000 602,503 166,762 172,500 191,763

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Assets and Liabilities of Consolidated Securitization VIE	The following table details the assets and liabilities of our consolidated Securitization VIE ($ in thousands): September 30, 2017 December 31, 2016 Assets: Loans receivable, net $ 500,000 $ — Other assets 763 — Total assets $ 500,763 $ — Liabilities: Securitized debt obligations, net $ 474,298 $ — Other liabilities 604 — Total liabilities $ 474,902 $ —

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Apr. 30, 2017	Jun. 30, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Joint venture capital contribution percentage		85.00%
Income accrual, description	Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful.
Cash and cash equivalents, description	Cash and cash equivalents represent cash held in banks, cash on hand, and liquid investments with original maturities of three months or less.
Expected loss	$ 0
Provision for loan losses	$ 0
Walker and Dunlop [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Joint venture capital contribution percentage		15.00%
General Electrical Capital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase price of Loan Portfolio			$ 4,700,000,000

Summary of Significant Accoun41

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 61,221	$ 75,567	$ 94,061
Restricted cash	32,864		877
Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows	$ 94,085	$ 75,567	$ 94,938	$ 106,005

Loans Receivable, Net - Overall

Loans Receivable, Net - Overall Statistics for Loans Receivable Portfolio (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	111	107
Net book value	$ 9,637,152	$ 8,692,978
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	111	107
Principal balance	$ 9,681,055	$ 8,727,218
Unfunded loan commitments	$ 1,622,216	$ 882,472
Weighted-average maximum maturity (years)	3 years 4 months 24 days	3 years 2 months 12 days
Loans Receivable [Member] | LIBOR [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average cash coupon, rate	5.30%	5.01%
Weighted-average all-in yield, rate	5.68%	5.36%
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 9,637,152	$ 8,692,978

Loans Receivable, Net - Overa43

Loans Receivable, Net - Overall Statistics for Loans Receivable Portfolio (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Floating rate loans	$ 273.9	$ 216.3
Average floor rate	1.24%	1.27%
Percentage of loans subject to yield maintenance, or other prepayment restrictions	72.00%	64.00%
Percentage of loans open to repayment by borrower without penalty	28.00%	36.00%
USD LIBOR [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loans receivable by type	91.00%	84.00%

Loans Receivable, Net - Activit

Loans Receivable, Net - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance			$ 8,692,978
Unrealized gain (loss) on foreign currency translation	$ 16,175	$ (10,128)	43,990	$ (25,472)
Amortization of fees and other items			28,887	$ 31,594
Ending Balance	9,637,152		9,637,152
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance			8,692,978
Loan fundings			2,789,341
Loan repayments			(1,970,743)
Unrealized gain (loss) on foreign currency translation			135,123
Deferred fees and other items			(38,434)
Amortization of fees and other items			28,887
Ending Balance	9,637,152		9,637,152
Deferred Fees/Other Items [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance			(34,240)
Unrealized gain (loss) on foreign currency translation			(116)
Deferred fees and other items			(38,434)
Amortization of fees and other items			28,887
Ending Balance	(43,903)		(43,903)
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance			8,727,218
Loan fundings			2,789,341
Loan repayments			(1,970,743)
Unrealized gain (loss) on foreign currency translation			135,239
Ending Balance	$ 9,681,055		$ 9,681,055

Loans Receivable, Net - Propert

Loans Receivable, Net - Property Type and Geographic Distribution of Properties Securing Loans in Portfolio (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	111	107
Net book value	$ 9,637,152	$ 8,692,978
Total Loan Exposure	$ 10,668,677	$ 9,756,734
Percentage of Portfolio	100.00%	100.00%
Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	55	55
Net book value	$ 5,781,675	$ 4,800,609
Total Loan Exposure	$ 5,814,214	$ 4,889,456
Percentage of Portfolio	54.00%	50.00%
Hotel [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	14	18
Net book value	$ 1,713,162	$ 1,889,732
Total Loan Exposure	$ 1,784,893	$ 1,957,334
Percentage of Portfolio	17.00%	20.00%
Manufactured Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	7	9
Net book value	$ 232,148	$ 296,290
Total Loan Exposure	$ 231,856	$ 296,252
Percentage of Portfolio	2.00%	3.00%
Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	7	9
Net book value	$ 539,752	$ 769,813
Total Loan Exposure	$ 982,270	$ 1,173,592
Percentage of Portfolio	9.00%	12.00%
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	17	8
Net book value	$ 762,969	$ 521,097
Total Loan Exposure	$ 767,875	$ 523,529
Percentage of Portfolio	7.00%	5.00%
Condominium [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	2	2
Net book value	$ 129,421	$ 66,070
Total Loan Exposure	$ 273,112	$ 258,360
Percentage of Portfolio	3.00%	3.00%
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	9	6
Net book value	$ 478,025	$ 349,367
Total Loan Exposure	$ 814,457	$ 658,211
Percentage of Portfolio	8.00%	7.00%
United States Northeast [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	26	26
Net book value	$ 2,680,546	$ 2,548,257
Total Loan Exposure	$ 2,694,018	$ 2,562,149
Percentage of Portfolio	25.00%	26.00%
United States Southeast [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	21	21
Net book value	$ 1,964,534	$ 1,492,530
Total Loan Exposure	$ 2,414,994	$ 1,899,748
Percentage of Portfolio	23.00%	19.00%
United States West [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	28	22
Net book value	$ 2,470,097	$ 1,628,811
Total Loan Exposure	$ 2,629,456	$ 1,828,667
Percentage of Portfolio	24.00%	19.00%
United States Midwest [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	8	7
Net book value	$ 890,546	$ 695,713
Total Loan Exposure	$ 894,564	$ 698,093
Percentage of Portfolio	8.00%	7.00%
United States Southwest [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	8	8
Net book value	$ 291,792	$ 380,639
Total Loan Exposure	$ 290,393	$ 379,766
Percentage of Portfolio	3.00%	4.00%
United States Northwest [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	2	3
Net book value	$ 249,118	$ 227,747
Total Loan Exposure	$ 251,422	$ 293,564
Percentage of Portfolio	2.00%	3.00%
United States [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	93	87
Net book value	$ 8,546,633	$ 6,973,697
Total Loan Exposure	$ 9,174,847	$ 7,661,987
Percentage of Portfolio	85.00%	78.00%
United Kingdom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	7	9
Net book value	$ 486,794	$ 977,136
Total Loan Exposure	$ 838,763	$ 1,305,816
Percentage of Portfolio	8.00%	13.00%
Canada [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	7	8
Net book value	$ 462,832	$ 487,835
Total Loan Exposure	$ 458,619	$ 483,923
Percentage of Portfolio	4.00%	5.00%
Germany [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	1	1
Net book value	$ 12,114	$ 204,241
Total Loan Exposure	$ 66,810	$ 254,644
Percentage of Portfolio	1.00%	3.00%
Netherlands [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	2	2
Net book value	$ 56,235	$ 50,069
Total Loan Exposure	$ 56,391	$ 50,364
Percentage of Portfolio	1.00%	1.00%
International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	18	20
Net book value	$ 1,090,519	$ 1,719,281
Total Loan Exposure	$ 1,493,830	$ 2,094,747
Percentage of Portfolio	15.00%	22.00%
Belgium [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	1
Net book value	$ 72,544
Total Loan Exposure	$ 73,247
Percentage of Portfolio	1.00%

Loans Receivable, Net - Prope46

Loans Receivable, Net - Property Type and Geographic Distribution of Properties Securing Loans in Portfolio (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Total loan exposure including senior interests	$ 987.6	$ 1,000

Loans Receivable, Net - Princip

Loans Receivable, Net - Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	111	107
Net book value	$ 9,637,152	$ 8,692,978
Total Loan Exposure	$ 10,668,677	$ 9,756,734
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	111	107
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 9,637,152	$ 8,692,978
Risk Rating 1 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loan Exposure	$ 421,628	$ 361,574
Risk Rating 1 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	4	8
Risk Rating 1 [Member] | Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 421,313	$ 361,100
Risk Rating 2 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loan Exposure	$ 3,708,603	$ 4,083,678
Risk Rating 2 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	49	52
Risk Rating 2 [Member] | Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 3,701,801	$ 4,011,992
Risk Rating 3 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loan Exposure	$ 6,517,829	$ 5,290,668
Risk Rating 3 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	57	46
Risk Rating 3 [Member] | Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 5,493,409	$ 4,299,026
Risk Rating 4 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loan Exposure	$ 20,617	$ 20,814
Risk Rating 4 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | SecurityLoan	1	1
Risk Rating 4 [Member] | Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 20,629	$ 20,860

Loans Receivable, Net - Princ48

Loans Receivable, Net - Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Total loan exposure including senior interests	$ 987.6	$ 1,000

Loans Receivable, Net - Additio

Loans Receivable, Net - Additional Information (Detail)	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average risk rating on loan exposure	2.6	2.5
Impaired loans	$ 0	$ 0
Loans held	10,668,677,000	9,756,734,000
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held	767,875,000	$ 523,529,000
Joint Venture [Member] | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held	$ 146,100,000

Equity Investment in Unconsol50

Equity Investment in Unconsolidated Subsidiary - Additional Information (Detail) - CT Opportunity Partners I, LP [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jan. 31, 2011
Schedule of Equity Method Investments [Line Items]
Carried interest revenue, percentage of fund's profit		17.70%
Preferred return		9.00%
Return of capital to partners		100.00%
Promote income recognized	$ 2.1		$ 2.2
Percentage of carried interest distributions pool for employees				45.00%
Description of incentive management fee grants to employees vesting schedule		During the nine months ended September 30, 2016, we recognized $1.1 million of expenses under the CTOPI incentive plan. Such amounts were recognized as a component of general and administrative expenses in our consolidated statement of operations.
CTOPI Incentive Plan [Member]
Schedule of Equity Method Investments [Line Items]
Recognized expenses for incentive plan			$ 1.1

Other Assets and Liabilities -

Other Assets and Liabilities - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Accrued interest receivable	$ 34,715		$ 32,871
Collateral deposited under derivative agreements	7,750		79
Derivative assets	1,628	$ 1,628	4,086
Loan portfolio payments held by servicer	845		5,765
Prepaid expenses	469		803
Prepaid taxes	34		16
Other	239		450
Total	$ 45,680		$ 44,070

Other Assets and Liabilities 52

Other Assets and Liabilities - Summary of Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Other Liabilities [Abstract]
Accrued dividends payable	$ 58,793		$ 58,615
Accrued interest payable	19,922		9,049
Accrued management and incentive fees payable	13,243		12,798
Derivative liabilities	7,167	$ 7,167	210
Accounts payable and other liabilities	2,633		1,775
Secured debt repayments pending servicer remittance			5,372
Total	$ 101,758		$ 87,819

Secured Debt Agreements, Net -

Secured Debt Agreements, Net - Schedule of Secured Debt Agreements (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	$ 517,256,000	$ 679,207,000
Secured debt agreements borrowings outstanding	6,096,597,000	5,731,626,000
Deferred financing costs	(17,462,000)	(15,272,000)
Net book value of secured debt	6,079,135,000	5,716,354,000
Credit Facilities [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	4,386,645,000	3,572,837,000
GE Portfolio Acquisition Facility [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	1,090,946,000	1,479,582,000
Asset-Specific Financings [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	517,256,000	$ 679,207,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	$ 101,750,000		$ 0

Secured Debt Agreements, Net 54

Secured Debt Agreements, Net - Additional Information (Detail) € in Millions, £ in Millions	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2015USD ($)ExtensionOptions	Sep. 30, 2017USD ($)Facility	Sep. 30, 2017GBP (£)Facility	Sep. 30, 2017EUR (€)Facility	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)	May 31, 2017USD ($)
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent						1.88%	1.88%	1.88%
Weighted-average advance rate						78.80%	78.80%	78.80%
Secured debt agreements borrowings outstanding	$ 6,079,135,000	$ 6,079,135,000				$ 6,079,135,000				$ 5,716,354,000
Interest expense		67,891,000		$ 45,373,000		168,917,000			$ 139,819,000
Secured debt agreements borrowings outstanding	6,096,597,000	6,096,597,000				6,096,597,000				5,731,626,000
Covenants, minimum tangible net worth	$ 1,900,000,000	$ 1,900,000,000				$ 1,900,000,000
Covenants, percentage of tangible assets on cash proceeds from equity issuances						75.00%	75.00%	75.00%
Covenants, percentage of recourse indebtedness	5.00%	5.00%				5.00%
Maximum [Member]
Debt Instrument [Line Items]
Covenants, indebtedness to total assets, in percent	83.33%	83.33%				83.33%
Minimum [Member]
Debt Instrument [Line Items]
Covenants, EBITDA to fixed charges, in percent						140.00%	140.00%	140.00%
Covenants, minimum cash liquidity amount	$ 10,000,000	$ 10,000,000				$ 10,000,000
Asset-Specific Financings [Member]
Debt Instrument [Line Items]
Weighted-average outstanding balance						596,200,000			557,900,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Weighted-average outstanding balance						23,500,000			19,500,000
Interest expense						1,700,000			915,000
Amortization of deferred fees and expenses						575,000			248,000
Secured debt agreements borrowings outstanding	101,750,000	101,750,000		$ 0		101,750,000			0
Revolving Credit Facility [Member] | Barclays [Member]
Debt Instrument [Line Items]
Maximum Facility Size			$ 250,000,000								$ 125,000,000
First mortgage bridge to term financing maximum period			6 months
GE Portfolio Acquisition Facility [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	1,090,946,000	1,090,946,000				1,090,946,000				1,479,582,000
GE Portfolio Acquisition Facility [Member] | Wells Fargo [Member]
Debt Instrument [Line Items]
Maximum Facility Size	1,200,000,000	1,200,000,000				1,200,000,000
Approximate credit line, outstanding amount	1,100,000,000
Amount available for potential future fundings of loan	129,400,000	129,400,000				$ 129,400,000
GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member]
Debt Instrument [Line Items]
Weighted average rate					80.00%
Maturity date						May 20, 2020	May 20, 2020	May 20, 2020
Borrowings maturity term						The asset-specific borrowings are term matched to the underlying collateral assets with an outside maturity date of May 20, 2020, which may be extended pursuant to two one-year extension options.	The asset-specific borrowings are term matched to the underlying collateral assets with an outside maturity date of May 20, 2020, which may be extended pursuant to two one-year extension options.	The asset-specific borrowings are term matched to the underlying collateral assets with an outside maturity date of May 20, 2020, which may be extended pursuant to two one-year extension options.
Number of extension options | ExtensionOptions					2
Term of maturity date					1 year
GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of guarantee rate					25.00%
Guarantee of outstanding borrowings					$ 250,000,000
GE Portfolio Acquisition Facility [Member] | Weighted-Average All-in Cost of Credit [Member] | Asset Specific Borrowings [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	1,100,000,000	1,100,000,000				$ 1,100,000,000				1,500,000,000
Credit Facilities [Member]
Debt Instrument [Line Items]
Additional credit capacity							£ 250	€ 250
Number of revolving repurchase facilities closed | Facility						2	2	2
Weighted-average outstanding balance						$ 4,000,000,000			$ 2,900,000,000
Aggregate borrowings	4,400,000,000	4,400,000,000				$ 4,400,000,000				$ 3,600,000,000
Weighted-average advance rate						78.80%	78.80%	78.80%		79.10%
Weighted-average initial maturity						1 year 6 months	1 year 6 months	1 year 6 months		1 year 6 months
Maximum Facility Size	7,137,810,000	7,137,810,000				$ 7,137,810,000				$ 5,479,180,000
Amount available for potential future fundings of loan	602,705,000	602,705,000				602,705,000				541,743,000
Secured debt agreements borrowings outstanding	4,386,645,000	4,386,645,000				$ 4,386,645,000				3,572,837,000
Credit Facilities [Member] | Joint Venture [Member] | Multifamily [Member]
Debt Instrument [Line Items]
Number of new credit facility | Facility						2	2	2
Additional credit capacity						$ 450,000,000
Credit Facilities [Member] | Wells Fargo [Member]
Debt Instrument [Line Items]
Maximum Facility Size	2,000,000,000	2,000,000,000				2,000,000,000				2,000,000,000
Amount available for potential future fundings of loan	$ 326,003,000	$ 326,003,000				$ 326,003,000				$ 232,209,000
Borrowings maturity term						Term matched	Term matched	Term matched
Credit Facilities [Member] | Asset-Specific Financings [Member]
Debt Instrument [Line Items]
Additional credit capacity						$ 500,000,000
Base Rate [Member] | GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member] | Primary [Member]
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent					1.75%
Base Rate [Member] | GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member] | Primary [Member] | Year Four [Member]
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent					1.80%
Base Rate [Member] | GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member] | Primary [Member] | Year Five [Member]
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent					1.85%
LIBOR [Member] | GE Portfolio Acquisition Facility [Member] | Weighted-Average All-in Cost of Credit [Member] | Asset Specific Borrowings [Member]
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent						1.75%	1.75%	1.75%		1.83%
LIBOR [Member] | Credit Facilities [Member] | Weighted-Average Cash Coupon [Member]
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent						1.88%	1.88%	1.88%		1.82%
LIBOR [Member] | Credit Facilities [Member] | Weighted-Average All-in Cost of Credit [Member]
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent						2.09%	2.09%	2.09%		2.02%

Secured Debt Agreements, Net 55

Secured Debt Agreements, Net - Credit Facilities (Detail)	Sep. 30, 2017USD ($)	Sep. 30, 2017GBP (£)	Sep. 30, 2017EUR (€)	Dec. 31, 2016USD ($)	Dec. 31, 2016GBP (£)	Dec. 31, 2016EUR (€)
Line of Credit Facility [Line Items]
Potential	$ 4,989,350,000
Repurchase Borrowings Outstanding	4,386,645,000
Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	7,137,810,000			$ 5,479,180,000
Collateral Assets	6,424,646,000			5,297,728,000
Potential	4,989,350,000			4,114,580,000
Repurchase Borrowings Outstanding	4,386,645,000			3,572,837,000
Available	602,705,000			541,743,000
Wells Fargo [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	2,000,000,000			2,000,000,000
Collateral Assets	2,232,117,000			1,718,874,000
Potential	1,724,227,000			1,339,942,000
Repurchase Borrowings Outstanding	1,398,224,000			1,107,733,000
Available	326,003,000			232,209,000
MetLife [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	1,000,000,000			1,000,000,000
Collateral Assets	1,030,148,000			1,106,017,000
Potential	807,164,000			862,454,000
Repurchase Borrowings Outstanding	807,164,000			862,454,000
Bank of America [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	750,000,000			750,000,000
Collateral Assets	818,359,000			794,881,000
Potential	641,066,000			617,694,000
Repurchase Borrowings Outstanding	641,066,000			617,694,000
Societe Generale [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	472,560,000		€ 400,000,000	420,680,000		€ 400,000,000
Collateral Assets	332,761,000			274,351,000
Potential	266,000,000			207,178,000
Repurchase Borrowings Outstanding	266,000,000			207,178,000
Deutsche Bank [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000
Collateral Assets	393,564,000
Potential	295,743,000
Repurchase Borrowings Outstanding	295,743,000
Citibank [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	795,350,000			500,000,000
Collateral Assets	596,119,000			508,989,000
Potential	464,849,000			394,677,000
Repurchase Borrowings Outstanding	356,751,000			229,629,000
Available	108,098,000			165,048,000
Morgan Stanley [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	669,900,000	£ 500,000,000		308,500,000	£ 250,000,000
Collateral Assets	422,332,000			344,056,000
Potential	331,037,000			272,221,000
Repurchase Borrowings Outstanding	211,105,000			231,930,000
Available	119,932,000			40,291,000
JP Morgan [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000			500,000,000
Collateral Assets	453,121,000			550,560,000
Potential	344,656,000			420,414,000
Repurchase Borrowings Outstanding	295,984,000			316,219,000
Available	48,672,000			$ 104,195,000
Bank of America - Multi. JV [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	200,000,000
Collateral Assets	87,000,000
Potential	69,600,000
Repurchase Borrowings Outstanding	69,600,000
Goldman Sachs - Multi. JV [Member] | Credit Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	250,000,000
Collateral Assets	59,125,000
Potential	45,008,000
Repurchase Borrowings Outstanding	$ 45,008,000

Secured Debt Agreements, Net 56

Secured Debt Agreements, Net - Credit Facilities (Parenthetical) (Detail) - Credit Facilities [Member]	Sep. 30, 2017USD ($)	Sep. 30, 2017GBP (£)	Sep. 30, 2017EUR (€)	Dec. 31, 2016USD ($)	Dec. 31, 2016GBP (£)	Dec. 31, 2016EUR (€)
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 7,137,810,000			$ 5,479,180,000
Maximum Facility Size	7,137,810,000			5,479,180,000
Maximum Facility Size	7,137,810,000			5,479,180,000
Maximum Facility Size	7,137,810,000			5,479,180,000
Societe Generale [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	472,560,000		€ 400,000,000	420,680,000		€ 400,000,000
Maximum Facility Size	472,560,000		400,000,000	420,680,000		400,000,000
Maximum Facility Size	472,560,000		400,000,000	420,680,000		400,000,000
Maximum Facility Size	472,560,000		400,000,000	420,680,000		€ 400,000,000
Citibank [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	795,350,000			500,000,000
Maximum Facility Size	795,350,000			500,000,000
Maximum Facility Size	795,350,000			500,000,000
Maximum Facility Size	795,350,000			500,000,000
Citibank [Member] | $250.0 Million Facility [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000
Maximum Facility Size	500,000,000
Maximum Facility Size	500,000,000
Maximum Facility Size	500,000,000
Citibank [Member] | $500.0 Million Facility [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	295,400,000		250,000,000
Maximum Facility Size	295,400,000		250,000,000
Maximum Facility Size	295,400,000		250,000,000
Maximum Facility Size	295,400,000		€ 250,000,000
Citibank [Member] | UK Pound Sterling 153.0 Million ($226.7 Million) Facility [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size				500,000,000
Maximum Facility Size				500,000,000
Maximum Facility Size				500,000,000
Maximum Facility Size				500,000,000
Morgan Stanley [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	669,900,000	£ 500,000,000		308,500,000	£ 250,000,000
Maximum Facility Size	669,900,000	500,000,000		308,500,000	250,000,000
Maximum Facility Size	669,900,000	500,000,000		308,500,000	250,000,000
Maximum Facility Size	669,900,000	£ 500,000,000		308,500,000	£ 250,000,000
JP Morgan [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000			500,000,000
Maximum Facility Size	500,000,000			500,000,000
Maximum Facility Size	500,000,000			500,000,000
Maximum Facility Size	500,000,000			500,000,000
JP Morgan [Member] | $250.0 Million Facility [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000			500,000,000
Maximum Facility Size	500,000,000			500,000,000
Maximum Facility Size	500,000,000			500,000,000
Maximum Facility Size	$ 500,000,000			$ 500,000,000

Secured Debt Agreements, Net 57

Secured Debt Agreements, Net - Summary of Key Terms of Credit Facilities (Detail) € in Thousands, £ in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2017GBP (£)	Sep. 30, 2017EUR (€)
Line of Credit Facility [Line Items]
Outstanding Borrowings	$ 4,386,645
Potential Borrowings	$ 4,989,350
Rate	1.88%
Advance Rate	78.80%
Credit Facilities [Member]
Line of Credit Facility [Line Items]
Outstanding Borrowings	$ 4,386,645	$ 3,572,837
Potential Borrowings	$ 4,989,350	$ 4,114,580
Advance Rate	78.80%	79.10%
Credit Facilities [Member] | 1-Month USD LIBOR [Member]
Line of Credit Facility [Line Items]
Outstanding Borrowings	$ 4,123,064
Potential Borrowings	$ 4,610,777
Rate	1.86%
Advance Rate	78.80%
Credit Facilities [Member] | 3-Month EURIBOR [Member]
Line of Credit Facility [Line Items]
Outstanding Borrowings | €				€ 66,186
Potential Borrowings | €				€ 87,786
Rate	2.24%
Advance Rate	80.00%
Credit Facilities [Member] | 3-Month GBP LIBOR [Member]
Line of Credit Facility [Line Items]
Outstanding Borrowings | £			£ 138,371
Potential Borrowings | £			£ 205,152
Rate	2.24%
Advance Rate	78.60%
Credit Facilities [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Guarantee	25.00%
Margin Call	Collateral marks only
Term/Maturity	Term matched
Outstanding Borrowings	$ 1,398,224	$ 1,107,733
Potential Borrowings	$ 1,724,227	1,339,942
Credit Facilities [Member] | MetLife [Member]
Line of Credit Facility [Line Items]
Guarantee	50.00%
Margin Call	Collateral marks only
Term/Maturity	Apr. 21, 2023
Outstanding Borrowings	$ 807,164	862,454
Potential Borrowings	$ 807,164	862,454
Credit Facilities [Member] | Bank of America [Member]
Line of Credit Facility [Line Items]
Guarantee	50.00%
Margin Call	Collateral marks only
Term/Maturity	May 21, 2021
Outstanding Borrowings	$ 641,066	617,694
Potential Borrowings	$ 641,066	617,694
Credit Facilities [Member] | Societe Generale [Member]
Line of Credit Facility [Line Items]
Guarantee	25.00%
Margin Call	Collateral marks only
Term/Maturity	Term matched
Outstanding Borrowings	$ 266,000	207,178
Potential Borrowings	$ 266,000	207,178
Credit Facilities [Member] | Deutsche Bank [Member]
Line of Credit Facility [Line Items]
Guarantee	35.00%
Margin Call	Collateral marks only
Term/Maturity	Term matched
Outstanding Borrowings	$ 295,743
Potential Borrowings	$ 295,743
Credit Facilities [Member] | Citibank [Member]
Line of Credit Facility [Line Items]
Guarantee	25.00%
Margin Call	Collateral marks only
Term/Maturity	Term matched
Outstanding Borrowings	$ 356,751	229,629
Potential Borrowings	$ 464,849	394,677
Credit Facilities [Member] | Morgan Stanley [Member]
Line of Credit Facility [Line Items]
Guarantee	25.00%
Margin Call	Collateral marks only
Term/Maturity	Mar. 3, 2020
Outstanding Borrowings	$ 211,105	231,930
Potential Borrowings	$ 331,037	272,221
Credit Facilities [Member] | JP Morgan [Member]
Line of Credit Facility [Line Items]
Guarantee	50.00%
Margin Call	Collateral marks only
Term/Maturity	Jan. 7, 2020
Outstanding Borrowings	$ 295,984	316,219
Potential Borrowings	$ 344,656	$ 420,414
Credit Facilities [Member] | Bank of America - Multi. JV [Member]
Line of Credit Facility [Line Items]
Guarantee	43.00%
Margin Call	Collateral marks only
Term/Maturity	Jul. 19, 2021
Outstanding Borrowings	$ 69,600
Potential Borrowings	$ 69,600
Credit Facilities [Member] | Goldman Sachs - Multi. JV [Member]
Line of Credit Facility [Line Items]
Guarantee	25.00%
Margin Call	Collateral marks only
Term/Maturity	Jul. 12, 2020
Outstanding Borrowings	$ 45,008
Potential Borrowings	$ 45,008

Secured Debt Agreements, Net 58

Secured Debt Agreements, Net - Summary of Key Terms of Credit Facilities (Parenthetical) (Detail) - Credit Facilities [Member]	9 Months Ended
	Sep. 30, 2017ExtensionOptions
MetLife [Member]
Line of Credit Facility [Line Items]
Maturity period	Includes five one-year extension options which may be exercised at our sole discretion.
Number of extension options	5
Term of maturity date	1 year
Bank of America [Member]
Line of Credit Facility [Line Items]
Maturity period	Includes two one-year extension options which may be exercised at our sole discretion.
Number of extension options	2
Term of maturity date	1 year

Secured Debt Agreements, Net 59

Secured Debt Agreements, Net - Summary of Asset-Specific Financings (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Participating Mortgage Loans [Line Items]
Collateral assets, Book Value	$ 659,152	$ 869,417
Financing provided, Book Value	516,537	676,333
Collateral assets, Principal Balance	662,223	876,083
Financing provided, Principal Balance	$ 517,256	$ 679,207
Collateral Assets [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Term	2020-12	2020-08
Count | SecurityLoan	5	7
LIBOR [Member] | Collateral Assets [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost Rate	4.70%	4.84%
Asset-Specific Financings [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Term	2020-12	2020-08
Guarantee	$ 162,517	$ 231,585
Financing provided, Principal Balance	$ 517,256	$ 679,207
Count | SecurityLoan	5	7
Asset-Specific Financings [Member] | LIBOR [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost Rate	2.48%	2.60%

Secured Debt Agreements, Net 60

Secured Debt Agreements, Net - Summary of Asset-Specific Financings (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Participating Mortgage Loans [Line Items]
Borrowings	$ 517,256	$ 679,207
Asset-Specific Financings [Member]
Participating Mortgage Loans [Line Items]
Borrowings	517,256	679,207
Cross Collateral Assets [Member] | Asset-Specific Financings [Member]
Participating Mortgage Loans [Line Items]
Borrowings	$ 394,800	$ 392,300

Loan Participations Sold, Net -

Loan Participations Sold, Net - Summary of Statistics for Loan Participations Sold (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)Loans	Dec. 31, 2016USD ($)Loans
Participating Mortgage Loans [Line Items]
Count | Loans	1	1
Principal Balance	$ 93,710	$ 419,560
Book Value, Total Loan	$ 9,637,152	$ 8,692,978
Weighted Average Term	2022-02	2019-12
Book Value	$ 33,193	$ 348,077
Senior Participation [Member]
Participating Mortgage Loans [Line Items]
Count | Loans	1	1
Principal Balance	$ 33,193	$ 349,633
Guarantee		$ 29,616
Weighted Average Term	2022-02	2019-12
Book Value	$ 33,193	$ 348,077
Loan Participations Sold [Member]
Participating Mortgage Loans [Line Items]
Book Value, Total Loan	$ 91,498	$ 416,233
LIBOR [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost	5.96%	4.48%
LIBOR [Member] | Senior Participation [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost	4.00%	2.72%

Loan Participations Sold, Net62

Loan Participations Sold, Net - Summary of Statistics for Loan Participations Sold (Parenthetical) (Detail) $ in Thousands, £ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017GBP (£)	Dec. 31, 2016USD ($)
Participating Mortgage Loans [Line Items]
Guarantor obligations					£ 24	$ 29,600
Interest paid			$ 141,124	$ 123,564
Deferred financing costs	$ 17,462		17,462			15,272
Loan Participations Sold [Member]
Participating Mortgage Loans [Line Items]
Interest expense	4,000	$ 3,400	9,300	10,700
Interest paid	$ 2,600	$ 3,200	$ 7,700	$ 10,300
Deferred financing costs						$ 1,600

Securitized Debt Obligations,63

Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)Loans
Debt Instrument [Line Items]
Count | Loans	1
Principal Balance	$ 474,620
Book Value	$ 474,298
Term	2033-06
Loans [Member]
Debt Instrument [Line Items]
Count | Loans	1
Principal Balance	$ 644,788
Book Value	$ 641,262
Term	2023-06
LIBOR [Member]
Debt Instrument [Line Items]
Yield/Cost	1.94%
LIBOR [Member] | Loans [Member]
Debt Instrument [Line Items]
Yield/Cost	3.60%

Securitized Debt Obligations,64

Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Loans Managed, Securitized or Asset-backed Financing Arrangement [Abstract]
Interest expense on securitized debt obligations	$ 3.8	$ 3.8

Securitized Debt Obligations,65

Securitized Debt Obligations, Net - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans Managed, Securitized or Asset-backed Financing Arrangement [Abstract]
Securitized debt obligations	$ 474,298	$ 0

Convertible Notes, Net - Summar

Convertible Notes, Net - Summary of Outstanding Convertible Senior Notes (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
5.25% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Note Issuance	2013-11
Face Value	$ 172,500
Coupon Rate	5.25%
All-in Cost	5.87%
Conversion Rate	36.1380
Maturity	2018-12
4.38% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Note Issuance	2017-05
Face Value	$ 402,500
Coupon Rate	4.38%
All-in Cost	4.85%
Conversion Rate	28.0324
Maturity	2022-05

Convertible Notes, Net - Summ67

Convertible Notes, Net - Summary of Outstanding Convertible Senior Notes (Parenthetical) (Detail)	Jun. 28, 2017USD ($)$ / shares	May 31, 2017USD ($)$ / shares	Nov. 30, 2013USD ($)$ / shares	Sep. 30, 2017
4.38% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, common stock issued, in percent				28.0324
4.38% Convertible Senior Notes [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount | $		$ 1,000
Debt instrument, conversion price | $ / shares		$ 35.67
Convertible Notes, debt conversion, common stock issued, in percent		27.6700
Convertible Senior Notes [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount | $	$ 1,000		$ 1,000
Debt instrument, conversion price | $ / shares	$ 27.99		$ 35.67
Convertible Notes, debt conversion, common stock issued, in percent	35.7236		27.6700

Convertible Notes, Net - Additi

Convertible Notes, Net - Additional Information (Detail) - USD ($)	1 Months Ended		9 Months Ended
	May 31, 2017	Nov. 30, 2013	Sep. 30, 2017	Sep. 29, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Convertible notes, net			$ 562,741,000		$ 166,762,000
Accrued interest payable			19,922,000		9,049,000
5.25% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Senior Notes, Principal amount			$ 172,500,000
Description of Convertible Notes conversion			The Convertible Notes are convertible at the holders' option into shares of our class A common stock, only under specific circumstances, prior to the close of business on August 31, 2018 and January 31, 2022, for the November 2013 and May 2017 convertible notes, respectively, at the applicable conversion rate in effect on the conversion date.
Debt instrument, conversion price				$ 31.02
Discount upon issuance of Convertible Notes		$ 9,100,000
Debt issuance costs		$ 4,100,000
Convertible Notes, assumed effective interest rate		6.50%
Convertible Senior Notes, Interest rate including amortization of discount upon issuance		7.16%
Accrued interest payable			$ 9,000,000		$ 755,000
4.38% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Senior Notes, Principal amount			402,500,000
Discount upon issuance of Convertible Notes	$ 979,000
Debt issuance costs	$ 8,400,000
Convertible Notes, assumed effective interest rate	4.57%
Convertible Senior Notes, Interest rate including amortization of discount upon issuance	4.91%
May 2017 Convertible Notes [Member]
Debt Instrument [Line Items]
Convertible Senior Notes, Principal amount	$ 287,500,000		115,000,000
Convertible notes, net			$ 402,500,000

Convertible Notes, Net - Summ69

Convertible Notes, Net - Summary of Details about Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Discount and issuance cost amortization			$ 16,356	$ 15,129
Convertible Senior Note [Member]
Debt Instrument [Line Items]
Cash coupon	$ 6,247	$ 2,264	12,732	6,792
Discount and issuance cost amortization	1,202	691	2,869	2,038
Total interest expense	$ 7,449	$ 2,955	$ 15,601	$ 8,830

Convertible Notes, Net - Summ70

Convertible Notes, Net - Summary of Details of Net Book Value of Convertible Note (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Deferred financing costs	$ (17,462)	$ (15,272)
Net book value	562,741	166,762
Convertible Senior Note [Member]
Debt Instrument [Line Items]
Face Value	575,000	172,500
Unamortized discount	(11,386)	(5,532)
Deferred financing costs	(873)	(206)
Net book value	$ 562,741	$ 166,762

Derivative Financial Instrume71

Derivative Financial Instruments - Summary of Outstanding Foreign Exchange Derivatives Designated as Net Investment Hedges of Foreign Currency Risk (Detail) - Sell [Member] - Designated as Hedging Instrument [Member] - Foreign Exchange Forward [Member] - Net Investment Hedges [Member] € in Thousands, £ in Thousands, CAD in Thousands	Sep. 30, 2017GBP (£)DerivativeInstrument	Sep. 30, 2017CADDerivativeInstrument	Dec. 31, 2016GBP (£)DerivativeInstrument	Dec. 31, 2016EUR (€)DerivativeInstrument	Dec. 31, 2016CADDerivativeInstrument
EUR [Member]
Derivative [Line Items]
Number of Instruments			1	1	1
Notional Amount | €				€ 44,900
GBP [Member]
Derivative [Line Items]
Number of Instruments	1	1	2	2	2
Notional Amount | £	£ 112,700		£ 141,900
CAD [Member]
Derivative [Line Items]
Number of Instruments	1	1	2	2	2
Notional Amount | CAD		CAD 102,000			CAD 122,900

Derivative Financial Instrume72

Derivative Financial Instruments - Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk (Detail) - Cash Flow Hedges [Member] - Designated as Hedging Instrument [Member] £ in Thousands, CAD in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)DerivativeInstrument	Dec. 31, 2016USD ($)DerivativeInstrument	Sep. 30, 2017CADDerivativeInstrument	Dec. 31, 2016GBP (£)DerivativeInstrument	Dec. 31, 2016CADDerivativeInstrument
Interest Rate Caps [Member] | GBP [Member] | GBP LIBOR [Member]
Derivative [Line Items]
Number of Instrument		1		1	1
Notional Amount | £				£ 15,142
Strike		2.00%		2.00%	2.00%
Wtd. Avg. Maturity (Years)		3 months 19 days
Interest Rate Caps [Member] | USD [Member] | USD LIBOR [Member]
Derivative [Line Items]
Number of Instrument	9	21	9	21	21
Notional Amount | $	$ 204,248	$ 802,256
Strike	2.40%	2.00%	2.40%	2.00%	2.00%
Wtd. Avg. Maturity (Years)	1 year 8 months 12 days	4 months 24 days
Interest Rate Caps [Member] | CAD [Member] | CDOR [Member]
Derivative [Line Items]
Number of Instrument	3	5	3	5	5
Notional Amount | CAD			CAD 23,370		CAD 400,035
Strike	2.00%	2.00%	2.00%	2.00%	2.00%
Wtd. Avg. Maturity (Years)	7 months 6 days	4 months 24 days
Interest Rate Swaps [Member] | CAD [Member] | CDOR [Member]
Derivative [Line Items]
Number of Instrument	4	4	4	4	4
Notional Amount | CAD			CAD 108,183		CAD 108,271
Strike	1.00%	1.00%	1.00%	1.00%	1.00%
Wtd. Avg. Maturity (Years)	1 year 8 months 12 days	2 years 4 months 24 days

Derivative Financial Instrume73

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of collateral posted for the net assets/liability positions	$ 7,750,000		$ 7,750,000		$ 79,000
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives recorded gains (losses) during the period	$ 42,000	$ 528,000	355,000	$ 2,200,000
Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification from accumulated other comprehensive income (loss) as increase to interest income			$ 561,000
Reclassification from accumulated other comprehensive income, time period			12 months

Derivative Financial Instrume74

Derivative Financial Instruments - Summary of Non-designated Hedges (Detail) - Not Designated as Hedging Instrument [Member] € in Thousands, £ in Thousands, CAD in Thousands, $ in Thousands	Sep. 30, 2017GBP (£)DerivativeInstrument	Sep. 30, 2017EUR (€)DerivativeInstrument	Sep. 30, 2017CADDerivativeInstrument	Dec. 31, 2016USD ($)DerivativeInstrument	Dec. 31, 2016EUR (€)DerivativeInstrument	Dec. 31, 2016CADDerivativeInstrument
CAD [Member] | Buy USD / Sell CAD Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument	1	1	1
Notional Amount | CAD			CAD 15,000
CAD [Member] | Buy CAD / Sell USD [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument	1	1	1
Notional Amount | CAD			CAD 15,000
CAD [Member] | Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument				2	2	2
Notional Amount | CAD						CAD 37,221
GBP [Member] | Buy GBP / Sell USD Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument	1	1	1
Notional Amount | £	£ 35,000
GBP [Member] | Buy USD / Sell GBP Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument	1	1	1
Notional Amount | £	£ 35,000
EUR [Member] | Buy GBP / Sell EUR Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument	1	1	1	1	1	1
Notional Amount | €		€ 12,857			€ 12,857
USD [Member] | Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instrument				3	3	3
Notional Amount | $				$ 256,875

Derivative Financial Instrume75

Derivative Financial Instruments - Summary of Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	$ 1,628	$ 1,628	$ 4,086
Fair Value of Derivatives in a Liability Position	$ 7,167	7,167	210
Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position		1,238	3,599
Fair Value of Derivatives in a Liability Position		5,617	210
Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position			3,268
Fair Value of Derivatives in a Liability Position		5,617	210
Designated as Hedging Instrument [Member] | Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position		1,238	331
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position		390	487
Fair Value of Derivatives in a Liability Position		1,550
Not Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position		390	$ 487
Fair Value of Derivatives in a Liability Position		$ 1,550

Derivative Financial Instrume76

Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	$ (7,988)	$ (21,050)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	41	(900)
Net Investment [Member] | Foreign Currency Contracts [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	(8,524)	(21,757)
Cash Flow Hedges [Member] | Interest Rate Swaps/Derivatives [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	536	707
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	$ 41	$ (900)

Derivative Financial Instrume77

Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total interest and related income	$ 146,400
Interest and related expenses	67,891	$ 45,373	$ 168,917	$ 139,819
Amount of Loss Reclassified from Accumulated OCI into Income	41		(900)
Foreign Currency Contracts [Member] | Net Investment Hedges [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net cash settlements on our foreign currency forward contracts	8,700	$ 19,200	11,800	$ 17,400
Interest Rate Swaps/Derivatives [Member] | Cash Flow Hedges [Member] | Interest Income [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss Reclassified from Accumulated OCI into Income	$ 41		$ 900

Equity - Additional Information

Equity - Additional Information (Detail) - USD ($)	Oct. 13, 2017	Sep. 15, 2017	May 09, 2014	May 31, 2013	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Mar. 25, 2014
Class of Stock [Line Items]
Total stock, shares authorized					300,000,000		300,000,000		300,000,000
Common stock, shares authorized					200,000,000		200,000,000		200,000,000		200,000,000
Preferred stock, shares authorized					100,000,000		100,000,000		100,000,000
Preferred stock issued					0		0		0
Preferred stock outstanding					0		0		0
Plan adoption date									Mar. 25, 2014
Common stock, shares issued under dividend reinvestment program					428	262			971	812
Number of shares sold during period				25,875,000					971	812
Dividends declared per share of common stock		$ 0.62			$ 0.62	$ 0.62			$ 1.86	$ 1.86
Date of dividend paid									Jul. 14, 2017
Date of dividend declared									Jun. 13, 2017
Record date of dividend paid									Jun. 30, 2017
Accumulated other comprehensive loss					$ 32,362,000		$ 32,362,000		$ 32,362,000		$ 56,202,000
Net realized and unrealized gains related to changes in fair value of derivative instruments					31,100,000		31,100,000		31,100,000		51,300,000
Cumulative unrealized currency translation adjustment on assets and liabilities denominated in foreign currencies					63,500,000		63,500,000		63,500,000		107,500,000
Multifamily [Member] | Joint Venture [Member]
Class of Stock [Line Items]
Total equity					41,200,000		41,200,000		41,200,000
Equity interests owned by Blackstone Mortgage Trust, Inc.					35,000,000		35,000,000		35,000,000
Non-controlling interests					6,200,000		$ 6,200,000		6,200,000		$ 0
Subsequent Events [Member]
Class of Stock [Line Items]
Dividends paid	$ 58,800,000
Dividends paid per common stock	$ 0.62
ATM Agreements [Member]
Class of Stock [Line Items]
Aggregate sales price			$ 200,000,000
Number of shares sold during period							0	0
Aggregate sales price remaining available					$ 188,600,000		$ 188,600,000		$ 188,600,000
Dividend Reinvestment and Direct Stock Purchase Plan [Member]
Class of Stock [Line Items]
Reserved for issuance of class A common stock					9,997,356		9,997,356		9,997,356			10,000,000

Equity - Schedule of Movement i

Equity - Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units (Detail) - shares	1 Months Ended	9 Months Ended
	May 31, 2013	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Beginning balance		94,709,290	93,843,847
Issuance of class A common stock	25,875,000	971	812
Issuance of restricted class A common stock, net		286,773	209,798
Issuance of deferred stock units		20,560	20,850
Ending balance		95,017,594	94,075,307

Equity - Schedule of Movement80

Equity - Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units (Parenthetical) (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Common stock, shares issued under dividend reinvestment program	428	262	971	812
Class A Common Stock [Member]
Class of Stock [Line Items]
Deferred stock units held by directors	189,587	162,371	189,587	162,371
Common stock, shares issued under dividend reinvestment program			971	812

Equity - Schedule of Dividend A

Equity - Schedule of Dividend Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 15, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Dividends declared per share of common stock	$ 0.62	$ 0.62	$ 0.62	$ 1.86	$ 1.86
Total dividends declared		$ 58,793	$ 58,226	$ 176,374	$ 174,678

Equity - Schedule of Basic and

Equity - Schedule of Basic and Diluted Earnings Per Share, or EPS, Based on Weighted-Average of Both Restricted and Unrestricted Class A Common Stock Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income	$ 57,722	$ 64,794	$ 159,741	$ 184,921
Weighted-average shares outstanding, basic and diluted	95,013,087	94,071,537	95,004,188	94,067,923
Per share amount, basic and diluted	$ 0.61	$ 0.69	$ 1.68	$ 1.97

Other Expenses - Additional Inf

Other Expenses - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fee - percent of outstanding equity balance			1.50%
Incentive fee computation-percent of the product per agreement			20.00%
Incentive fee computation-percent of outstanding Equity per annum			7.00%
Management fees description			Manager is entitled to an incentive fee in an amount equal to the product of (i) 20% and (ii) the excess of (a) our Core Earnings (as defined in our Management Agreement) for the previous 12 month period over (b) an amount equal to 7.00% per annum multiplied by our outstanding Equity, provided that our Core Earnings over the prior three-year period is greater than zero. Core Earnings, as defined in our Management Agreement, is generally equal to our net income (loss) prepared in accordance with GAAP, excluding (i) certain non-cash items (ii) the net income (loss) related to our legacy portfolio and (iii) incentive management fees.
Management fees	$ 13,243,000	$ 13,701,000	$ 40,557,000	$ 43,161,000
Accrued management and incentive fees payable	13,243,000		13,243,000		$ 12,798,000
CT Legacy Partners [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total incentive compensation payments		354,000		1,112,000
Manager [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fees	9,500,000	9,500,000	28,600,000	28,400,000
Total incentive compensation payments	3,700,000	4,200,000	11,900,000	14,800,000
Accrued management and incentive fees payable	$ 13,200,000		$ 13,200,000		$ 12,800,000
Incentive Awards Plan [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Percentage of the dividends paid to common equity holders created employee pool	6.75%		6.75%
Incentive Awards Plan [Member] | CT Legacy Partners [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Recognized expenses for incentive plan		$ 354,000		$ 1,100,000

Other Expenses - Schedule of Ge

Other Expenses - Schedule of General and Administrative Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Professional services	$ 933	$ 828	$ 2,811	$ 2,474
Operating and other costs	489	305	1,424	1,695
Subtotal	1,422	1,133	4,235	4,169
Non-cash and CT Legacy Portfolio compensation expenses
Restricted class A common stock earned	5,819	4,855	17,496	14,190
Subtotal	5,944	6,241	17,809	16,690
General and administrative expenses	7,419	7,414	22,219	20,990
Other expenses	53	40	175	131
General and Administrative Expense [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Director stock-based compensation	125	94	313	282
Manager [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Management incentive awards plan	3,700	4,200	11,900	14,800
General and administrative expenses	$ 7,366	7,374	$ 22,044	20,859
CT Legacy Partners [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Management incentive awards plan		354		1,112
CT Opportunity Partners I, LP [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Management incentive awards plan		$ 938		$ 1,106

Other Expenses - Schedule of 85

Other Expenses - Schedule of General and Administrative Expenses (Parenthetical) (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Multifamily [Member] | Joint Venture [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Expenses related Multifamily Joint Venture.	$ 112,000	$ 112,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2013	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Tax Credit Carryforward [Line Items]
Annual distribution of net taxable income for U.S. federal income tax not to apply to our earnings that we distribute (percent)				90.00%
Net taxable income subject to distribution (percent)				100.00%
Excise tax rate				4.00%
Income tax (benefit) provision		$ 83,000	$ 194,000	$ 265,000	$ 281,000
Deferred tax assets		0		0		$ 0
Deferred tax liabilities		$ 0		$ 0		0
Common stock, shares issued	25,875,000			971	812
Net operating losses carried forward						$ 159,000,000
NOLs expiration date				Dec. 31, 2029
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses limitations				The availability of our NOLs is generally limited to $2.0 million per annum
Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year				2,014
Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year				2,016

Stock-Based Incentive Plans - A

Stock-Based Incentive Plans - Additional Information (Detail) $ / shares in Units, $ in Millions	Sep. 30, 2017USD ($)Plansshares	Sep. 30, 2017USD ($)Plansshares	Sep. 29, 2017$ / shares	Dec. 31, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of benefit plans | Plans	7	7
Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, vesting period		3 years
Number of shares of restricted class A common stock outstanding	1,261,232	1,261,232		1,309,995
Unrecognized compensation cost relating to nonvested share-based compensation | $	$ 29.8	$ 29.8
Unrecognized compensation cost expected to be recognized over weighted average period	1 year
Nonvested share-based compensation, closing price | $ / shares			$ 31.02
Expired Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan	0	0
Vest in 2020 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	745	745
Vest in 2017 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	412,480	412,480
Vest in 2018 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	542,789	542,789
Vest in 2019 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	305,218	305,218
Class A Common Stock [Member] | Stock Incentive Current Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan	1,448,852	1,448,852
Maximum number of shares available under plan	2,400,000	2,400,000

Stock-Based Incentive Plans - M

Stock-Based Incentive Plans - Movement in Outstanding Shares of Restricted Class A Common Stock and Weighted-Average Grant Date Fair Value Per Share (Detail) - Restricted Class A Common Stock [Member]	9 Months Ended
	Sep. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Class A Common Stock, Beginning Balance | shares	1,309,995
Restricted Class A Common Stock, Granted | shares	289,896
Restricted Class A Common Stock, Vested | shares	(335,536)
Restricted Class A Common Stock, Forfeited | shares	(3,123)
Restricted Class A Common Stock, Ending Balance | shares	1,261,232
Weighted-Average Grant Date Fair Value Per Share, Beginning Balance | $ / shares	$ 28.68
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	30.55
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	27.78
Weighted-Average Grant Date Fair Value Per Share, Forfeited | $ / shares	27.37
Weighted-Average Grant Date Fair Value Per Share, Ending Balance | $ / shares	$ 29.35

Fair Values - Assets and Liabil

Fair Values - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Assets
Derivatives	$ 1,628	$ 1,628	$ 4,086
Liabilities
Derivatives	7,167	$ 7,167	210
Recurring [Member]
Assets
Derivatives	1,628		4,086
Liabilities
Derivatives	7,167		210
Level 2 [Member] | Recurring [Member]
Assets
Derivatives	1,628		4,086
Liabilities
Derivatives	$ 7,167		$ 210

Fair Values - Reconciliation of

Fair Values - Reconciliation of Beginning and Ending Balances of Assets Measured at Fair Value on Recurring Basis Using Level 3 Inputs (Detail) - Level 3 [Member] - Recurring [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning	$ 12,561
Proceeds from investment realizations	(2,406)
Transfers out of level 3	(20,745)
Adjustments to fair value included in earnings
Gain on investments at fair value	11,790
Balance, ending	$ 1,200

Fair Values - Reconciliation 91

Fair Values - Reconciliation of Beginning and Ending Balances of Assets Measured at Fair Value on Recurring Basis Using Level 3 Inputs (Parenthetical) (Detail) $ in Millions	3 Months Ended
	Sep. 30, 2016USD ($)
Level 1 [Member] | Recurring [Member] | Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfer out of level 3	$ 20.7

Fair Values - Schedule of Detai

Fair Values - Schedule of Details of Carrying Amount, Face Amount, and Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financial assets
Cash and cash equivalents, face amount	$ 61,221	$ 75,567	$ 94,061
Restricted cash	32,864
Loans receivable, net, face amount	9,681,055	8,727,218
Financial liabilities
Secured debt agreements, net, face amount	6,096,597	5,731,626
Loan participations sold, net	33,193	348,077
Loan participations sold, net, face amount	93,710	419,560
Securitized debt obligations, net	474,298	0
Securitized debt obligations, net,face amount	474,620
Carrying Amount [Member]
Financial assets
Cash and cash equivalents	61,221	75,567
Restricted cash	32,864
Loans receivable, net	9,637,152	8,692,978
Financial liabilities
Secured debt agreements, net	6,079,135	5,716,354
Loan participations sold, net	33,193	348,077
Securitized debt obligations, net	474,298
Convertible notes, net	562,741	166,762
Fair Value [Member]
Financial assets
Cash and cash equivalents	61,221	75,567
Restricted cash	32,864
Loans receivable, net	9,685,422	8,733,784
Financial liabilities
Secured debt agreements, net	6,096,597	5,731,626
Loan participations sold, net	33,193	349,633
Securitized debt obligations, net	474,655
Convertible notes, net	602,503	191,763
Convertible Senior Note [Member]
Financial liabilities
Convertible notes, net, face amount	575,000	172,500
Senior Participation [Member]
Financial liabilities
Loan participations sold, net	33,193	348,077
Loan participations sold, net, face amount	$ 33,193	$ 349,633

Variable Interest Entities - Su

Variable Interest Entities - Summary of Assets and Liabilities of Consolidated Securitization VIE (Detail) $ in Thousands	Sep. 30, 2017USD ($)
Assets:
Assets	$ 500,800
VIE [Member]
Assets:
Assets	500,763
Liabilities:
Liabilities	474,902
VIE [Member] | Loans Receivable [Member]
Assets:
Assets	500,000
VIE [Member] | Other Assets [Member]
Assets:
Assets	763
VIE [Member] | Securitized Debt Obligations, Net [Member]
Liabilities:
Liabilities	474,298
VIE [Member] | Other Liabilities [Member]
Liabilities:
Liabilities	$ 604

Transactions with Related Par94

Transactions with Related Parties - Additional Information (Detail)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017USD ($)shares	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)SecurityLoanshares	Sep. 30, 2016USD ($)SecurityLoanshares	Dec. 31, 2016USD ($)SecurityLoanshares	Jun. 30, 2017USD ($)
Related Party Transaction [Line Items]
Accrued management and incentive fees payable	$ 13,243,000		$ 13,243,000		$ 12,798,000
Common stock value	$ 948,000		948,000		$ 945,000
Non-cash expenses			$ 17,809,000	$ 16,517,000
Number of Loans | SecurityLoan			111		107
Fully subscribed offering costs						$ 474,600,000
Securitized debt obligations issued, aggregate amount						$ 72,900,000
Maximum [Member]
Related Party Transaction [Line Items]
Participation percentage in individual tranches, represented by investment vehicles			49.00%
Restricted Class A Common Stock [Member]
Related Party Transaction [Line Items]
Shares held | shares	1,261,232		1,261,232		1,309,995
Restricted shares, vesting period			3 years
Restricted Class A Common Stock [Member] | Class A Common Stock [Member]
Related Party Transaction [Line Items]
Common stock, shares issued | shares			0	0
Manager [Member]
Related Party Transaction [Line Items]
Management Agreement expiration date			Dec. 19, 2017
Management Agreement renewal term, description			The current term of which expires on December 19, 2017, and will be automatically renewed for a one-year term each anniversary thereafter unless earlier terminated.
Management Agreement renewal term, period			1 year
Accrued management and incentive fees payable	$ 13,200,000		$ 13,200,000		$ 12,800,000
Management fees paid to Manager	14,400,000	$ 15,800,000	40,100,000	$ 43,800,000
Expenses reimbursed to Manager	$ 59,000	82,000	$ 325,000	$ 462,000
Number of Loans | SecurityLoan			5	1
Expenses incurred on insurance agency transaction of affiliate with loan borrower			$ 0	$ 0
Income received on insurance agency transaction of affiliate with loan borrower			$ 0	0
Manager [Member] | Class A Common Stock [Member] | Restricted Class A Common Stock [Member]
Related Party Transaction [Line Items]
Shares held | shares	607,789		607,789
Common stock value	$ 17,800,000		$ 17,800,000
Non-cash expenses	2,900,000	2,500,000	$ 8,700,000	7,100,000
Manager [Member] | Class A Common Stock [Member] | Restricted Class A Common Stock [Member] | Stock Incentive Current Plan [Member]
Related Party Transaction [Line Items]
Restricted shares, vesting period			3 years
BXMT Advisors Limited Liability Company and Affiliates [Member]
Related Party Transaction [Line Items]
Payments of preferred distributions to affiliate of our Manager		146,000		491,000
Affiliates of Manager [Member] | Third-Party Service Provider [Member]
Related Party Transaction [Line Items]
Administrative services expenses incurred	$ 87,000	$ 112,000	$ 254,000	$ 282,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)Loans	Dec. 31, 2017USD ($)Directors	Dec. 31, 2016USD ($)
Commitments And Contingencies [Line Items]
Commitments expiration period	4 years
Number of loans receivable | Loans	67
Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Number of independent directors entitled to annual compensation | Directors		5
Loans Receivable [Member]
Commitments And Contingencies [Line Items]
Unfunded loan commitments	$ 1,622,216,000		$ 882,472,000
Five Independent Board of Directors [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation		$ 175,000
Annual cash compensation paid in cash		75,000
Annual cash compensation paid in the form of deferred stock units		100,000
Chairperson of Audit Committee [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation		20,000
Audit Committee Members [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation		10,000
Compensation and Corporate Governance Committees [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation		$ 10,000