Blackstone Mortgage Trust (BXMT) 10-K 16 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 09, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
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 Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		93,929,108
Entity Public Float			$ 2,455,036,715

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 96,450	$ 51,810
Restricted cash	9,556	11,591
Loans receivable, net	9,077,007	4,428,500
Equity investments in unconsolidated subsidiaries	9,441	10,604
Other assets	184,119	70,208
Total Assets	9,376,573	4,572,713
Liabilities and Equity
Accounts payable, accrued expenses, and other liabilities	93,679	61,013
Secured debt agreements	6,116,105	2,353,279
Loan participations sold	497,032	496,080
Convertible notes, net	164,026	161,455
Total Liabilities	$ 6,870,842	$ 3,071,827
Commitments and contingencies
Equity
Additional paid-in capital	$ 3,070,200	$ 2,027,404
Accumulated other comprehensive loss	(32,758)	(15,024)
Accumulated deficit	(545,791)	(547,592)
Total Blackstone Mortgage Trust, Inc. stockholders' equity	2,492,588	1,465,371
Non-controlling interests	13,143	35,515
Total Equity	2,505,731	1,500,886
Total Liabilities and Equity	9,376,573	4,572,713
Class A Common Stock [Member]
Equity
Class A common stock, $0.01 par value, 200,000,000 shares authorized, 93,702,326 and 58,269,889 shares issued and outstanding as of December 31, 2015 and 2014, respectively	$ 937	$ 583

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - Class A Common Stock [Member] - $ / shares	Dec. 31, 2015	Dec. 31, 2014
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	93,702,326	58,269,889
Common stock, shares outstanding	93,702,326	58,269,889

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income from loans and other investments
Interest and related income	$ 410,635	$ 184,766	$ 53,164
Less: Interest and related expenses	152,416	69,143	18,017
Income from loans and other investments, net	258,219	115,623	35,147
Other expenses
Management and incentive fees	42,886	19,491	5,937
General and administrative expenses	36,709	27,799	11,505
Total other expenses	79,595	47,290	17,442
Gain on investments at fair value	21,967	13,258	7,417
Income from equity investments in unconsolidated subsidiaries	11,798	28,036
Loss on deconsolidation of subsidiary		(8,615)
Valuation allowance on loans held-for-sale			1,259
Other income			38
Income before income taxes	212,389	101,012	26,419
Income tax provision	504	518	995
Net income	211,885	100,494	25,424
Net income attributable to non-controlling interests	(15,056)	(10,449)	(10,392)
Net income attributable to Blackstone Mortgage Trust, Inc.	$ 196,829	$ 90,045	$ 15,032
Net income per share of common stock basic and diluted	$ 2.41	$ 1.86	$ 0.81
Weighted-average shares of common stock outstanding, basic and diluted	81,740,227	48,394,478	18,520,052

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net income	$ 211,885	$ 100,494	$ 25,424
Other comprehensive income
Unrealized (loss) gain on foreign currency remeasurement	(41,616)	(15,822)	798
Unrealized gain on derivative financial instruments	23,882
Other comprehensive (loss) income	(17,734)	(15,822)	798
Comprehensive income	194,151	84,672	26,222
Comprehensive income attributable to non-controlling interests	(15,056)	(10,449)	(10,392)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 179,095	$ 74,223	$ 15,830

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (loss) [Member]	Accumulated Deficit [Member]	Stockholders' Equity [Member]	Non-Controlling Interests [Member]	Class A Common Stock [Member]Common Stock [Member]
Balance at Dec. 31, 2012	$ 153,453	$ 609,002		$ (535,851)	$ 73,444	$ 80,009	$ 293
Shares of class A common stock issued, net	633,814	633,549			633,814		265
Adjustment to par value for reverse stock split and charter amendment		263					(263)
Restricted class A common stock earned	1,057	1,057			1,057
Issuance of convertible notes	8,826	8,826			8,826
Deferred directors' compensation	289	289			289
Other comprehensive income	798		$ 798		798
Consolidation of subsidiaries	11,962			5,727	5,727	6,235
Net income	25,424			15,032	15,032	10,392
Dividends declared on common stock	(21,078)			(21,078)	(21,078)
Contributions from non-controlling interests	15,000					15,000
Distributions to non-controlling interests	(72,795)					(72,795)
Balance at Dec. 31, 2013	756,750	1,252,986	798	(536,170)	717,909	38,841	295
Shares of class A common stock issued, net	766,143	765,855			766,143		288
Restricted class A common stock earned	7,983	7,983			7,983
Dividends reinvested		205		(205)
Deferred directors' compensation	375	375			375
Other comprehensive income	(15,822)		(15,822)		(15,822)
Net income	100,494			90,045	90,045	10,449
Dividends declared on common stock	(101,262)			(101,262)	(101,262)
Distributions to non-controlling interests	(13,775)					(13,775)
Balance at Dec. 31, 2014	1,500,886	2,027,404	(15,024)	(547,592)	1,465,371	35,515	583
Shares of class A common stock issued, net	1,029,540	1,029,186			1,029,540		354
Restricted class A common stock earned	12,960	12,960			12,960
Dividends reinvested	16	275		(259)	16
Deferred directors' compensation	375	375			375
Other comprehensive income	(17,734)		(17,734)		(17,734)
Net income	211,885			196,829	196,829	15,056
Dividends declared on common stock	(194,769)			(194,769)	(194,769)
Distributions to non-controlling interests	(37,428)					(37,428)
Balance at Dec. 31, 2015	$ 2,505,731	$ 3,070,200	$ (32,758)	$ (545,791)	$ 2,492,588	$ 13,143	$ 937

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income	$ 211,885	$ 100,494	$ 25,424
Adjustments to reconcile net income to net cash provided by operating activities
Gain on investments at fair value	(21,967)	(13,258)	(7,417)
Income from equity investments in unconsolidated subsidiaries	(11,798)	(28,036)
Non-cash compensation expense	20,717	9,716	6,204
Distributions of income from unconsolidated subsidiaries	5,007	17,867	8,795
Amortization of deferred fees and other items on loans	(36,053)	(19,785)	(6,290)
Amortization of deferred financing costs and other items on debt obligations	20,708	9,900	4,935
Loss on deconsolidation of subsidiary		8,615
Valuation allowance on loans held-for-sale			(1,259)
Changes in assets and liabilities, net
Other assets	(22,385)	(13,166)	116
Accounts payable, accrued expenses, and other liabilities	5,280	8,290	(1,839)
Net cash provided by operating activities	171,394	80,637	28,669
Cash flows from investing activities
Origination and fundings of loans receivable	(7,204,487)	(3,067,263)	(2,327,913)
Principal collections and proceeds from the sale of loans receivable and other assets	2,347,966	620,413	508,718
Origination and exit fees received on loans receivable	33,501	35,449	25,402
Change in restricted cash	2,035	(1,495)	4,151
Distributions from equity investments			7,151
Net cash used in investing activities	(4,820,985)	(2,412,896)	(1,782,491)
Cash flows from financing activities
Borrowings under secured debt agreements	6,885,393	3,196,939	1,667,623
Repayments under secured debt agreements	(3,030,091)	(1,926,644)	(578,484)
Proceeds from sale of loan participations	256,000	494,306	90,000
Repayment of loan participations	(238,164)	(61,836)
Proceeds from issuance of convertible notes			168,415
Repayment and purchase of secured notes			(11,059)
Payment of deferred financing costs	(21,230)	(16,160)	(8,867)
Receipts (payments) under derivative financial instruments	17,076		(6,123)
Net proceeds from issuance of class A common stock	1,029,540	766,138	633,807
Dividends paid on class A common stock	(166,978)	(84,238)	(7,776)
Contributions from non-controlling interests			15,000
Distributions to non-controlling interests	(37,428)	(13,775)	(72,853)
Repayment of other liabilities		(20,794)	(98,965)
Net cash provided by financing activities	4,694,118	2,333,936	1,790,718
Net increase in cash and cash equivalents	44,527	1,677	36,896
Cash and cash equivalents at beginning of year	51,810	52,342	15,423
Effects of currency translation on cash and cash equivalents	113	(2,209)	23
Cash and cash equivalents at end of year	96,450	51,810	52,342
Supplemental disclosure of cash flows information
Payments of interest	(127,429)	(55,174)	(12,702)
(Payments) receipts of income taxes	(125)	(1,473)	8
Supplemental disclosure of non-cash investing and financing activities
Dividends declared, not paid	(58,095)	(30,357)	(13,302)
Participations sold, net	17,836	432,470	90,000
Deconsolidation (consolidation) of subsidiaries		$ 8,615	(38,913)
Loan principal payments held by servicer	$ 118,074		$ 7,798

Organization

Organization	12 Months Ended
	Dec. 31, 2015
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 our exclusion from registration under the Investment Company Act of 1940, as amended, or the Investment Company Act. 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	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, and 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. Certain of the assets and credit of our consolidated subsidiaries are not available to satisfy the debt or other obligations of us, our affiliates, or other entities. One of our subsidiaries, CT Legacy Partners, LLC, or CT Legacy Partners, accounts for its operations in accordance with industry-specific GAAP accounting guidance for investment companies, pursuant to which it reports its investments at fair value. We have retained this accounting treatment in consolidation and, accordingly, report the loans and other investments of CT Legacy Partners at fair value on our consolidated balance sheets. Certain reclassifications have been made in the presentation of the prior period consolidated financial statements to conform to the current period presentation. 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. As of both December 31, 2015 and 2014, we did not consolidate any VIEs. 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 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 and Cash Equivalents 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 We classify the cash balances held by CT Legacy Partners as restricted because, while these cash balances are available for use by CT Legacy Partners for its operations, they cannot be used by us until our allocable share is distributed from CT Legacy Partners and cannot be commingled with any of our unrestricted cash balances. 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 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 will accrete 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 Investments in Unconsolidated Subsidiaries Our carried interest in CT Opportunity Partners I, LP, or CTOPI, is accounted for using the equity method. CTOPI’s assets and liabilities are not consolidated into our financial statements due to our determination that (i) it is not a VIE and (ii) the other investors in CTOPI have sufficient rights to preclude consolidation by us. As such, we report our allocable percentage of the net assets of CTOPI on our consolidated balance sheets. The recognition of income from CTOPI is generally deferred until cash is collected or appropriate contingencies have been eliminated. 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 freestanding derivative. For all derivatives other than those designated as freestanding derivatives, we formally document our hedge relationships and designation at 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. Changes in the fair value of the effective portion of our hedges are reflected in accumulated other comprehensive income (loss) on our consolidated financial statements. Changes in the fair value of the ineffective portion of our hedges are included in net income. Amounts are reclassified out of accumulated other comprehensive income (loss) and into net income when the hedged item is either sold or substantially liquidated. To the extent a derivative does not qualify for hedge accounting and is deemed a freestanding derivative, the changes in its value are included in net income. Repurchase Agreements 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. Loan Participations Sold Loan participations sold represent senior interests in certain loans that we sold, however we present such loan participations sold as liabilities because these arrangements do not qualify as sales under GAAP. These participations are non-recourse and remain on our consolidated balance sheet until the loan is repaid. The gross presentation of loan participations sold does not impact stockholders’ equity or net income. 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 issuance date based on our nonconvertible debt borrowing rate. The equity component of the 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 the 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 the 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 14. 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 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 on deposit and in money market funds approximates fair value. • Restricted cash: The carrying amount of restricted cash approximates fair value. • Loans receivable, net: The fair values for these loans were estimated by our Manager based on discounted cash flow methodology taking into consideration 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 contracts and interest rates caps was valued using advice from a third party derivative specialist, based on contractual cash flows and observable inputs comprising foreign currency rates and credit spreads. • Repurchase obligations: The fair values for these instruments were estimated based on the rate at which a similar credit facility would have currently priced. • Convertible notes, net: The convertible notes are actively traded and their fair values were obtained using quoted market prices for these instruments. • Loan participations sold: The fair value of these instruments were estimated based on the value of the related loan receivable asset. 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 12 for additional information. Stock-Based Compensation Our stock-based compensation consists of awards issued to our Manager and certain of its employees 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 13 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 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 class A common stock, including restricted class A common stock and deferred stock units. Refer to Note 10 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. 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. Segment Reporting We previously operated our business through two segments, the Loan Origination segment and the CT Legacy Portfolio segment. In the first quarter of 2015, as a result of asset resolutions in our CT Legacy Portfolio, our Manager determined that the CT Legacy Portfolio segment was no longer a distinct and separately managed business. Accordingly, we no longer present segment reporting. Recent Accounting Pronouncements In April 2015, the FASB issued ASU 2015-03, “Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs,” or ASU 2015-03. ASU 2015-03 simplifies the presentation of debt issuance costs by amending the accounting guidance to require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability. The amendments presented in ASU 2015-03 are consistent with the accounting guidance related to debt discounts. We adopted ASU 2015-03 in the fourth quarter of 2015 and applied its provisions retrospectively. This resulted in the reclassification of unamortized deferred financing costs from other assets to reductions in secured debt agreements, loan participations sold, and convertible notes of $12.1 million, $3.4 million, and $398,000, respectively, on our consolidated balance sheet as of December 31, 2014. Other than this reclassification, the adoption of this standard did not have an impact on our consolidated financial statements. In February 2015, the FASB issued ASU 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis,” or ASU 2015-02. ASU 2015-02 amends the guidance related to accounting for the consolidation of certain legal entities. The modifications made in ASU 2015-02 impact limited partnerships and similar legal entities, the evaluation of (i) fees paid to a decision maker or a service provider as a variable interest, (ii) fee arrangements, and (iii) related parties on the primary beneficiary determination. ASU 2015-02 is effective for the first interim or annual period beginning after December 15, 2015. We adopted ASU 2015-02 in the second quarter of 2015 and the adoption of this standard did not have a material impact on our consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, “Presentation of Financial Statements – Going Concern (Subtopic 2015-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” or ASU 2014-15. ASU 2014-15 introduces an explicit requirement for management to assess and provide certain disclosures if there is substantial doubt about an entity’s ability to continue as a going concern. ASU 2014-15 is effective for the annual period ending after December 15, 2016. We do not anticipate that the adoption of ASU 2014-15 will have a material impact on our consolidated financial statements. In June 2014, the FASB issued ASU 2014-11, “Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures,” or ASU 2014-11. ASU 2014-11 amends the accounting guidance for repurchase-to-maturity transactions and repurchase agreements executed as repurchase financings, and requires additional disclosure about certain transactions by the transferor. ASU 2014-11 is effective for certain transactions that qualify for sales treatment for the first interim or annual period beginning after December 15, 2014. The new disclosure requirements for repurchase agreements, securities lending transactions, and repurchase-to-maturity transactions that qualify for secured borrowing treatment is effective for annual periods beginning after December 15, 2014, and for interim periods beginning after March 15, 2015. We have historically recorded our repurchase arrangements as secured borrowings and, accordingly, the adoption of ASU 2014-11 did not have a material impact on our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606) ,

Loans Receivable

Loans Receivable	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Loans Receivable	3. LOANS RECEIVABLE During the second quarter of 2015, we completed the acquisition of a $4.9 billion portfolio of commercial mortgage loans secured by properties located in North America and Europe from General Electric Capital Corporation, or GE, and certain of its affiliates and joint venture partnerships. During the year ended December 31, 2015, we originated and acquired $7.5 billion of loans, inclusive of the GE acquisition, and funded $221.1 million under existing loans. The following table details overall statistics for our loans receivable portfolio as of December 31, 2015 ($ in thousands): Floating Rate Fixed Rate Total Number of loans 92 33 125 Principal balance $ 7,098,180 $ 2,010,181 $ 9,108,361 Net book value $ 7,064,279 $ 2,012,728 $ 9,077,007 Unfunded loan commitments (1) $ 696,276 $ 4,382 $ 700,658 Weighted-average cash coupon (2) L+4.09 % 5.63 % 4.84 % Weighted-average all-in yield (2) L+4.49 % 5.78 % 5.18 % Weighted-average maximum maturity (years) (3) 3.3 2.6 3.1 (1) Unfunded commitments will primarily be funded to finance property improvements or lease-related expenditures by the borrowers. These future commitments will expire over the next four years. (2) As of December 31, 2015, our floating rate loans were indexed to various benchmark rates, with 84% of floating rate loans indexed to USD LIBOR. In addition, $147.9 million of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 1.80%, as of December 31, 2015. In addition to cash coupon, all-in yield includes the amortization of deferred origination fees, loan origination costs, purchase discounts, and accrual of both extension and exit fees. Cash coupon and all-in yield for the total portfolio assume applicable floating benchmark rate for weighted-average calculation. (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of December 31, 2015, 64% of our loans were subject to yield maintenance or other prepayment restrictions and 36% were open to repayment by the borrower without penalty. As of December 31, 2014, our loan portfolio was 100% comprised of floating rate loans. The following table details overall statistics for our loans receivable portfolio as of December 31, 2014 ($ in thousands): December 31, 2014 Number of loans 60 Principal balance $ 4,462,897 Net book value $ 4,428,500 Unfunded loan commitments (1) $ 513,229 Weighted-average cash coupon (2) L+4.36 % Weighted-average all-in yield (2) L+4.81 % Weighted-average maximum maturity (years) (3) 3.9 (1) Unfunded commitments will primarily be funded to finance property improvements or lease-related expenditures by the borrowers. These future commitments will expire over the next four years. (2) As of December 31, 2014, all of our loans were floating rate loans and were indexed to various benchmark rates, with 79% of floating rate loans indexed to USD LIBOR. In addition, 14% of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 0.31%, as of December 31, 2014. In addition to cash coupon, all-in yield includes the amortization of deferred origination fees, loan origination costs, and accrual of both extension and exit fees. (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of December 31, 2014, 85% of our loans were subject to yield maintenance or other prepayment restrictions and 15% were open to repayment by the borrower without penalty. Activity relating to our loans receivable portfolio was as follows ($ in thousands): Principal Balance Deferred Fees / (1) Net Book Value December 31, 2013 $ 2,077,227 $ (30,004 ) $ 2,047,223 Loan originations, acquisitions, and fundings 3,067,263 — 3,067,263 Loan repayments (591,246 ) — (591,246 ) Unrealized (loss) gain on foreign currency translation (52,801 ) 725 (52,076 ) Deferred fees and other items (1) — (35,449 ) (35,449 ) Amortization of fees and other items (1) — 19,785 19,785 Charge-offs (2) (10,546 ) 10,546 — Reclassification to other assets (27,000 ) — (27,000 ) December 31, 2014 $ 4,462,897 $ (34,397 ) $ 4,428,500 Loan originations, acquisitions, and fundings 7,203,145 — 7,203,145 Loan repayments (2,407,920 ) — (2,407,920 ) Unrealized (loss) gain on foreign currency translation (149,761 ) 492 (149,269 ) Deferred fees and other items (1) — (33,501 ) (33,501 ) Amortization of fees and other items (1) — 36,052 36,052 December 31, 2015 $ 9,108,361 $ (31,354 ) $ 9,077,007 (1) Other items primarily consist of purchase discounts or premiums, exit fees, and deferred origination expenses. (2) Represents the charge off of a loan held by CT Legacy Partners that was fully reserved in a prior year. The tables below detail the types of loans in our loan portfolio, as well as the property type and geographic distribution of the properties securing these loans ($ in thousands): December 31, 2015 December 31, 2014 Asset Type Net Book Value Percentage Net Book Value Percentage Senior loans (1) $ 8,847,044 97 % $ 4,340,586 98 % Subordinate loans (2) 229,963 3 87,914 2 $ 9,077,007 100 % $ 4,428,500 100 % Property Type Net Book Value Percentage Net Book Value Percentage Office $ 4,039,521 45 % $ 1,878,605 42 % Hotel 1,903,544 21 1,267,486 29 Manufactured housing 1,361,572 15 — — Retail 684,944 8 270,812 6 Multifamily 580,112 6 426,094 10 Condominium 127,434 1 315,686 7 Other 379,880 4 269,817 6 $ 9,077,007 100 % $ 4,428,500 100 % Geographic Location Net Book Value Percentage Net Book Value Percentage United States Northeast $ 2,260,392 25 % $ 1,383,258 31 % Southeast 1,836,766 20 657,484 15 West 1,125,238 12 628,275 14 Southwest 1,035,839 11 405,741 9 Midwest 616,964 7 335,406 8 Northwest 390,307 4 138,796 3 Subtotal 7,265,506 79 3,548,960 80 International United Kingdom 888,998 10 622,692 14 Canada 561,023 6 137,024 3 Germany 235,294 3 — — Spain 66,661 1 86,289 2 Netherlands 59,525 1 33,535 1 Subtotal 1,811,501 21 879,540 20 Total $ 9,077,007 100 % $ 4,428,500 100 % (1) Includes senior mortgages and similar credit quality loans, including related contiguous subordinate loans, and pari passu participations in senior mortgage loans. (2) Includes mezzanine loans and subordinate interests in mortgages. 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): December 31, 2015 December 31, 2014 Risk Rating Number Principal Net Book Value Number Principal Net Book Value 1 12 $ 925,443 $ 919,991 5 $ 209,961 $ 209,112 2 77 5,948,922 5,929,447 44 3,339,972 3,313,906 3 35 2,120,713 2,114,531 11 912,964 905,482 4 1 113,283 113,038 — — — 5 — — — — — — 125 $ 9,108,361 $ 9,077,007 60 $ 4,462,897 $ 4,428,500 We did not have any impaired or nonaccrual loans as of December 31, 2015 or 2014. During the third quarter of 2015, one of the loans in our portfolio with a net book value of $113.0 million experienced a maturity default as a result of not meeting certain loan covenants. During the fourth quarter of 2015, the loan was modified to include, among other changes: a redetermination of asset release pricing; an additional borrower contribution of capital; and an extension of the maturity date to February 29, 2016. We are presently negotiating a longer term modification to provide the borrower with additional time to repay our loan from the sale of the collateral assets. As of December 31, 2015, the borrower is current with all terms of the loan and we expect to collect all contractual amounts due thereunder. We did not have any loans in maturity default as of December 31, 2014.

Equity Investments in Unconsoli

Equity Investments in Unconsolidated Subsidiaries	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments in Unconsolidated Subsidiaries	4. EQUITY INVESTMENTS IN UNCONSOLIDATED SUBSIDIARIES As of December 31, 2015 and 2014, our equity investments in unconsolidated subsidiaries consisted solely of our carried interest in CTOPI, a fund sponsored and managed by an affiliate of our Manager. Activity relating to our equity investments in unconsolidated subsidiaries was ($ in thousands): CTOPI Total as of December 31, 2013 $ 22,480 Distributions (17,867 ) Deferred income allocation (1) 5,991 Total as of December 31, 2014 $ 10,604 Distributions (5,007 ) Income allocation (1) 3,844 Total as of December 31, 2015 $ 9,441 (1) In instances where we have not received cash or all appropriate contingencies have not been eliminated, we have deferred the recognition of promote revenue allocated to us from CTOPI in respect of our carried interest in CTOPI, and recorded an offsetting liability as a component of accounts payable, accrued expenses, and other liabilities on our consolidated balance sheets. Our carried interest in CTOPI entitles 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. As of December 31, 2015, we had been allocated $9.4 million of promote revenue from CTOPI based on a hypothetical liquidation of the fund at its net asset value. Accordingly, we have recognized this allocation as an equity investment in CTOPI on our consolidated balance sheets. Generally, we defer recognition of income from CTOPI until cash is received or earned, pending distribution, and appropriate contingencies have been eliminated. We recognized promote income from CTOPI in respect of our carried interest of $11.8 million and $28.0 million during the years ended December 31, 2015 and 2014, respectively. We did not recognize promote income from CTOPI in respect of our carried interest in 2013. This carried interest was either received in cash, or was earned and available in cash at CTOPI pending future distribution as of each respective balance sheet date. 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. Approximately 68% of the pool is two-thirds vested as of December 31, 2015, with the remainder contingent on continued employment with an affiliate of our Manager and upon our receipt of promote distributions from CTOPI. The remaining 32% of the pool is fully vested as a result of an acceleration event. We recognized $5.4 million and $12.9 million of expenses under the CTOPI incentive plan for the years ended December 31, 2015 and 2014, respectively. We did not incur expenses under the CTOPI incentive plan during 2013. These amounts were recognized as a component of general and administrative expenses in our consolidated statements of operations.

Other Assets

Other Assets	12 Months Ended
	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	5. OTHER ASSETS The following table details the components of our other assets ($ in thousands): December 31, December 31, Principal and interest payments held by servicer (1) $ 123,160 $ — Accrued interest receivable 37,161 17,240 Real estate debt and equity investments, at fair value (2) 14,220 49,017 Prepaid expenses 890 948 Prepaid taxes 525 534 Other 8,163 2,469 Total $ 184,119 $ 70,208 (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. (2) Real estate debt and equity investments consists of assets held by CT Legacy Partners and are measured at fair value.

Secured Debt Agreements

Secured Debt Agreements	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Secured Debt Agreements	6. SECURED DEBT AGREEMENTS Our secured financings include revolving repurchase facilities, the GE portfolio acquisition facility, and asset-specific repurchase agreements. The following table details our secured debt agreements ($ in thousands): Secured Debt Agreements Borrowings Outstanding December 31, 2015 December 31, 2014 Revolving repurchase facilities $ 2,858,714 $ 2,040,783 GE portfolio acquisition facility 3,161,291 — Asset-specific repurchase agreements 111,746 324,553 Total secured debt agreements $ 6,131,751 $ 2,365,336 Deferred financing costs (1) (15,646 ) (12,057 ) Net book value of secured debt $ 6,116,105 $ 2,353,279 (1) Costs incurred in connection with our secured debt agreements are recorded on our consolidated balance sheet when paid and recognized as a component of interest expense over the life of each related agreement. Revolving Repurchase Facilities During the year ended December 31, 2015, we entered into one new revolving repurchase facility agreement and increased the maximum facility size of five of our revolving repurchase facilities, providing an additional $1.5 billion of credit capacity. The following table details our revolving repurchase facilities ($ in thousands): December 31, 2015 Maximum Facility Size (1) Collateral Assets (2) Repurchase Borrowings Lender Potential (3) Outstanding Available (3) Wells Fargo (4) $ 1,172,000 $ 1,044,860 $ 817,562 $ 685,485 $ 132,077 Bank of America 750,000 840,884 665,861 618,944 46,917 JP Morgan (5) 787,047 864,630 689,705 596,533 93,172 Citibank (6) 537,500 604,781 461,532 370,194 91,338 MetLife 750,000 593,273 462,849 324,587 138,262 Morgan Stanley (7) 370,400 273,280 212,050 209,038 3,012 Société Générale (8) 437,320 67,416 53,933 53,933 — $ 4,804,267 $ 4,289,124 $ 3,363,492 $ 2,858,714 $ 504,778 December 31, 2014 Maximum Facility Size (1) Collateral Assets (2) Repurchase Borrowings Lender Potential (3) Outstanding Available (3) Wells Fargo (4) $ 1,000,000 $ 747,256 $ 585,737 $ 484,365 $ 101,372 Citibank (6) 500,000 621,025 472,080 392,455 79,625 Bank of America 500,000 557,810 441,201 389,347 51,854 JP Morgan (5) 488,155 544,654 422,249 341,487 80,762 MetLife 500,000 476,499 366,902 305,889 61,013 Morgan Stanley (7) 389,050 174,297 137,181 127,240 9,941 $ 3,377,205 $ 3,121,541 $ 2,425,350 $ 2,040,783 $ 384,567 (1) Maximum facility size represents the total amount of borrowings in each repurchase agreement, however these borrowings are only available to us once sufficient collateral assets have been pledged under each facility at the discretion of the lender. (2) Represents the principal balance of the collateral assets. (3) Potential borrowings represent 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 revolving credit facility. (4) The Wells Fargo maximum facility size is composed of a $1.0 billion facility and $172.0 million related solely to a specific asset with a repurchase date of July 30, 2016, compared to a $1.0 billion facility as of December 31, 2014. (5) As of December 31, 2015 the JP Morgan maximum facility size was composed of a $250.0 million facility, a £153.0 million ($226.7 million) facility, $262.5 million related solely to a specific asset with a repurchase date of January 9, 2018, and additional capacity of £32.3 million ($47.8 million) on the £153.0 million facility to be depleted as pledged assets repay, compared to a $250.0 million facility and a £153.0 million ($238.2 million) facility as of December 31, 2014. (6) As of December 31, 2015, the Citibank maximum facility size was composed of a $500.0 million facility and $37.5 million related solely to a specific asset with a repurchase date of October 9, 2017, compared to a $500.0 million facility as of December 31, 2014. (7) As of December 31, 2015 the Morgan Stanley maximum facility size represents a £250.0 million ($370.4 million) facility, compared to a £250.0 million ($389.1 million) facility as of December 31, 2014. (8) The Société Générale maximum facility size represents a €400.0 million ($437.3 million) facility. The weighted-average outstanding balance of our revolving repurchase facilities was $2.5 billion for the year ended December 31, 2015. As of December 31, 2015, we had aggregate borrowings of $2.9 billion outstanding under our revolving repurchase 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 2.04% per annum, and a weighted-average advance rate of 79.14%. As of December 31, 2015, outstanding borrowings under these facilities had a weighted-average maturity, excluding extension options and term-out provisions, of 1.4 years. The weighted-average outstanding balance of our revolving repurchase facilities was $1.4 billion for the year ended December 31, 2014. As of December 31, 2014, we had aggregated borrowings of $2.0 billion outstanding under our revolving repurchase 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 2.11% per annum, and a weighted-average advance rate of 78.13%. As of December 31, 2014, outstanding borrowings under these facilities had a weighted-average maturity, excluding extension options and term-out provisions, of 1.8 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 table outlines the key terms of our revolving repurchase facilities as of December 31, 2015: Lender Rate (1)(2) Guarantee (3) Advance Rate (1) Margin Call (4) Term/Maturity Wells Fargo L+1.78 % 25 % 79.4 % Collateral marks only Term matched (5) Bank of America L+1.69 % 50 % 79.5 % Collateral marks only May 21, 2019 (6) JP Morgan L+1.82 % 25 % 80.4 % Collateral marks only Term matched (5)(7) Citibank L+1.92 % 25 % 77.7 % Collateral marks only Term matched (5) MetLife L+1.75 % 50 % 78.1 % Collateral marks only February 24, 2021 (8) Morgan Stanley L+2.35 % 25 % 78.7 % Collateral marks only March 3, 2017 Société Générale L+1.60 % 25 % 80.0 % Collateral marks only July 13, 2018 (9) (1) Represents a weighted-average based on borrowings outstanding and collateral assets pledged as of December 31, 2015. (2) Represents weighted-average cash coupon on borrowings outstanding as of December 31, 2015. As of December 31, 2015, our floating rate loans and related liabilities were indexed to the various benchmark rates relevant in each case 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. (3) Other than amounts guaranteed based on specific collateral asset types, borrowings under our revolving repurchase facilities are non-recourse to us. (4) Margin call provisions under our revolving repurchase facilities do not permit valuation adjustments based on capital markets activity, and are limited to collateral-specific credit marks. (5) These revolving repurchase 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. (6) Includes two one-year extension options which may be exercised at our sole discretion. (7) Borrowings denominated in British pound sterling under this facility mature on January 7, 2018. (8) Includes five one-year extension options which may be exercised at our sole discretion. (9) Includes a one-year extension option which, subject to certain provisions, may be exercised at our discretion. GE Portfolio Acquisition Facility During the second quarter of 2015, concurrently with our acquisition of the GE loan portfolio, we entered into an agreement with Wells Fargo to provide us with secured financing for the acquired portfolio. As of December 31, 2015, this facility provided for $3.3 billion of financing, of which $3.2 billion was outstanding and an additional $142.6 million was available to finance future loan fundings. The GE portfolio acquisition facility is non-revolving and consists of a single master repurchase agreement providing for both (i) asset-specific borrowings for each collateral asset as well as (ii) a sequential pay advance feature. Asset-Specific Borrowings 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 will be 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 December 31, 2015, those borrowings were denominated in U.S. Dollars, Canadian Dollars, British Pounds Sterling, and Euros. 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. As of December 31, 2015, we had outstanding asset-specific borrowings of $3.1 billion under the GE portfolio acquisition facility. Sequential Pay Advance The GE portfolio acquisition facility also includes a sequential pay advance feature that provided for $237.2 million of borrowings, representing an additional 5% advance against each collateral asset pledged under the facility. Borrowings under the sequential pay advance accrue interest at a rate equal to the sum of (i) 30-day LIBOR plus (ii) a margin of 3.10%. The sequential pay advance is denominated in U.S. Dollars and will be repaid from collateral loan principal repayments, after repayment of the related asset-specific borrowing. The sequential pay advances each have a maturity date that is one year from the date of funding, and we guarantee 100% of outstanding borrowings of the sequential pay advance. As of December 31, 2015, we had outstanding sequential pay advance borrowings of $40.7 million under the GE portfolio acquisition facility. Asset-Specific Repurchase Agreements During the year ended December 31, 2015, we entered into one asset-specific repurchase agreement providing an additional $103.1 million of credit capacity. The following table details statistics for our asset-specific repurchase agreements ($ in thousands): December 31, 2015 December 31, 2014 Repurchase Collateral Repurchase Collateral Number of loans 2 2 3 4 Principal balance $ 111,746 $ 154,192 $ 324,553 $ 429,197 Book value $ 111,061 $ 153,542 $ 321,347 $ 425,680 Weighted-average cash coupon (1) L+2.52 % L+5.27 % L+2.68 % L+5.07 % Weighted-average cost / all-in yield (1) L+2.88 % L+5.83 % L+3.16 % L+5.53 % (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, cost / all-in yield includes the amortization of deferred origination fees / financing costs. The weighted-average outstanding balance of our asset-specific repurchase agreements was $340.2 million and $257.9 million for the years ended December 31, 2015 and 2014, respectively. 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 1.40 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 December 31, 2015; (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 December 31, 2015 and 2014, we were in compliance with these covenants.

Loan Participations Sold

Loan Participations Sold	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Loan Participations Sold	7. LOAN PARTICIPATIONS SOLD 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 solely based on the performance of the related loan obligation, except in one instance where we entered into a related guarantee agreement for $35.6 million. The gross presentation of loan participations sold does not impact stockholders’ equity or net income. During the year ended December 31, 2015, we sold one senior loan participation, providing an additional $256.0 million of credit capacity. The following table details statistics for our loan participations sold ($ in thousands): December 31, 2015 December 31, 2014 Participations (1) Underlying Participations (1) Underlying Number of loans 3 3 4 4 Principal balance (2) $ 498,992 $ 608,554 $ 499,433 $ 635,701 Book value (2) $ 497,032 $ 604,321 $ 496,080 $ 628,745 Weighted-average cash coupon (3) L+2.38 % L+3.93 % L+2.51 % L+4.10 % Weighted-average cost / all-in yield (3) L+2.49 % L+4.15 % L+2.71 % L+4.71 % (1) During the years ended December 31, 2015 and 2014, we recorded $18.3 million and $12.4 million, respectively, of interest expense related to our loan participations sold, of which $16.9 million and $11.7 million, respectively, was paid in cash. (2) The difference between principal balance and book value of loan participations sold is due to deferred financing costs of $2.0 million and $3.4 million as of December 31, 2015 and 2014, respectively. (3) Our floating rate loans and related liabilities were 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, all-in cost / yield includes the amortization of deferred origination fees / financing costs.

Convertible Notes, Net

Convertible Notes, Net	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Convertible Notes, Net	8. CONVERTIBLE NOTES, NET In November 2013, we issued $172.5 million of 5.25% convertible senior notes due on December 1, 2018, or Convertible Notes. The Convertible Notes’ issuance costs are amortized through interest expense over the life of the Convertible Notes using the effective interest method. Including this amortization, our all-in cost of the Convertible Notes is 5.87% per annum. 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, 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. The Convertible Notes were not convertible as of December 31, 2015. The conversion rate was initially set to equal 34.8943 shares of class A common stock per $1,000 principal amount of Convertible Notes, which was equivalent to an initial conversion price of $28.66 per share of class A common stock, subject to adjustment upon the occurrence of certain events. In the fourth quarter of 2015, as a result of exceeding the cumulative dividend threshold as defined in the Convertible Notes Supplemental Indenture, the conversion rate was adjusted to 35.2653 shares of Class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to a conversion price of $28.36 per share of class A common stock. We may not redeem the Convertible Notes prior to maturity. As of December 31, 2015, the conversion option value was zero based on the price of our class A common stock of $26.76. In addition, we have the intent and ability to settle the Convertible Notes in cash. As a result, the Convertible Notes did not have any impact on our diluted earnings per share. Upon issuance of the Convertible Notes, we recorded a $9.1 million discount based on the implied value of the conversion option and an assumed 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 Convertible Notes is 7.16% per annum. During the year ended December 31, 2015, we incurred total interest on our convertible notes of $11.6 million, of which $9.1 million related to cash coupon and $2.5 million related to the amortization of discount and certain issuance costs. During the year ended December 31, 2014, we incurred total interest on our convertible notes of $11.5 million, of which $9.1 million related to cash coupon and $2.4 million related to the amortization of discount and certain issuance costs. During the year ended December 31, 2013, we incurred total interest on our convertible notes of $1.1 million, of which $874,000 related to cash coupon and $197,000 related to the amortization of discount and certain issuance costs. As of December 31, 2015, the Convertible Notes were carried on our consolidated balance sheet at $164.0 million, net of an unamortized discount of $8.2 million and deferred financing costs of $305,000. Accrued interest payable for the Convertible Notes was $755,000 as of December 31, 2015 and 2014. Refer to Note 2 for additional discussion of our accounting policies for the Convertible Notes.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	9. DERIVATIVE FINANCIAL INSTRUMENTS Risk Management Objective of Using Derivatives Certain of our foreign operations expose us to fluctuations of foreign interest rates and exchange rates. These fluctuations may impact the value of our cash receipts and payments in terms of our functional currency, the U.S. Dollar. In addition, we enter into derivative financial instruments to protect the value or fix the amount of certain obligations in terms of the U.S. Dollar. In addition, we use derivative financial instruments, which include interest rate caps and may also include interest rate swaps, options, floors and other interest rate derivative contracts, to hedge all or a portion of the interest rate risk associated with our borrowings. The principal objective of such arrangements is to minimize the risks and/or costs associated with our operating and financing structure as well as to hedge specific transactions. We do not intend to utilize derivatives for speculative or other purposes. The use of derivative financial instruments carries certain risks, including the risk that the counterparties to these contractual arrangements are not able to perform under the agreements. To mitigate this risk, we only enter into derivative financial instruments with counterparties with high credit ratings and with 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 We have made investments in foreign entities that expose us to fluctuations between the U.S. Dollar and the foreign currency of each such investment. Currently, we use derivative financial instruments to manage, or hedge, the variability in the carrying value of certain of our net investments in consolidated, foreign currency-denominated subsidiaries caused by the fluctuations in foreign currency exchange rates. For derivatives that are designated and qualify as a hedge of our net investment in a foreign currency, the gain or loss on such derivatives is reported in other comprehensive income as part of the cumulative translation adjustment to the extent it is effective. Any ineffective portion of a net investment hedge is recognized in our consolidated statements of operations. For derivatives that are not designated as hedging instruments, gains or losses are recognized in our consolidated statements of operations as incurred. The following table details our outstanding foreign exchange derivatives that were designated as net investment hedges of foreign currency risk (notional amount in thousands): December 31, 2015 December 31, 2014 Foreign Currency Number of Notional Amount Foreign Currency Number of Notional Amount Sell CAD Forward 2 C$ 154,900 Sell CAD Forward 1 C$ 42,525 Sell GBP Forward 2 £ 90,400 Sell EUR Forward 1 € 49,000 Cash Flow Hedges of Interest Rate Risk Our objective in using interest rate derivatives is to add stability to interest expense and to manage our exposure to interest rate movements. In addition, we may be required by our lenders to enter into certain derivative contracts related to our credit facilities. To accomplish this objective, we primarily use interest rate caps. Interest rate caps designated as cash flow hedges involve the receipt of variable-rate amounts if interest rates rise above a certain level in exchange for an up-front premium. The effective portion of changes in the fair value of derivatives designated and qualifying as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged transaction affects net income. These derivatives were used to hedge the variable cash flows associated with floating rate debt. The ineffective portion of the change in fair value of such derivatives is recognized directly in net income. During the years ended December 31, 2015, 2014, and 2013, we recorded no hedge ineffectiveness in our consolidated statements of operations. Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on our floating rate debt. During the twelve months following December 31, 2015, we estimate that an additional $780,000 will be reclassified from other accumulated comprehensive income as an increase to interest expense. As of December 31, 2015, we had the following outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk (notional amount in thousands): Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Caps 26 $ 1,097,632 2 % USD LIBOR 1.3 Interest Rate Caps 7 C 483,286 2 % CDOR 1.2 Interest Rate Caps 1 € 152,710 2 % EURIBOR 1.0 Interest Rate Caps 1 £ 15,142 2 % GBP LIBOR 1.3 We did not have any interest rate derivatives that were designated as cash flow hedges of interest rate risk as of December 31, 2014. Non-designated Hedges Derivatives not designated as hedges are not speculative and are used to manage our exposure to interest rate movements and other identified risks, but do not meet the strict hedge accounting requirements of ASC 815 – “Derivatives and Hedging.” Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in our consolidated statements of operations. During the year ended December 31, 2015, we recorded losses of $698,000 related to non-designated hedges. As of December 31, 2015, we had the following outstanding non-designated hedges (notional amount in thousands): Non-designated Hedges Number of Notional Interest Rate Caps 4 C$ 67,303 Interest Rate Caps 1 $ 13,387 Buy GBP / Sell EUR Forward 1 € 12,857 Buy GBP / Sell USD Forward 1 £ 10,400 Buy USD / Sell GBP Forward 1 £ 10,400 Buy CAD / Sell USD Forward 1 C$ 1,000 Buy USD / Sell CAD Forward 1 C$ 1,000 We did not have any non-designated hedges outstanding as of December 31, 2014. Valuation of Derivative Instruments The following table summarizes the fair value of our derivative financial instruments ($ in thousands): Fair Value of Derivatives in an (1) Fair Value of Derivatives in a (2) December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 Derivatives designated as Foreign exchange contracts $ 7,999 $ 1,138 $ 511 $ — Interest rate caps 238 — — — Total derivatives designated as hedging instruments $ 8,237 $ 1,138 $ 511 $ — Derivatives not designated as hedging instruments: Foreign exchange contracts $ 419 $ — $ 937 $ — Interest rate caps 1 — — — Total derivatives not designated as hedging instruments $ 420 $ — $ 937 $ — Total Derivatives $ 8,657 $ 1,138 $ 1,448 $ — (1) Included in other assets in our consolidated balance sheets. (2) Included in accounts payable, accrued expenses, and 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): Derivatives in Hedging Relationships Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Location of Gain (Loss) OCI into Income (Effective Portion) Amount of Gain (Loss) Reclassified from Year Ended December 31, Year Ended December 31, 2015 2014 2013 2015 2014 2013 Net Investment Foreign exchange contracts (1) $ 25,356 $ 1,138 $ — Interest Expense $ — $ — $ — Cash Flow Hedges Interest rate caps contracts (2) (1,474 ) — — Interest Expense (4 ) — — Total $ 23,882 $ 1,138 $ — $ (4 ) $ — $ — (1) During the year ended December 31, 2015, we received net cash settlements of $18.8 million on our foreign currency forward contracts. Those amounts are included as a component of accumulated other comprehensive loss on our consolidated balance sheets. We did not receive net cash settlements on our foreign currency contracts during 2014 and 2013. (2) During 2013, our consolidated subsidiary, CT Legacy Partners, was party to five interest rate swaps. In June 2013, CT Legacy Partners terminated these interest rate swaps and recorded a gain of $136,000 which was included as a component of interest expense on our consolidated statements of operations for the year ended December 31, 2013. CT Legacy Partners was no longer party to any derivative financial instruments subsequent to December 31, 2013. 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 December 31, 2015, we were in a net asset position with both of our derivative counterparties.

Equity

Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Equity	10. EQUITY Stock and Stock Equivalents Authorized Capital As of December 31, 2015, 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 December 31, 2015. 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. The following table details our issuance of class A common stock during the year ended December 31, 2015 ($ in thousands, except share and per share data): Class A Common Stock Offerings 2015 Total / Wtd.-Avg. April 2015 May 2015 (1) June 2015 Shares issued 23,000,000 280,025 11,500,000 34,780,025 Share issue price (2) $ 29.75 $ 29.97 $ 29.42 $ 29.64 Net proceeds (3) $ 683,722 $ 7,895 $ 337,918 $ 1,029,535 (1) Issuance represents 280,025 shares issued over a five-day period in May 2015 under our at-the-market program. (2) Represents price per share paid by the underwriters or sales agents, as applicable. (3) Net proceeds represents proceeds received from the underwriters less applicable transaction costs. The following table details our issuance of class A common stock during the year ended December 31, 2014 ($ in thousands, except share and per share data): Class A Common Stock Offerings 2014 Total / Wtd.-Avg. January 2014 April 2014 September 2014 December 2014 (1) Shares Issued 9,775,000 9,200,000 9,200,000 100,000 28,275,000 Issue Price (2) $ 26.25 $ 27.72 $ 27.49 $ 27.58 $ 27.14 Net Proceeds (3) $ 256,092 $ 254,758 $ 252,530 $ 2,758 $ 766,138 (1) Issuance represents 100,000 shares issued over a five-day period in December under our at-the-market program. (2) Represents price per share paid to the underwriters or sales agents, as applicable. (3) Net proceeds represents proceeds received from the underwriters less applicable transaction costs. We also issue restricted class A common stock under our stock-based incentive plans. Refer to Note 13 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: Year Ended December 31, Common Stock Outstanding (1) 2015 2014 Beginning balance 58,388,808 29,602,884 Issuance of class A common stock 34,780,622 28,275,006 Issuance of restricted class A common stock, net 651,815 490,381 Issuance of deferred stock units 22,602 20,537 Ending balance 93,843,847 58,388,808 (1) Deferred stock units held by members of our board of directors totaled 141,521 and 118,919 as of December 31, 2015 and 2014, 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 years ended December 31, 2015 and 2014, we issued 597 shares and six shares, respectively, of class A common stock under the dividend reinvestment component of the plan. As of December 31, 2015, a total of 9,999,397 shares of class A common stock remain 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. 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. During the years ended December 31, 2015 and 2014, we sold 280,025 shares and 100,000 shares, respectively, of class A common stock under the ATM Agreements, with net proceeds totaling $7.9 million and $2.8 million, respectively. As of December 31, 2015, sales of our class A common stock with an aggregate sales price of $188.6 million remain 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 December 14, 2015, we declared a dividend of $0.62 per share, or $58.1 million, which was paid on January 15, 2016, to stockholders of record as of December 31, 2015. The follow table details our dividend activity ($ in thousands, except per share data): Year Ended December 31, 2015 2014 2013 Dividends declared per share of common stock $ 2.28 $ 1.98 $ 0.72 Percent taxable as ordinary dividends 92.36 % 99.52 % 100.00 % Percent taxable as capital gain dividends 7.64 % 0.48 % 0.00 % 100.0 % 100.0 % 100.0 % 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): Year Ended December 31, 2015 2014 2013 Net income (1) $ 196,829 $ 90,045 $ 15,032 Weighted-average shares outstanding, basic and diluted 81,740,227 48,394,478 18,520,052 Per share amount, basic and diluted $ 2.41 $ 1.86 $ 0.81 (1) Represents net income attributable to Blackstone Mortgage Trust, Inc. Other Balance Sheet Items Accumulated Other Comprehensive Loss As of December 31, 2015, total accumulated other comprehensive loss was $32.8 million, primarily representing (i) $57.8 million of cumulative currency translation adjustment on assets and liabilities denominated in foreign currencies and (ii) an offsetting $25.0 million gain related to changes in the fair value of derivative instruments. As of December 31, 2014, total accumulated other comprehensive loss was $15.0 million, primarily representing the cumulative currency translation adjustments on assets and liabilities denominated in a foreign currency. Non-Controlling Interests The non-controlling interests included on our consolidated balance sheets represent the equity interests in CT Legacy Partners that are not owned by us. A portion of CT Legacy Partners’ consolidated equity and results of operations are allocated to these non-controlling interests based on their pro rata ownership of CT Legacy Partners. As of December 31, 2015, CT Legacy Partners’ total equity was $22.5 million, of which $9.4 million was owned by Blackstone Mortgage Trust, Inc., and $13.1 million was allocated to non-controlling interests. As of December 31, 2014, CT Legacy Partners’ total equity was $60.8 million, of which $25.3 million was owned by Blackstone Mortgage Trust, Inc., and $35.5 million was allocated to non-controlling interests.

Other Expenses

Other Expenses	12 Months Ended
	Dec. 31, 2015
Other Income and Expenses [Abstract]
Other Expenses	11. 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 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 (or the period since the date of the first offering of our class A common stock following December 19, 2012, whichever is shorter) 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 years ended December 31, 2015, 2014, and 2013, we incurred $32.2 million, $17.8 million, and $5.9 million of management fees payable to our Manager, respectively. In addition, during the years ended December 31, 2015 and 2014, we incurred $10.7 million and $1.7 million of incentive fees payable to our Manager, respectively. We did not incur any incentive fees payable to our Manager for the year ended December 31, 2013. As of December 31, 2015 we had accrued management and incentive fees payable to our Manager of $14.4 million, compared to $6.3 million as of December 31, 2014. General and Administrative Expenses General and administrative expenses consisted of the following ($ in thousands): Year Ended December 31, 2015 2014 2013 Professional services $ 3,156 $ 2,324 $ 1,889 Operating and other costs 2,709 1,980 1,762 GE transaction costs 9,623 — — Subtotal 15,488 4,304 3,651 Non-cash and CT Legacy Portfolio compensation expenses Management incentive awards plan—CTOPI (1) 5,370 12,898 — Management incentive awards plan—CT Legacy Partners (2) 2,177 1,374 5,089 Restricted class A common stock earned 12,966 7,988 1,064 Director stock-based compensation 375 375 263 Subtotal 20,888 22,635 6,416 Total BXMT expenses 36,376 26,939 10,067 Expenses of consolidated subsidiaries 333 860 1,438 Total general and administrative expenses $ 36,709 $ 27,799 $ 11,505 (1) Represents the portion of CTOPI promote revenue accrued under compensation awards. See Note 4 for further discussion. (2) Represents the accrual of amounts payable 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 CT Legacy Partners (subject to certain caps and priority distributions). Approximately 50% of the pool is 75% vested as of December 31, 2015, with the remainder contingent on continued employment with an affiliate of our Manager and our receipt of distributions from CT Legacy Partners. Of the remaining 50% of the pool, 27% is fully vested as a result of an acceleration event, and 23% vest only upon our receipt of distributions from CT Legacy Partners. We accrue a liability for the amounts due under these grants based on the value of CT Legacy Partners and the periodic vesting of the awards granted. Accrued payables for these awards were $1.3 million and $2.8 million as of December 31, 2015 and 2014, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	12. 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 December 31, 2015 and 2014, we were in compliance with all REIT requirements. During the years ended December 31, 2015, 2014, and 2013, we recorded a current income tax provision of $504,000, $518,000, and $995,000, respectively, primarily related to activities of our taxable REIT subsidiaries and various state and local taxes. We did not have any deferred tax assets or liabilities as of December 31, 2015 or 2014. As a result of our issuance of 25,875,000 shares of class A common stock in May 2013, the availability of our net operating losses, or NOLs, and net capital losses, or NCLs, 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, 2015, we had estimated NOLs of $159.0 million and NCLs of $602,000 available to be carried forward and utilized in current or future periods. If we are unable to utilize our NOLs, they will expire in 2029. If we are unable to utilize our NCLs, they will expire in 2017. As of December 31, 2015, tax years 2012 through 2015 remain subject to examination by taxing authorities.

Stock-Based Incentive Plans

Stock-Based Incentive Plans	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Incentive Plans	13. STOCK-BASED INCENTIVE PLANS We do not have any employees as we are externally managed by our Manager. However, as of December 31, 2015, 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 five benefit plans as of December 31, 2015: (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; and (v) our 2013 manager incentive plan, or 2013 Manager Plan. We refer to our 1997 Plan, our 2007 Plan, and our 2011 Plan collectively as our Expired Plans and we refer to our 2013 Plan and 2013 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 2,160,106 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 December 31, 2015, there were 264,902 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, 2013 700,000 $ 25.69 Granted 490,381 27.82 Vested (270,662 ) 25.57 Balance as of December 31, 2014 919,719 $ 26.86 Granted 679,958 28.25 Vested (456,626 ) 26.94 Forfeited (28,143 ) 28.28 Balance as of December 31, 2015 1,114,908 $ 27.64 These shares generally vest in quarterly installments over a three-year period, pursuant to the terms of the respective award agreements and the terms of the Current Plans. The 1,114,908 shares of restricted class A common stock outstanding as of December 31, 2015 will vest as follows: 567,705 shares will vest in 2016; 383,866 shares will vest in 2017; and 163,337 shares will vest in 2018. As of December 31, 2015, total unrecognized compensation cost relating to nonvested share-based compensation arrangements was $29.8 million. This cost is expected to be recognized over a weighted average period of 1.2 years from December 31, 2015.

Fair Values

Fair Values	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Values	14. 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): December 31, 2015 December 31, 2014 Level 1 Level 2 Level 3 Fair Value Level 1 Level 2 Level 3 Fair Value Assets Derivatives $ — $ 8,657 $ — $ 8,657 $ — $ 1,138 $ — $ 1,138 Other assets, at fair value (1) $ — $ 1,659 $ 12,561 $ 14,220 $ — $ 1,510 $ 47,507 $ 49,017 Liabilities Derivatives $ — $ 1,448 $ — $ 1,448 $ — $ — $ — $ — (1) Other assets include loans, securities, equity investments, and other receivables measured at fair value. 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): Year Ended December 31, 2015 2014 January 1, $ 47,507 $ 54,461 Proceeds from investment realizations (57,039 ) (20,231 ) Adjustments to fair value included in earnings Gain on investments at fair value 22,093 13,277 December 31, $ 12,561 $ 47,507 As of December 31, 2015, we had $12.6 million of assets measured using Level 3 inputs, which primarily consist of commercial mortgage backed securities that are valued using market quotes received from financial sources that trade such securities. Refer to Note 2 for further discussion regarding fair value measurement. Fair Value of Financial Instruments As discussed in Note 2, GAAP requires disclosure of fair value information about financial instruments, whether or not recognized in the statement of financial position, for which it is practicable to estimate that value. The following table details the carrying amount, face amount, and fair value of the financial instruments described in Note 2 ($ in thousands): December 31, 2015 December 31, 2014 Carrying Face Fair Carrying Face Fair Financial assets Cash and cash equivalents $ 96,450 $ 96,450 $ 96,450 $ 51,810 $ 51,810 $ 51,810 Restricted cash 9,556 9,556 9,556 11,591 11,591 11,591 Loans receivable, net 9,077,007 9,108,361 9,121,732 4,428,500 4,462,897 4,462,897 Financial liabilities Secured debt agreements 6,116,105 6,131,751 6,131,751 2,353,279 2,365,336 2,365,336 Loan participations sold 497,032 498,992 498,992 496,080 499,433 499,433 Convertible notes, net 164,026 172,500 171,344 161,455 172,500 181,341 Estimates of fair value for cash, cash equivalents and convertible notes are measured using observable, quoted market prices, or Level 1 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.

Transactions with Related Parti

Transactions with Related Parties	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Transactions with Related Parties	15. TRANSACTIONS WITH RELATED PARTIES We are managed by our Manager pursuant to a management agreement, the initial term of which expires on December 19, 2016 and will be automatically renewed for a one-year term each anniversary thereafter unless earlier terminated. The Management Agreement with our Manager excludes from the management fee calculation our interests in CT Legacy Partners and CTOPI. There may be conflicts between us and our Manager with respect to certain of the investments in the CT Legacy Partners and CTOPI portfolios where an affiliate of our Manager holds a related investment that is senior, junior, or pari passu On May 13, 2013, we entered into a joint venture, 42-16 Partners, with an affiliate of our Manager to originate and warehouse loans prior to the completion of our class A common stock offering on May 29, 2013. 42-16 Partners was owned 16.7% by us and 83.3% by an affiliate of our Manager and originated one senior mortgage loan on May 21, 2013. On May 30, 2013, we ended this relationship with the affiliate of our Manager and purchased 100% of the equity interests in 42-16 Partners held by the affiliate of our Manager using proceeds from the sale of our class A common stock, and, as a result, 42-16 Partners became a 100% owned and consolidated subsidiary. We recorded a $193,000 charge to non-controlling interest as a result of the purchase of these equity interests at their fair value, rather than GAAP book value. An affiliate of our Manager purchased 1,960,784 shares of our class A common stock as part of our stock offering on May 22, 2013. These shares were purchased for $25.50 each, the same price offered to non-affiliated purchasers. This affiliate owned class A common stock representing 4.7% of outstanding class A common stock and stock units as of February 9, 2016. In addition, an affiliate of our Manager was compensated $1.0 million for its role as co-manager of our offering of class A common stock on May 22, 2013 and $188,000 for its role as co-manager of our offering of convertible notes on November 19, 2013. On October 2, 2013 we originated a $71.0 million loan, the proceeds of which were used by the borrower to repay an existing loan owned by an affiliate of our Manager. On October 23, 2013, we purchased a $176.9 million loan from a third party. In conjunction with our acquisition of this loan, we consented to its restructuring, which restructuring resulted in an affiliate of our Manager earning a $2.3 million modification fee. During the years ended December 31, 2014 and 2013, a securitization vehicle previously consolidated in our financial statements incurred special servicing fees to our Manager of $522,000 and $847,000 respectively, of which it paid $139,000 and $847,000 respectively. On June 20, 2014, CT Legacy Partners, CTOPI, our previously consolidated CT CDO I subsidiary, and other affiliates of our Manager entered into a deed-in-lieu of foreclosure transaction which resulted in a restructuring of the loan interests held by each entity. The interests held by CT Legacy Partners and CT CDO I had a principal balance of $8.0 million and $27.0 million, respectively, and a carrying value of zero and $27.0 million, respectively, at the time of the transaction. During the fourth quarter of 2014, we fully impaired our interests in CT CDO I resulting in a loss on deconsolidation of $8.6 million. During the fourth quarter of 2015, the collateral property securing the interests held by these entities was sold, with no net proceeds to our investments in CT Legacy Partners and CT CDO I. As a result of the collateral sale transaction, an affiliate of our Manager earned a $1.1 million special servicing fee, which fee was not paid by us. In conjunction with our April 2015 stock offering, affiliates of our Manager, including certain of our executive officers and directors, purchased 1,885,245 shares of our class A common stock at the same $30.50 per share price offered to the public. We did not, however, pay the underwriters any fees for these affiliate share purchases. An affiliate of our Manager acted as co-manager of the offering, for which it was compensated $761,000 on terms consistent with those for other non-affiliated underwriters. On April 10, 2015, we entered into a memorandum of designation and understanding, or Designation Agreement, with GE and certain affiliates of our Manager to acquire a $4.6 billion portfolio of commercial mortgage loans from GE. Pursuant to the terms of the Designation Agreement, we were designated as the purchaser of this loan portfolio by an affiliate of our Manager that entered into a purchase and sale agreement dated as of April 10, 2015 with GE to acquire the majority of GE’s global real estate debt and equity business for an aggregate purchase price of approximately $23.0 billion. Certain transaction-related expenses incurred by us in connection with the acquisition of this loan portfolio represent an allocation of transaction expenses paid by affiliates of our Manager in connection with the overall acquisition transaction with GE. In August 2015, we paid an aggregate $53,000 to certain independent members of our board of directors for special committee services related to the GE portfolio acquisition. In March 2015, we originated a $320.0 million loan to a third party. In conjunction with the origination of our loan and repayment of the pre-exiting financing, an affiliate of our Manager earned a modification fee of $354,000. On May 8, 2015, a joint venture of CT Legacy Partners, certain affiliates of our Manager, and other non-affiliated parties, which we refer to as the Three-Pack JV, sold a hotel portfolio it owned to an investment vehicle managed by an affiliate of our Manager. We consented to the sale of the hotel portfolio by the Three-Pack JV, which resulted in the ultimate liquidation of the Three-Pack JV and distribution of net sale proceeds to CT Legacy Partners in respect of its investment therein. During the year ended December 31, 2015, we recognized a gain of $21.6 million on our consolidated statement of operations to reflect the $40.1 million of expected net sales proceeds to be received by CT Legacy Partners, of which $37.7 million has been received as of December 31, 2015. As a result of the sale transaction, employees of our Manager, including certain of our executive officers, will receive incentive compensation payments of an aggregate $2.7 million under the CT Legacy Partners Management Incentive Awards Plan, of which $2.5 million has already been paid, based on $40.1 million of net sale proceeds to CT Legacy Partners. See Note 11 for further discussion of the CT Legacy Partners Management Incentive Awards Plan. In May 2015, we originated a $590.0 million loan, the proceeds of which were used by the borrower to repay an existing loan owned by an affiliate of our Manager. As of December 31, 2015 and 2014, our consolidated balance sheet included $14.4 million and $6.3 million of accrued management and incentive fees payable to our Manager, respectively. During the years ended December 31, 2015, 2014, and 2013, we paid $34.8 million, $15.7 million and $3.4 million, respectively, of management and incentive fees to our Manager. In addition, during the years ended December 31, 2015 and 2014, we reimbursed our Manager for $311,000 and $115,000, respectively, of expenses incurred on our behalf. We did not make any such payment to our Manager during the year ended 2013. As of December 31, 2015, our consolidated balance sheet includes $83,333 of preferred distributions payable by CT Legacy Partners to an affiliate of our Manager, compared to $151,000 as of December 31, 2014. During the years ended December 31, 2015, 2014, and 2013, CT Legacy Partners made aggregate preferred distributions of $1.3 million, $2.1 million, $3.9 million, respectively, to such affiliate. During the years ended December 31, 2015, 2014, and 2013, we issued 334,758, 337,941, and 339,431 shares of restricted class A common stock to our Manager under the 2013 Manager Plan, which had a grant date fair value of $9.3 million, $9.4 million, and $8.5 million, respectively. The shares vest ratably in quarterly installments over three years from the date of issuance. During the years ended December 31, 2015, 2014, and 2013, we recorded non-cash expense related to these shares of $6.7 million, $3.8 million, and $767,000, respectively. Refer to Note 13 for further details. During the years ended December 31, 2015, 2014, and 2013, we incurred $372,000, $202,000, and $9,000, respectively, of expenses for various administrative and capital market data services to third-party service providers that are affiliates of our Manager. During the years ended December 31, 2014 and 2013, CT CDO I incurred special servicing fees to our Manager of $522,000 and $847,000, respectively. There were no CT CDO I special servicing fees incurred during the year ended December 31, 2015.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. COMMITMENTS AND CONTINGENCIES Unfunded Commitments Under Loans Receivable As of December 31, 2015, we had unfunded commitments of $700.7 million related to 69 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. Income Tax Audits of CTIMCO The Internal Revenue Service and the State of New York are separately undergoing examinations of the income tax returns for the years ended December 31, 2012 and 2011 of our former subsidiary, CT Investment Management Co., LLC, or CTIMCO. The examinations are on-going, and no adjustments have been communicated to us. When we sold CTIMCO in December 2012, we provided certain indemnifications related to its operations, and any amounts determined to be owed by CTIMCO would ultimately be paid by us. As of December 31, 2015, there were no reserves recorded for the CTIMCO examinations. Litigation From time to time, we may be involved in various claims and legal actions arising in the ordinary course of business. As of December 31, 2015, we were not involved in any material legal proceedings. Board of Directors’ Compensation As of December 31, 2015, of the eight members of our board of directors, our five independent directors are entitled to annual compensation of $125,000 each. The other three board members, including our chairman and our chief executive officer, serve as directors with no compensation. As of December 31, 2015, the annual compensation for our directors was paid 40% in cash and 60% in the form of deferred stock units. In addition, the member of our board of directors that serves as the chairperson of the audit committee of our board of directors receives additional annual cash compensation of $12,000. Compensation to the board of directors is payable in four equal quarterly installments.

Summary of Quarterly Results of

Summary of Quarterly Results of Operations	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations	17. SUMMARY OF QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) The following is a summary of the unaudited quarterly results of operations for the years ended December 31, 2015, 2014, and 2013 ($ in thousands except per share data): March 31 June 30 September 30 December 31 2015 Income from loans and other investments, net $ 39,246 $ 49,847 $ 87,032 $ 82,094 Net income $ 46,093 $ 32,417 $ 67,778 $ 65,597 Net income attributable to Blackstone Mortgage Trust, Inc. $ 35,393 $ 29,284 $ 66,888 $ 65,264 Net income per share of class A common stock: Basic and diluted $ 0.60 $ 0.36 $ 0.72 $ 0.70 2014 Income from loans and other investments, net $ 21,582 $ 26,746 $ 30,483 $ 36,812 Net income $ 13,116 $ 38,439 $ 23,601 $ 25,338 Net income attributable to Blackstone Mortgage Trust, Inc. $ 13,065 $ 33,466 $ 22,024 $ 21,490 Net income per share of class A common stock: Basic and diluted $ 0.34 $ 0.70 $ 0.45 $ 0.37 Basic and diluted earnings per share are computed independently based on the weighted-average shares of common stock and stock units outstanding for each period. Accordingly, the sum of the quarterly earnings per share amounts may not agree to the total for the year. Earnings per share amounts have been adjusted to give retroactive effect to the reverse stock split, which we effected on May 6, 2013. See Note 10 for a further discussion of earnings per share.

Schedule IV - Mortgage Loans on

Schedule IV - Mortgage Loans on Real Estate	12 Months Ended
	Dec. 31, 2015
Mortgage Loans on Real Estate [Abstract]
Schedule IV - Mortgage Loans on Real Estate	Schedule IV – Mortgage Loans on Real Estate As of December 31, 2015 (in thousands) Type of Loan/Borrower Description / Location Interest Payment Rates Maximum (2) Periodic (3) Prior Liens (4) Face Amount Carrying (5) Senior Mortgage Loans (1) Senior loans in excess of 3% of the carrying amount of total loans Borrower A MHC / Diversified-US 4.89 % (6) 2019 I/O & P/I $ — $ 338,565 $ 339,613 Borrower B MHC / Diversified-US 5.29 % (6) 2016 I/O & P/I — 304,710 306,152 Borrower C Hotel / U.K. L+4.00 % 2019 I/O — 296,320 293,192 Borrower D Office / Northeast L+3.45 % 2020 I/O — 294,500 292,061 Borrower E Office / Northeast L+3.50 % 2020 I/O — 274,878 272,632 Senior loans less than 3% of the carrying amount of total loans Senior mortgage loans Office / Diversified L+2.30% – 5.50 % 2016 – 2020 I/O & P/I — 3,567,658 3,550,802 Fixed 4.46% – 6.48 % Senior mortgage loans Hotel / Diversified L+3.25% – 4.50 % 2016 – 2021 I/O & P/I — 1,603,592 1,600,332 Fixed 5.30% – 6.08 % Senior mortgage loans MHC / Diversified L+1.75% – 5.00 % 2016 – 2021 I/O & P/I — 715,857 715,806 Fixed 4.67% – 6.30 % Senior mortgage loans Retail / Diversified L+3.10% – 4.50 % 2017 – 2019 I/O & P/I — 610,163 608,275 Fixed 5.14% – 5.38 % Senior mortgage loans Multifamily / Diversified L+3.40% – 4.50 % 2017 – 2025 I/O & P/I — 542,376 540,184 Fixed 4.28% – 6.03 % Senior mortgage loans Condo / Northeast L+3.75 % 2017 – 2019 I/O & P/I — 84,096 83,920 Senior mortgage loans Other / Diversified L+3.30% – 5.00 % 2016 – 2019 I/O & P/I — 242,801 244,076 Fixed 4.63% – 6.22 % — 7,366,543 7,343,395 Total senior mortgage loans $ — $ 8,875,516 $ 8,847,045 Subordinate Loans (7) Subordinate loans less than 3% of the carrying amount of total loans Subordinate loans Various / Diversified L+10.75% – 12.83 % 2019 – 2022 I/O 1,039,765 232,845 229,962 Fixed 12.22 % Total subordinate loans 1,039,765 232,845 229,962 Total loans $ 1,039,765 $ 9,108,361 $ 9,077,007 (1) Includes senior mortgages and similar credit quality loans, including related contiguous subordinate loans, and pari passu participations in senior mortgage loans. (2) Maximum maturity date assumes all extension options are exercised. (3) I/O = interest only, P/I = principal and interest. (4) Represents only third party liens. (5) The tax basis of the loans included above is $8.6 billion as of December 31, 2015. (6) Loan consists of one or more floating and fixed rate tranches. Coupon assumes applicable floating benchmark rate for weighted-average calculation. (7) Includes subordinate interests in mortgages and mezzanine loans. Blackstone Mortgage Trust, Inc. Notes to Schedule IV As of December 31, 2015 (in thousands) 1. Reconciliation of Mortgage Loans on Real Estate: The following table reconciles mortgage loans on real estate for the years ended: 2015 2014 2013 Balance at January 1, $ 4,428,500 $ 2,047,223 $ 141,500 Additions during period: Loan fundings 7,203,145 3,067,263 2,327,914 Amortization of deferred fees and expenses 36,052 19,785 5,965 Unrealized gain on foreign currency translation — — 796 Valuation allowance on loans held-for-sale — — 1,259 Deductions during period: Collections of principal (2,407,920 ) (564,183 ) (383,647 ) Unrealized loss on foreign currency translation (149,269 ) (52,076 ) — Deferred origination fees and expenses (33,501 ) (35,449 ) (25,402 ) Loans sold — (27,063 ) (21,162 ) Transfers to other assets — (27,000 ) — Balance at December 31, $ 9,077,007 $ 4,428,500 $ 2,047,223

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, and 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. Certain of the assets and credit of our consolidated subsidiaries are not available to satisfy the debt or other obligations of us, our affiliates, or other entities. One of our subsidiaries, CT Legacy Partners, LLC, or CT Legacy Partners, accounts for its operations in accordance with industry-specific GAAP accounting guidance for investment companies, pursuant to which it reports its investments at fair value. We have retained this accounting treatment in consolidation and, accordingly, report the loans and other investments of CT Legacy Partners at fair value on our consolidated balance sheets. Certain reclassifications have been made in the presentation of the prior period consolidated financial statements to conform to the current period presentation.
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. As of both December 31, 2015 and 2014, we did not consolidate any VIEs.
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 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 and Cash Equivalents	Cash and Cash Equivalents 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	Restricted Cash We classify the cash balances held by CT Legacy Partners as restricted because, while these cash balances are available for use by CT Legacy Partners for its operations, they cannot be used by us until our allocable share is distributed from CT Legacy Partners and cannot be commingled with any of our unrestricted cash balances.
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 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 will accrete 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 Investments in Unconsolidated Subsidiaries	Equity Investments in Unconsolidated Subsidiaries Our carried interest in CT Opportunity Partners I, LP, or CTOPI, is accounted for using the equity method. CTOPI’s assets and liabilities are not consolidated into our financial statements due to our determination that (i) it is not a VIE and (ii) the other investors in CTOPI have sufficient rights to preclude consolidation by us. As such, we report our allocable percentage of the net assets of CTOPI on our consolidated balance sheets. The recognition of income from CTOPI is generally deferred until cash is collected or appropriate contingencies have been eliminated.
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 freestanding derivative. For all derivatives other than those designated as freestanding derivatives, we formally document our hedge relationships and designation at 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. Changes in the fair value of the effective portion of our hedges are reflected in accumulated other comprehensive income (loss) on our consolidated financial statements. Changes in the fair value of the ineffective portion of our hedges are included in net income. Amounts are reclassified out of accumulated other comprehensive income (loss) and into net income when the hedged item is either sold or substantially liquidated. To the extent a derivative does not qualify for hedge accounting and is deemed a freestanding derivative, the changes in its value are included in net income.
Repurchase Agreements	Repurchase Agreements 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.
Loan Participations Sold	Loan Participations Sold Loan participations sold represent senior interests in certain loans that we sold, however we present such loan participations sold as liabilities because these arrangements do not qualify as sales under GAAP. These participations are non-recourse and remain on our consolidated balance sheet until the loan is repaid. The gross presentation of loan participations sold does not impact stockholders’ equity or net income.
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 issuance date based on our nonconvertible debt borrowing rate. The equity component of the 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 the 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 the 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 14. 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 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 on deposit and in money market funds approximates fair value. • Restricted cash: The carrying amount of restricted cash approximates fair value. • Loans receivable, net: The fair values for these loans were estimated by our Manager based on discounted cash flow methodology taking into consideration 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 contracts and interest rates caps was valued using advice from a third party derivative specialist, based on contractual cash flows and observable inputs comprising foreign currency rates and credit spreads. • Repurchase obligations: The fair values for these instruments were estimated based on the rate at which a similar credit facility would have currently priced. • Convertible notes, net: The convertible notes are actively traded and their fair values were obtained using quoted market prices for these instruments. • Loan participations sold: The fair value of these instruments were estimated based on the value of the related loan receivable asset.
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 12 for additional information.
Stock-Based Compensation	Stock-Based Compensation Our stock-based compensation consists of awards issued to our Manager and certain of its employees 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 13 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 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 class A common stock, including restricted class A common stock and deferred stock units. Refer to Note 10 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.
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.
Segment Reporting	Segment Reporting We previously operated our business through two segments, the Loan Origination segment and the CT Legacy Portfolio segment. In the first quarter of 2015, as a result of asset resolutions in our CT Legacy Portfolio, our Manager determined that the CT Legacy Portfolio segment was no longer a distinct and separately managed business. Accordingly, we no longer present segment reporting.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2015, the FASB issued ASU 2015-03, “Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs,” or ASU 2015-03. ASU 2015-03 simplifies the presentation of debt issuance costs by amending the accounting guidance to require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability. The amendments presented in ASU 2015-03 are consistent with the accounting guidance related to debt discounts. We adopted ASU 2015-03 in the fourth quarter of 2015 and applied its provisions retrospectively. This resulted in the reclassification of unamortized deferred financing costs from other assets to reductions in secured debt agreements, loan participations sold, and convertible notes of $12.1 million, $3.4 million, and $398,000, respectively, on our consolidated balance sheet as of December 31, 2014. Other than this reclassification, the adoption of this standard did not have an impact on our consolidated financial statements. In February 2015, the FASB issued ASU 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis,” or ASU 2015-02. ASU 2015-02 amends the guidance related to accounting for the consolidation of certain legal entities. The modifications made in ASU 2015-02 impact limited partnerships and similar legal entities, the evaluation of (i) fees paid to a decision maker or a service provider as a variable interest, (ii) fee arrangements, and (iii) related parties on the primary beneficiary determination. ASU 2015-02 is effective for the first interim or annual period beginning after December 15, 2015. We adopted ASU 2015-02 in the second quarter of 2015 and the adoption of this standard did not have a material impact on our consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, “Presentation of Financial Statements – Going Concern (Subtopic 2015-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” or ASU 2014-15. ASU 2014-15 introduces an explicit requirement for management to assess and provide certain disclosures if there is substantial doubt about an entity’s ability to continue as a going concern. ASU 2014-15 is effective for the annual period ending after December 15, 2016. We do not anticipate that the adoption of ASU 2014-15 will have a material impact on our consolidated financial statements. In June 2014, the FASB issued ASU 2014-11, “Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures,” or ASU 2014-11. ASU 2014-11 amends the accounting guidance for repurchase-to-maturity transactions and repurchase agreements executed as repurchase financings, and requires additional disclosure about certain transactions by the transferor. ASU 2014-11 is effective for certain transactions that qualify for sales treatment for the first interim or annual period beginning after December 15, 2014. The new disclosure requirements for repurchase agreements, securities lending transactions, and repurchase-to-maturity transactions that qualify for secured borrowing treatment is effective for annual periods beginning after December 15, 2014, and for interim periods beginning after March 15, 2015. We have historically recorded our repurchase arrangements as secured borrowings and, accordingly, the adoption of ASU 2014-11 did not have a material impact on our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606) ,

Loans Receivable (Tables)

Loans Receivable (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Overall Statistics for Loans Receivable Portfolio	The following table details overall statistics for our loans receivable portfolio as of December 31, 2015 ($ in thousands): Floating Rate Fixed Rate Total Number of loans 92 33 125 Principal balance $ 7,098,180 $ 2,010,181 $ 9,108,361 Net book value $ 7,064,279 $ 2,012,728 $ 9,077,007 Unfunded loan commitments (1) $ 696,276 $ 4,382 $ 700,658 Weighted-average cash coupon (2) L+4.09 % 5.63 % 4.84 % Weighted-average all-in yield (2) L+4.49 % 5.78 % 5.18 % Weighted-average maximum maturity (years) (3) 3.3 2.6 3.1 (1) Unfunded commitments will primarily be funded to finance property improvements or lease-related expenditures by the borrowers. These future commitments will expire over the next four years. (2) As of December 31, 2015, our floating rate loans were indexed to various benchmark rates, with 84% of floating rate loans indexed to USD LIBOR. In addition, $147.9 million of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 1.80%, as of December 31, 2015. In addition to cash coupon, all-in yield includes the amortization of deferred origination fees, loan origination costs, purchase discounts, and accrual of both extension and exit fees. Cash coupon and all-in yield for the total portfolio assume applicable floating benchmark rate for weighted-average calculation. (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of December 31, 2015, 64% of our loans were subject to yield maintenance or other prepayment restrictions and 36% were open to repayment by the borrower without penalty. As of December 31, 2014, our loan portfolio was 100% comprised of floating rate loans. The following table details overall statistics for our loans receivable portfolio as of December 31, 2014 ($ in thousands): December 31, 2014 Number of loans 60 Principal balance $ 4,462,897 Net book value $ 4,428,500 Unfunded loan commitments (1) $ 513,229 Weighted-average cash coupon (2) L+4.36 % Weighted-average all-in yield (2) L+4.81 % Weighted-average maximum maturity (years) (3) 3.9 (1) Unfunded commitments will primarily be funded to finance property improvements or lease-related expenditures by the borrowers. These future commitments will expire over the next four years. (2) As of December 31, 2014, all of our loans were floating rate loans and were indexed to various benchmark rates, with 79% of floating rate loans indexed to USD LIBOR. In addition, 14% of our floating rate loans earned interest based on floors that are above the applicable index, with an average floor of 0.31%, as of December 31, 2014. In addition to cash coupon, all-in yield includes the amortization of deferred origination fees, loan origination costs, and accrual of both extension and exit fees. (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of December 31, 2014, 85% of our loans were subject to yield maintenance or other prepayment restrictions and 15% 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 Balance Deferred Fees / (1) Net Book Value December 31, 2013 $ 2,077,227 $ (30,004 ) $ 2,047,223 Loan originations, acquisitions, and fundings 3,067,263 — 3,067,263 Loan repayments (591,246 ) — (591,246 ) Unrealized (loss) gain on foreign currency translation (52,801 ) 725 (52,076 ) Deferred fees and other items (1) — (35,449 ) (35,449 ) Amortization of fees and other items (1) — 19,785 19,785 Charge-offs (2) (10,546 ) 10,546 — Reclassification to other assets (27,000 ) — (27,000 ) December 31, 2014 $ 4,462,897 $ (34,397 ) $ 4,428,500 Loan originations, acquisitions, and fundings 7,203,145 — 7,203,145 Loan repayments (2,407,920 ) — (2,407,920 ) Unrealized (loss) gain on foreign currency translation (149,761 ) 492 (149,269 ) Deferred fees and other items (1) — (33,501 ) (33,501 ) Amortization of fees and other items (1) — 36,052 36,052 December 31, 2015 $ 9,108,361 $ (31,354 ) $ 9,077,007 (1) Other items primarily consist of purchase discounts or premiums, exit fees, and deferred origination expenses. (2) Represents the charge off of a loan held by CT Legacy Partners that was fully reserved in a prior year.
Types of Loans in Loan Portfolio, as well as Property Type and Geographic Distribution of Properties Securing these Loans	The tables below detail the types of loans in our loan portfolio, as well as the property type and geographic distribution of the properties securing these loans ($ in thousands): December 31, 2015 December 31, 2014 Asset Type Net Book Value Percentage Net Book Value Percentage Senior loans (1) $ 8,847,044 97 % $ 4,340,586 98 % Subordinate loans (2) 229,963 3 87,914 2 $ 9,077,007 100 % $ 4,428,500 100 % Property Type Net Book Value Percentage Net Book Value Percentage Office $ 4,039,521 45 % $ 1,878,605 42 % Hotel 1,903,544 21 1,267,486 29 Manufactured housing 1,361,572 15 — — Retail 684,944 8 270,812 6 Multifamily 580,112 6 426,094 10 Condominium 127,434 1 315,686 7 Other 379,880 4 269,817 6 $ 9,077,007 100 % $ 4,428,500 100 % Geographic Location Net Book Value Percentage Net Book Value Percentage United States Northeast $ 2,260,392 25 % $ 1,383,258 31 % Southeast 1,836,766 20 657,484 15 West 1,125,238 12 628,275 14 Southwest 1,035,839 11 405,741 9 Midwest 616,964 7 335,406 8 Northwest 390,307 4 138,796 3 Subtotal 7,265,506 79 3,548,960 80 International United Kingdom 888,998 10 622,692 14 Canada 561,023 6 137,024 3 Germany 235,294 3 — — Spain 66,661 1 86,289 2 Netherlands 59,525 1 33,535 1 Subtotal 1,811,501 21 879,540 20 Total $ 9,077,007 100 % $ 4,428,500 100 % (1) Includes senior mortgages and similar credit quality loans, including related contiguous subordinate loans, and pari passu participations in senior mortgage loans. (2) Includes mezzanine loans and subordinate interests in mortgages.
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): December 31, 2015 December 31, 2014 Risk Rating Number Principal Net Book Value Number Principal Net Book Value 1 12 $ 925,443 $ 919,991 5 $ 209,961 $ 209,112 2 77 5,948,922 5,929,447 44 3,339,972 3,313,906 3 35 2,120,713 2,114,531 11 912,964 905,482 4 1 113,283 113,038 — — — 5 — — — — — — 125 $ 9,108,361 $ 9,077,007 60 $ 4,462,897 $ 4,428,500

Equity Investments in Unconso28

Equity Investments in Unconsolidated Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Activity Relating to Our Equity Investments in Unconsolidated Subsidiaries	As of December 31, 2015 and 2014, our equity investments in unconsolidated subsidiaries consisted solely of our carried interest in CTOPI, a fund sponsored and managed by an affiliate of our Manager. Activity relating to our equity investments in unconsolidated subsidiaries was ($ in thousands): CTOPI Total as of December 31, 2013 $ 22,480 Distributions (17,867 ) Deferred income allocation (1) 5,991 Total as of December 31, 2014 $ 10,604 Distributions (5,007 ) Income allocation (1) 3,844 Total as of December 31, 2015 $ 9,441 (1) In instances where we have not received cash or all appropriate contingencies have not been eliminated, we have deferred the recognition of promote revenue allocated to us from CTOPI in respect of our carried interest in CTOPI, and recorded an offsetting liability as a component of accounts payable, accrued expenses, and other liabilities on our consolidated balance sheets.

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Components of Other Assets	The following table details the components of our other assets ($ in thousands): December 31, December 31, Principal and interest payments held by servicer (1) $ 123,160 $ — Accrued interest receivable 37,161 17,240 Real estate debt and equity investments, at fair value (2) 14,220 49,017 Prepaid expenses 890 948 Prepaid taxes 525 534 Other 8,163 2,469 Total $ 184,119 $ 70,208 (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. (2) Real estate debt and equity investments consists of assets held by CT Legacy Partners and are measured at fair value.

Secured Debt Agreements (Tables

Secured Debt Agreements (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Secured Debt Agreements	The following table details our secured debt agreements ($ in thousands): Secured Debt Agreements Borrowings Outstanding December 31, 2015 December 31, 2014 Revolving repurchase facilities $ 2,858,714 $ 2,040,783 GE portfolio acquisition facility 3,161,291 — Asset-specific repurchase agreements 111,746 324,553 Total secured debt agreements $ 6,131,751 $ 2,365,336 Deferred financing costs (1) (15,646 ) (12,057 ) Net book value of secured debt $ 6,116,105 $ 2,353,279 (1) Costs incurred in connection with our secured debt agreements are recorded on our consolidated balance sheet when paid and recognized as a component of interest expense over the life of each related agreement.
Revolving Repurchase Facilities	The following table details our revolving repurchase facilities ($ in thousands): December 31, 2015 Maximum Facility Size (1) Collateral Assets (2) Repurchase Borrowings Lender Potential (3) Outstanding Available (3) Wells Fargo (4) $ 1,172,000 $ 1,044,860 $ 817,562 $ 685,485 $ 132,077 Bank of America 750,000 840,884 665,861 618,944 46,917 JP Morgan (5) 787,047 864,630 689,705 596,533 93,172 Citibank (6) 537,500 604,781 461,532 370,194 91,338 MetLife 750,000 593,273 462,849 324,587 138,262 Morgan Stanley (7) 370,400 273,280 212,050 209,038 3,012 Société Générale (8) 437,320 67,416 53,933 53,933 — $ 4,804,267 $ 4,289,124 $ 3,363,492 $ 2,858,714 $ 504,778 December 31, 2014 Maximum Facility Size (1) Collateral Assets (2) Repurchase Borrowings Lender Potential (3) Outstanding Available (3) Wells Fargo (4) $ 1,000,000 $ 747,256 $ 585,737 $ 484,365 $ 101,372 Citibank (6) 500,000 621,025 472,080 392,455 79,625 Bank of America 500,000 557,810 441,201 389,347 51,854 JP Morgan (5) 488,155 544,654 422,249 341,487 80,762 MetLife 500,000 476,499 366,902 305,889 61,013 Morgan Stanley (7) 389,050 174,297 137,181 127,240 9,941 $ 3,377,205 $ 3,121,541 $ 2,425,350 $ 2,040,783 $ 384,567 (1) Maximum facility size represents the total amount of borrowings in each repurchase agreement, however these borrowings are only available to us once sufficient collateral assets have been pledged under each facility at the discretion of the lender. (2) Represents the principal balance of the collateral assets. (3) Potential borrowings represent 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 revolving credit facility. (4) The Wells Fargo maximum facility size is composed of a $1.0 billion facility and $172.0 million related solely to a specific asset with a repurchase date of July 30, 2016, compared to a $1.0 billion facility as of December 31, 2014. (5) As of December 31, 2015 the JP Morgan maximum facility size was composed of a $250.0 million facility, a £153.0 million ($226.7 million) facility, $262.5 million related solely to a specific asset with a repurchase date of January 9, 2018, and additional capacity of £32.3 million ($47.8 million) on the £153.0 million facility to be depleted as pledged assets repay, compared to a $250.0 million facility and a £153.0 million ($238.2 million) facility as of December 31, 2014. (6) As of December 31, 2015, the Citibank maximum facility size was composed of a $500.0 million facility and $37.5 million related solely to a specific asset with a repurchase date of October 9, 2017, compared to a $500.0 million facility as of December 31, 2014. (7) As of December 31, 2015 the Morgan Stanley maximum facility size represents a £250.0 million ($370.4 million) facility, compared to a £250.0 million ($389.1 million) facility as of December 31, 2014. (8) The Société Générale maximum facility size represents a €400.0 million ($437.3 million) facility.
Summary of Key Terms of Revolving Repurchase Facilities	The following table outlines the key terms of our revolving repurchase facilities as of December 31, 2015: Lender Rate (1)(2) Guarantee (3) Advance Rate (1) Margin Call (4) Term/Maturity Wells Fargo L+1.78 % 25 % 79.4 % Collateral marks only Term matched (5) Bank of America L+1.69 % 50 % 79.5 % Collateral marks only May 21, 2019 (6) JP Morgan L+1.82 % 25 % 80.4 % Collateral marks only Term matched (5)(7) Citibank L+1.92 % 25 % 77.7 % Collateral marks only Term matched (5) MetLife L+1.75 % 50 % 78.1 % Collateral marks only February 24, 2021 (8) Morgan Stanley L+2.35 % 25 % 78.7 % Collateral marks only March 3, 2017 Société Générale L+1.60 % 25 % 80.0 % Collateral marks only July 13, 2018 (9) (1) Represents a weighted-average based on borrowings outstanding and collateral assets pledged as of December 31, 2015. (2) Represents weighted-average cash coupon on borrowings outstanding as of December 31, 2015. As of December 31, 2015, our floating rate loans and related liabilities were indexed to the various benchmark rates relevant in each case 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. (3) Other than amounts guaranteed based on specific collateral asset types, borrowings under our revolving repurchase facilities are non-recourse to us. (4) Margin call provisions under our revolving repurchase facilities do not permit valuation adjustments based on capital markets activity, and are limited to collateral-specific credit marks. (5) These revolving repurchase 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. (6) Includes two one-year extension options which may be exercised at our sole discretion. (7) Borrowings denominated in British pound sterling under this facility mature on January 7, 2018. (8) Includes five one-year extension options which may be exercised at our sole discretion. (9) Includes a one-year extension option which, subject to certain provisions, may be exercised at our discretion.
Summary of Statistics for Asset-Specific Repurchase Agreements	The following table details statistics for our asset-specific repurchase agreements ($ in thousands): December 31, 2015 December 31, 2014 Repurchase Collateral Repurchase Collateral Number of loans 2 2 3 4 Principal balance $ 111,746 $ 154,192 $ 324,553 $ 429,197 Book value $ 111,061 $ 153,542 $ 321,347 $ 425,680 Weighted-average cash coupon (1) L+2.52 % L+5.27 % L+2.68 % L+5.07 % Weighted-average cost / all-in yield (1) L+2.88 % L+5.83 % L+3.16 % L+5.53 % (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, cost / all-in yield includes the amortization of deferred origination fees / financing costs.

Loan Participations Sold (Table

Loan Participations Sold (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Summary of Statistics for Loan Participations Sold	The following table details statistics for our loan participations sold ($ in thousands): December 31, 2015 December 31, 2014 Participations (1) Underlying Participations (1) Underlying Number of loans 3 3 4 4 Principal balance (2) $ 498,992 $ 608,554 $ 499,433 $ 635,701 Book value (2) $ 497,032 $ 604,321 $ 496,080 $ 628,745 Weighted-average cash coupon (3) L+2.38 % L+3.93 % L+2.51 % L+4.10 % Weighted-average cost / all-in yield (3) L+2.49 % L+4.15 % L+2.71 % L+4.71 % (1) During the years ended December 31, 2015 and 2014, we recorded $18.3 million and $12.4 million, respectively, of interest expense related to our loan participations sold, of which $16.9 million and $11.7 million, respectively, was paid in cash. (2) The difference between principal balance and book value of loan participations sold is due to deferred financing costs of $2.0 million and $3.4 million as of December 31, 2015 and 2014, respectively. (3) Our floating rate loans and related liabilities were 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, all-in cost / yield includes the amortization of deferred origination fees / financing costs.

Derivative Financial Instrume32

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
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): December 31, 2015 December 31, 2014 Foreign Currency Number of Notional Amount Foreign Currency Number of Notional Amount Sell CAD Forward 2 C$ 154,900 Sell CAD Forward 1 C$ 42,525 Sell GBP Forward 2 £ 90,400 Sell EUR Forward 1 € 49,000
Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk	As of December 31, 2015, we had the following outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk (notional amount in thousands): Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Caps 26 $ 1,097,632 2 % USD LIBOR 1.3 Interest Rate Caps 7 C 483,286 2 % CDOR 1.2 Interest Rate Caps 1 € 152,710 2 % EURIBOR 1.0 Interest Rate Caps 1 £ 15,142 2 % GBP LIBOR 1.3
Summary of Outstanding Non-designated Hedges	As of December 31, 2015, we had the following outstanding non-designated hedges (notional amount in thousands): Non-designated Hedges Number of Notional Interest Rate Caps 4 C$ 67,303 Interest Rate Caps 1 $ 13,387 Buy GBP / Sell EUR Forward 1 € 12,857 Buy GBP / Sell USD Forward 1 £ 10,400 Buy USD / Sell GBP Forward 1 £ 10,400 Buy CAD / Sell USD Forward 1 C$ 1,000 Buy USD / Sell CAD Forward 1 C$ 1,000
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 (1) Fair Value of Derivatives in a (2) December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 Derivatives designated as Foreign exchange contracts $ 7,999 $ 1,138 $ 511 $ — Interest rate caps 238 — — — Total derivatives designated as hedging instruments $ 8,237 $ 1,138 $ 511 $ — Derivatives not designated as hedging instruments: Foreign exchange contracts $ 419 $ — $ 937 $ — Interest rate caps 1 — — — Total derivatives not designated as hedging instruments $ 420 $ — $ 937 $ — Total Derivatives $ 8,657 $ 1,138 $ 1,448 $ — (1) Included in other assets in our consolidated balance sheets. (2) Included in accounts payable, accrued expenses, and 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): Derivatives in Hedging Relationships Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Location of Gain (Loss) OCI into Income (Effective Portion) Amount of Gain (Loss) Reclassified from Year Ended December 31, Year Ended December 31, 2015 2014 2013 2015 2014 2013 Net Investment Foreign exchange contracts (1) $ 25,356 $ 1,138 $ — Interest Expense $ — $ — $ — Cash Flow Hedges Interest rate caps contracts (2) (1,474 ) — — Interest Expense (4 ) — — Total $ 23,882 $ 1,138 $ — $ (4 ) $ — $ — (1) During the year ended December 31, 2015, we received net cash settlements of $18.8 million on our foreign currency forward contracts. Those amounts are included as a component of accumulated other comprehensive loss on our consolidated balance sheets. We did not receive net cash settlements on our foreign currency contracts during 2014 and 2013. (2) During 2013, our consolidated subsidiary, CT Legacy Partners, was party to five interest rate swaps. In June 2013, CT Legacy Partners terminated these interest rate swaps and recorded a gain of $136,000 which was included as a component of interest expense on our consolidated statements of operations for the year ended December 31, 2013. CT Legacy Partners was no longer party to any derivative financial instruments subsequent to December 31, 2013.

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Class A Common Stock Issuances	The following table details our issuance of class A common stock during the year ended December 31, 2015 ($ in thousands, except share and per share data): Class A Common Stock Offerings 2015 Total / Wtd.-Avg. April 2015 May 2015 (1) June 2015 Shares issued 23,000,000 280,025 11,500,000 34,780,025 Share issue price (2) $ 29.75 $ 29.97 $ 29.42 $ 29.64 Net proceeds (3) $ 683,722 $ 7,895 $ 337,918 $ 1,029,535 (1) Issuance represents 280,025 shares issued over a five-day period in May 2015 under our at-the-market program. (2) Represents price per share paid by the underwriters or sales agents, as applicable. (3) Net proceeds represents proceeds received from the underwriters less applicable transaction costs. The following table details our issuance of class A common stock during the year ended December 31, 2014 ($ in thousands, except share and per share data): Class A Common Stock Offerings 2014 Total / Wtd.-Avg. January 2014 April 2014 September 2014 December 2014 (1) Shares Issued 9,775,000 9,200,000 9,200,000 100,000 28,275,000 Issue Price (2) $ 26.25 $ 27.72 $ 27.49 $ 27.58 $ 27.14 Net Proceeds (3) $ 256,092 $ 254,758 $ 252,530 $ 2,758 $ 766,138 (1) Issuance represents 100,000 shares issued over a five-day period in December under our at-the-market program. (2) Represents price per share paid to the underwriters or sales agents, as applicable. (3) Net proceeds represents proceeds received from the underwriters less applicable transaction costs.
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: Year Ended December 31, Common Stock Outstanding (1) 2015 2014 Beginning balance 58,388,808 29,602,884 Issuance of class A common stock 34,780,622 28,275,006 Issuance of restricted class A common stock, net 651,815 490,381 Issuance of deferred stock units 22,602 20,537 Ending balance 93,843,847 58,388,808 (1) Deferred stock units held by members of our board of directors totaled 141,521 and 118,919 as of December 31, 2015 and 2014, respectively.
Schedule of Dividend Activity	The follow table details our dividend activity ($ in thousands, except per share data): Year Ended December 31, 2015 2014 2013 Dividends declared per share of common stock $ 2.28 $ 1.98 $ 0.72 Percent taxable as ordinary dividends 92.36 % 99.52 % 100.00 % Percent taxable as capital gain dividends 7.64 % 0.48 % 0.00 % 100.0 % 100.0 % 100.0 %
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): Year Ended December 31, 2015 2014 2013 Net income (1) $ 196,829 $ 90,045 $ 15,032 Weighted-average shares outstanding, basic and diluted 81,740,227 48,394,478 18,520,052 Per share amount, basic and diluted $ 2.41 $ 1.86 $ 0.81 (1) Represents net income attributable to Blackstone Mortgage Trust, Inc.

Other Expenses (Tables)

Other Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Other Income and Expenses [Abstract]
Schedule of General and Administrative Expenses	General and administrative expenses consisted of the following ($ in thousands): Year Ended December 31, 2015 2014 2013 Professional services $ 3,156 $ 2,324 $ 1,889 Operating and other costs 2,709 1,980 1,762 GE transaction costs 9,623 — — Subtotal 15,488 4,304 3,651 Non-cash and CT Legacy Portfolio compensation expenses Management incentive awards plan—CTOPI (1) 5,370 12,898 — Management incentive awards plan—CT Legacy Partners (2) 2,177 1,374 5,089 Restricted class A common stock earned 12,966 7,988 1,064 Director stock-based compensation 375 375 263 Subtotal 20,888 22,635 6,416 Total BXMT expenses 36,376 26,939 10,067 Expenses of consolidated subsidiaries 333 860 1,438 Total general and administrative expenses $ 36,709 $ 27,799 $ 11,505 (1) Represents the portion of CTOPI promote revenue accrued under compensation awards. See Note 4 for further discussion. (2) Represents the accrual of amounts payable 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)	12 Months Ended
	Dec. 31, 2015
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, 2013 700,000 $ 25.69 Granted 490,381 27.82 Vested (270,662 ) 25.57 Balance as of December 31, 2014 919,719 $ 26.86 Granted 679,958 28.25 Vested (456,626 ) 26.94 Forfeited (28,143 ) 28.28 Balance as of December 31, 2015 1,114,908 $ 27.64

Fair Values (Tables)

Fair Values (Tables)	12 Months Ended
	Dec. 31, 2015
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): December 31, 2015 December 31, 2014 Level 1 Level 2 Level 3 Fair Value Level 1 Level 2 Level 3 Fair Value Assets Derivatives $ — $ 8,657 $ — $ 8,657 $ — $ 1,138 $ — $ 1,138 Other assets, at fair value (1) $ — $ 1,659 $ 12,561 $ 14,220 $ — $ 1,510 $ 47,507 $ 49,017 Liabilities Derivatives $ — $ 1,448 $ — $ 1,448 $ — $ — $ — $ — (1) Other assets include loans, securities, equity investments, and other receivables measured at fair value.
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): Year Ended December 31, 2015 2014 January 1, $ 47,507 $ 54,461 Proceeds from investment realizations (57,039 ) (20,231 ) Adjustments to fair value included in earnings Gain on investments at fair value 22,093 13,277 December 31, $ 12,561 $ 47,507
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): December 31, 2015 December 31, 2014 Carrying Face Fair Carrying Face Fair Financial assets Cash and cash equivalents $ 96,450 $ 96,450 $ 96,450 $ 51,810 $ 51,810 $ 51,810 Restricted cash 9,556 9,556 9,556 11,591 11,591 11,591 Loans receivable, net 9,077,007 9,108,361 9,121,732 4,428,500 4,462,897 4,462,897 Financial liabilities Secured debt agreements 6,116,105 6,131,751 6,131,751 2,353,279 2,365,336 2,365,336 Loan participations sold 497,032 498,992 498,992 496,080 499,433 499,433 Convertible notes, net 164,026 172,500 171,344 161,455 172,500 181,341

Summary of Quarterly Results 37

Summary of Quarterly Results of Operations (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations	The following is a summary of the unaudited quarterly results of operations for the years ended December 31, 2015, 2014, and 2013 ($ in thousands except per share data): March 31 June 30 September 30 December 31 2015 Income from loans and other investments, net $ 39,246 $ 49,847 $ 87,032 $ 82,094 Net income $ 46,093 $ 32,417 $ 67,778 $ 65,597 Net income attributable to Blackstone Mortgage Trust, Inc. $ 35,393 $ 29,284 $ 66,888 $ 65,264 Net income per share of class A common stock: Basic and diluted $ 0.60 $ 0.36 $ 0.72 $ 0.70 2014 Income from loans and other investments, net $ 21,582 $ 26,746 $ 30,483 $ 36,812 Net income $ 13,116 $ 38,439 $ 23,601 $ 25,338 Net income attributable to Blackstone Mortgage Trust, Inc. $ 13,065 $ 33,466 $ 22,024 $ 21,490 Net income per share of class A common stock: Basic and diluted $ 0.34 $ 0.70 $ 0.45 $ 0.37

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)Segment	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount attributable to consolidated VIEs	$ 0		$ 0
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
Number of operating segment | Segment	2
General Electrical Capital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase price of Loan Portfolio		$ 4,700,000,000
Secured Debt Agreements [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized deferred financing costs			12,100,000
Loan Participations Sold [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized deferred financing costs			3,400,000
Convertible Notes [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized deferred financing costs			$ 398,000

Loans Receivable - Additional I

Loans Receivable - Additional Information (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Apr. 10, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio		100.00%
Impaired loans	$ 0	$ 0
Loans in maturity default		$ 0		$ 113,000,000
Maturity date			Feb. 29, 2016
Loan Purchase Commitments [Member] | Commercial Portfolio Segment [Member] | General Electrical Capital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio of loans acquired						$ 4,600,000,000
Loans originated and acquired			$ 7,500,000,000
Loans funded			$ 221,100,000
Unfunded Loan Commitment [Member] | Commercial Portfolio Segment [Member] | General Electrical Capital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio of loans acquired					$ 4,900,000,000

Loans Receivable - Overall Stat

Loans Receivable - Overall Statistics for Loans Receivable Portfolio (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)SecurityLoan	Dec. 31, 2014USD ($)SecurityLoan	Dec. 31, 2013USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 9,077,007	$ 4,428,500
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	125	60
Principal Balance	$ 9,108,361	$ 4,462,897	$ 2,077,227
Net book value	9,077,007	4,428,500
Unfunded loan commitments	$ 700,658	$ 513,229
Weighted-average maximum maturity (years)	3 years 1 month 6 days	3 years 10 months 24 days
Loans Receivable [Member] | LIBOR [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average cash coupon, rate	4.84%	4.36%
Weighted-average all-in yield, rate	5.18%	4.81%
Floating Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	92
Principal Balance	$ 7,098,180
Net book value	7,064,279
Unfunded loan commitments	$ 696,276
Weighted-average cash coupon	L+4.09 %
Weighted-average all-in yield	L+4.49 %
Weighted-average maximum maturity (years)	3 years 3 months 18 days
Floating Rate [Member] | LIBOR [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average cash coupon, rate	4.09%
Weighted-average all-in yield, rate	4.49%
Fixed Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	33
Principal Balance	$ 2,010,181
Net book value	2,012,728
Unfunded loan commitments	$ 4,382
Weighted-average maximum maturity (years)	2 years 7 months 6 days
Fixed Rate [Member] | LIBOR [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average cash coupon, rate	5.63%
Weighted-average all-in yield, rate	5.78%

Loans Receivable - Overall St41

Loans Receivable - Overall Statistics for Loans Receivable Portfolio (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitments expiration period	4 years	4 years
Percentage of loans receivable by type		14.00%
Floating rate loans	$ 147.9
Average floor rate	1.80%	0.31%
Percentage of loans subject to yield maintenance, or other prepayment restrictions	64.00%	85.00%
Percentage of loans open to repayment by borrower without penalty	36.00%	15.00%
USD LIBOR [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loans receivable by type	84.00%	79.00%

Loans Receivable - Activity Rel

Loans Receivable - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	$ 4,428,500
Loan originations, acquisitions, and fundings	7,203,145	$ 3,067,263	$ 2,327,914
Amortization of fees and other items	(36,052)	(19,785)	(5,965)
Reclassification to other assets		(27,000)
Ending Balance	9,077,007	4,428,500
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	4,428,500	2,047,223
Loan originations, acquisitions, and fundings	7,203,145	3,067,263
Loan repayments	(2,407,920)	(591,246)
Unrealized (loss) gain on foreign currency translation	(149,269)	(52,076)
Deferred fees and other items	33,501	35,449
Amortization of fees and other items	36,052	19,785
Reclassification to other assets		(27,000)
Ending Balance	9,077,007	4,428,500	2,047,223
Deferred Fees/Other Items [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	(34,397)	(30,004)
Unrealized (loss) gain on foreign currency translation	492	725
Deferred fees and other items	(33,501)	(35,449)
Amortization of fees and other items	36,052	19,785
Charge-offs		10,546
Ending Balance	(31,354)	(34,397)	(30,004)
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	4,462,897	2,077,227
Beginning Balance	4,428,500
Loan originations, acquisitions, and fundings	7,203,145	3,067,263
Loan repayments	(2,407,920)	(591,246)
Unrealized (loss) gain on foreign currency translation	(149,761)	(52,801)
Charge-offs		10,546
Reclassification to other assets		(27,000)
Ending Balance	9,108,361	4,462,897	$ 2,077,227
Ending Balance	$ 9,077,007	$ 4,428,500

Loans Receivable - Types of Loa

Loans Receivable - Types of Loans in Loan Portfolio, as well as Property Type and Geographic Distribution of Properties Securing these Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 9,077,007	$ 4,428,500
Percentage of Book Value	100.00%	100.00%
Senior Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 8,847,044	$ 4,340,586
Percentage of Book Value	97.00%	98.00%
Subordinate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 229,963	$ 87,914
Percentage of Book Value	3.00%	2.00%
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 9,077,007	$ 4,428,500
Percentage of Book Value	100.00%	100.00%
Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 4,039,521	$ 1,878,605
Percentage of Book Value	45.00%	42.00%
Hotel [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 1,903,544	$ 1,267,486
Percentage of Book Value	21.00%	29.00%
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 580,112	$ 426,094
Percentage of Book Value	6.00%	10.00%
Condominium [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 127,434	$ 315,686
Percentage of Book Value	1.00%	7.00%
Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 684,944	$ 270,812
Percentage of Book Value	8.00%	6.00%
Manufactured Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 1,361,572
Percentage of Book Value	15.00%
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 379,880	$ 269,817
Percentage of Book Value	4.00%	6.00%
United States Northeast [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 2,260,392	$ 1,383,258
Percentage of Book Value	25.00%	31.00%
United States Southeast [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 1,836,766	$ 657,484
Percentage of Book Value	20.00%	15.00%
United States West [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 1,125,238	$ 628,275
Percentage of Book Value	12.00%	14.00%
United States Southwest [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 1,035,839	$ 405,741
Percentage of Book Value	11.00%	9.00%
United States Midwest [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 616,964	$ 335,406
Percentage of Book Value	7.00%	8.00%
United States Northwest [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 390,307	$ 138,796
Percentage of Book Value	4.00%	3.00%
United States [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 7,265,506	$ 3,548,960
Percentage of Book Value	79.00%	80.00%
United Kingdom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 888,998	$ 622,692
Percentage of Book Value	10.00%	14.00%
Canada [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 561,023	$ 137,024
Percentage of Book Value	6.00%	3.00%
Spain [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 66,661	$ 86,289
Percentage of Book Value	1.00%	2.00%
Netherlands [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 59,525	$ 33,535
Percentage of Book Value	1.00%	1.00%
Germany [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 235,294
Percentage of Book Value	3.00%
International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 1,811,501	$ 879,540
Percentage of Book Value	21.00%	20.00%

Loans Receivable - Principal Ba

Loans Receivable - Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)SecurityLoan	Dec. 31, 2014USD ($)SecurityLoan	Dec. 31, 2013USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	$ 9,077,007	$ 4,428,500
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	125	60
Principal Balance	$ 9,108,361	$ 4,462,897	$ 2,077,227
Net book value	$ 9,077,007	$ 4,428,500
Risk Rating 1 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	12	5
Principal Balance	$ 925,443	$ 209,961
Net book value	$ 919,991	$ 209,112
Risk Rating 2 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	77	44
Principal Balance	$ 5,948,922	$ 3,339,972
Net book value	$ 5,929,447	$ 3,313,906
Risk Rating 3 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	35	11
Principal Balance	$ 2,120,713	$ 912,964
Net book value	$ 2,114,531	$ 905,482
Risk Rating 4 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	1
Principal Balance	$ 113,283
Net book value	$ 113,038

Equity Investments in Unconso45

Equity Investments in Unconsolidated Subsidiaries - Activity Relating to Our Equity Investments in Unconsolidated Subsidiaries (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Beginning Balance	$ 10,604,000
Distributions	(5,007,000)	$ (17,867,000)	$ (8,795,000)
Ending Balance	9,441,000	10,604,000
CT Opportunity Partners I, LP [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	10,604,000	22,480,000
Distributions	(5,007,000)	(17,867,000)	0
Deferred income allocation	3,844,000	5,991,000
Ending Balance	$ 9,441,000	$ 10,604,000	$ 22,480,000

Equity Investments in Unconso46

Equity Investments in Unconsolidated Subsidiaries - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2011
Schedule of Equity Method Investments [Line Items]
Promote income recognized	$ 5,007,000	$ 17,867,000	$ 8,795,000
CT Opportunity Partners I, LP [Member]
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%
Carried interest revenue	$ 9,400,000
Promote income recognized	$ 5,007,000	17,867,000	0
Percentage of carried interest distributions pool for employees				45.00%
Percentage of pool vested	68.00%
Fully vested pool, percentage	32.00%
Description of incentive management fee grants to employees vesting schedule	Approximately 68% of the pool is two-thirds vested as of December 31, 2015, with the remainder contingent on continued employment with an affiliate of our Manager and upon our receipt of promote distributions from CTOPI. The remaining 32% of the pool is fully vested as a result of an acceleration event. During the year ended December 31, 2015, we accrued $2.6 million under the CTOPI incentive plan compared to $11.2 million for the year ended December 31, 2014 and [$2.8 million] for the year ended December 31, 2013, which amounts were recognized as a component of general and administrative expenses in our consolidated statement of operations.
CT Opportunity Partners I, LP [Member] | CTOPI Incentive Plan [Member]
Schedule of Equity Method Investments [Line Items]
Accrued expenses for incentive plan	$ 5,400,000	$ 12,900,000	$ 0

Other Assets - Summary of Compo

Other Assets - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Principal and interest payments held by servicer	$ 123,160
Accrued interest receivable	37,161	$ 17,240
Real estate debt and equity investments, at fair value	14,220	49,017
Prepaid expenses	890	948
Prepaid taxes	525	534
Other	8,163	2,469
Total	$ 184,119	$ 70,208

Secured Debt Agreements - Sched

Secured Debt Agreements - Schedule of Secured Debt Agreements (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	$ 6,131,751	$ 2,365,336
Deferred financing costs	(15,646)	(12,057)
Net book value of secured debt	6,116,105	2,353,279
Revolving Repurchase Facilities [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	2,858,714	2,040,783
GE Portfolio Acquisition Facility [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	3,161,291
Asset-Specific Repurchase Agreements [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	111,746	324,553
Net book value of secured debt	$ 111,061	$ 321,347

Secured Debt Agreements - Addit

Secured Debt Agreements - Additional Information (Detail)	Dec. 31, 2015USD ($)	Jun. 30, 2015USD ($)ExtensionOptions	Dec. 31, 2015USD ($)FacilityAssets	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Approximate credit line, outstanding amount			$ 256,000,000
Maturity date			Feb. 29, 2016
Secured debt agreements borrowings outstanding	$ 6,116,105,000		$ 6,116,105,000	$ 2,353,279,000
Covenants, minimum tangible net worth	$ 1,900,000,000		$ 1,900,000,000
Covenants, percentage of tangible assets on cash proceeds from equity issuances			75.00%
Covenants, percentage of recourse indebtedness	5.00%		5.00%
Maximum [Member]
Debt Instrument [Line Items]
Covenants, EBITDA to fixed charges, in percent			1.40%
Covenants, indebtedness to total assets, in percent	83.33%		83.33%
Minimum [Member]
Debt Instrument [Line Items]
Covenants, EBITDA to fixed charges, in percent			1.00%
Covenants, minimum cash liquidity amount	$ 10,000,000		$ 10,000,000
Asset-Specific Repurchase Agreements [Member]
Debt Instrument [Line Items]
Additional credit capacity			103,100,000
Weighted-average outstanding balance			$ 340,200,000	257,900,000
Closing of asset specific repurchase facilities | Assets			1
GE Portfolio Acquisition Facility [Member] | Sequential Repay Advance [Member]
Debt Instrument [Line Items]
Term of maturity date		1 year
Secured debt agreements borrowings outstanding	40,700,000		$ 40,700,000
Current borrowing capacity		$ 237,200,000
Percentage of additional advance		5.00%
Sequential Repay Advance, percentage of guarantee rate		100.00%
GE Portfolio Acquisition Facility [Member] | Wells Fargo [Member]
Debt Instrument [Line Items]
Approximate credit line amount	3,300,000,000		3,300,000,000
Approximate credit line, outstanding amount	3,200,000,000
Amount available for potential future fundings of loan	142,600,000		$ 142,600,000
GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member]
Debt Instrument [Line Items]
Weighted average rate		80.00%
Maturity date			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.
Number of extension options | ExtensionOptions		2
Term of maturity date		1 year
Secured debt agreements borrowings outstanding	3,100,000,000		$ 3,100,000,000
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
Revolving Repurchase Facilities [Member]
Debt Instrument [Line Items]
Number of revolving repurchase facilities closed | Facility			5
Additional credit capacity			$ 1,500,000,000
Weighted-average outstanding balance			2,500,000,000	1,400,000,000
Aggregate borrowings	2,900,000,000		$ 2,900,000,000	$ 2,000,000,000
Weighted-average advance rate			79.14%
Weighted-average initial maturity			1 year 4 months 24 days	1 year 9 months 18 days
Approximate credit line amount	4,804,267,000		$ 4,804,267,000	$ 3,377,205,000
Amount available for potential future fundings of loan	504,778,000		504,778,000	384,567,000
Current borrowing capacity	3,363,492,000		$ 3,363,492,000	2,425,350,000
Revolving Repurchase Facilities [Member] | Wells Fargo [Member]
Debt Instrument [Line Items]
Debt instrument variable rate basis			L+1.78 %
Weighted-average advance rate			79.40%
Approximate credit line amount	1,172,000,000		$ 1,172,000,000	1,000,000,000
Amount available for potential future fundings of loan	132,077,000		$ 132,077,000	101,372,000
Borrowings maturity term			Term matched
Current borrowing capacity	$ 817,562,000		$ 817,562,000	$ 585,737,000
LIBOR [Member] | GE Portfolio Acquisition Facility [Member] | Sequential Repay Advance [Member]
Debt Instrument [Line Items]
Debt instrument variable rate basis			Accrue interest at a rate equal to the sum of (i) 30-day LIBOR plus (ii) a margin of 3.10%.
LIBOR basis spread on debt obligation, in percent		3.10%
LIBOR [Member] | Revolving Repurchase Facilities [Member] | Wells Fargo [Member]
Debt Instrument [Line Items]
LIBOR basis spread on debt obligation, in percent			1.78%
Weighted-Average Cash Coupon [Member] | Revolving Repurchase Facilities [Member]
Debt Instrument [Line Items]
Debt instrument variable rate basis			LIBOR plus 1.82% per annum
LIBOR basis spread on debt obligation, in percent			1.82%	1.88%
Weighted-Average All-in Cost of Credit [Member] | Revolving Repurchase Facilities [Member]
Debt Instrument [Line Items]
Debt instrument variable rate basis			LIBOR plus 2.04% per annum
LIBOR basis spread on debt obligation, in percent			2.04%	2.11%
Base Rate [Member] | GE Portfolio Acquisition Facility [Member] | Asset Specific Borrowings [Member] | Primary [Member]
Debt Instrument [Line Items]
Debt instrument variable rate basis			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.
LIBOR 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]
LIBOR 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]
LIBOR basis spread on debt obligation, in percent		1.85%

Secured Debt Agreements - Revol

Secured Debt Agreements - Revolving Repurchase Facilities (Detail) - Revolving Repurchase Facilities [Member]	Dec. 31, 2015USD ($)	Dec. 31, 2015GBP (£)	Dec. 31, 2014USD ($)	Dec. 31, 2014GBP (£)
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 4,804,267,000		$ 3,377,205,000
Collateral Assets	4,289,124,000		3,121,541,000
Potential	3,363,492,000		2,425,350,000
Repurchase Borrowings Outstanding	2,858,714,000		2,040,783,000
Available	504,778,000		384,567,000
Wells Fargo [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	1,172,000,000		1,000,000,000
Collateral Assets	1,044,860,000		747,256,000
Potential	817,562,000		585,737,000
Repurchase Borrowings Outstanding	685,485,000		484,365,000
Available	132,077,000		101,372,000
Bank of America [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	750,000,000		500,000,000
Collateral Assets	840,884,000		557,810,000
Potential	665,861,000		441,201,000
Repurchase Borrowings Outstanding	618,944,000		389,347,000
Available	46,917,000		51,854,000
JP Morgan [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	787,047,000		488,155,000
Collateral Assets	864,630,000		544,654,000
Potential	689,705,000		422,249,000
Repurchase Borrowings Outstanding	596,533,000		341,487,000
Available	93,172,000		80,762,000
Citibank [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	537,500,000		500,000,000
Collateral Assets	604,781,000		621,025,000
Potential	461,532,000		472,080,000
Repurchase Borrowings Outstanding	370,194,000		392,455,000
Available	91,338,000		79,625,000
MetLife [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	750,000,000		500,000,000
Collateral Assets	593,273,000		476,499,000
Potential	462,849,000		366,902,000
Repurchase Borrowings Outstanding	324,587,000		305,889,000
Available	138,262,000		61,013,000
Morgan Stanley [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	370,400,000	£ 250,000,000	389,050,000	£ 250,000,000
Collateral Assets	273,280,000		174,297,000
Potential	212,050,000		137,181,000
Repurchase Borrowings Outstanding	209,038,000		127,240,000
Available	3,012,000		$ 9,941,000
Societe Generale [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	437,320,000	£ 400,000,000
Collateral Assets	67,416,000
Potential	53,933,000
Repurchase Borrowings Outstanding	$ 53,933,000

Secured Debt Agreements - Rev51

Secured Debt Agreements - Revolving Repurchase Facilities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2015GBP (£)	Dec. 31, 2014USD ($)	Dec. 31, 2014GBP (£)
Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 4,804,267,000		$ 3,377,205,000
Wells Fargo [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	1,172,000,000		1,000,000,000
Wells Fargo [Member] | Asset Specific Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 172,000,000
Facility repurchase date	Jul. 30, 2016
JP Morgan [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 787,047,000		488,155,000
JP Morgan [Member] | Asset Specific Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 262,500,000
Facility repurchase date	Jan. 9, 2018
JP Morgan [Member] | Pledged Assets Repayment Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 47,800,000	£ 32,300,000
Citibank [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	537,500,000		500,000,000
Citibank [Member] | Asset Specific Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 37,500,000
Facility repurchase date	Oct. 9, 2017
Morgan Stanley [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 370,400,000	250,000,000	389,050,000	£ 250,000,000
Societe Generale [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	437,320,000	400,000,000
$250.0 Million Facility [Member] | JP Morgan [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	250,000,000		250,000,000
UK Pound Sterling153.0 Million ($226.7 Million) Facility [Member] | JP Morgan [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	226,700,000	£ 153,000,000	238,200,000	£ 153,000,000
$500.0 Million Facility [Member] | Citibank [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000		500,000,000
$1.0 Billion Facility [Member] | Wells Fargo [Member] | Revolving Repurchase Facilities [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 1,000,000,000		$ 1,000,000,000

Secured Debt Agreements - Summa

Secured Debt Agreements - Summary of Key Terms of Revolving Repurchase Facilities (Detail) - Revolving Repurchase Facilities [Member]	12 Months Ended
	Dec. 31, 2015
Line of Credit Facility [Line Items]
Advance Rate	79.14%
Wells Fargo [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+1.78 %
Guarantee	25.00%
Advance Rate	79.40%
Margin Call	Collateral marks only
Term/Maturity	Term matched
Wells Fargo [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	1.78%
Bank of America [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+1.69 %
Guarantee	50.00%
Advance Rate	79.50%
Margin Call	Collateral marks only
Term/Maturity	May 21, 2019
Bank of America [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	1.69%
JP Morgan [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+1.82 %
Guarantee	25.00%
Advance Rate	80.40%
Margin Call	Collateral marks only
Term/Maturity	Term matched
JP Morgan [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	1.82%
Citibank [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+1.92 %
Guarantee	25.00%
Advance Rate	77.70%
Margin Call	Collateral marks only
Term/Maturity	Term matched
Citibank [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	1.92%
MetLife [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+1.75 %
Guarantee	50.00%
Advance Rate	78.10%
Margin Call	Collateral marks only
Term/Maturity	February 24, 2021
MetLife [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	1.75%
Morgan Stanley [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+2.35 %
Guarantee	25.00%
Advance Rate	78.70%
Margin Call	Collateral marks only
Term/Maturity	March 3, 2017
Morgan Stanley [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	2.35%
Societe Generale [Member]
Line of Credit Facility [Line Items]
Debt instrument variable rate basis	L+1.60 %
Guarantee	25.00%
Advance Rate	80.00%
Margin Call	Collateral marks only
Term/Maturity	July 13, 2018
Societe Generale [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Rate	1.60%

Secured Debt Agreements - Sum53

Secured Debt Agreements - Summary of Key Terms of Revolving Repurchase Facilities (Parenthetical) (Detail) - Revolving Repurchase Facilities [Member]	12 Months Ended
	Dec. 31, 2015ExtensionOptions
Line of Credit Facility [Line Items]
Facility mature date	Jan. 7, 2018
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
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
Societe Generale [Member]
Line of Credit Facility [Line Items]
Maturity period	Includes a one-year extension option which, subject to certain provisions, may be exercised at our discretion.
Number of extension options	1
Term of maturity date	1 year

Secured Debt Agreements - Sum54

Secured Debt Agreements - Summary of Statistics for Asset-Specific Repurchase Agreements (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)Loans	Dec. 31, 2014USD ($)Loans
Participating Mortgage Loans [Line Items]
Book value	$ 6,116,105	$ 2,353,279
Collateral Assets [Member]
Participating Mortgage Loans [Line Items]
Number of loans | Loans	2	4
Principal balance	$ 154,192	$ 429,197
Book value	$ 153,542	$ 425,680
Collateral Assets [Member] | Weighted-Average Cash Coupon [Member]
Participating Mortgage Loans [Line Items]
Debt instrument variable rate basis	L+5.27 %
Weighted-average cash coupon, Basis spread on variable rate	5.27%	5.07%
Collateral Assets [Member] | Weighted-Average All-in Cost of Credit [Member]
Participating Mortgage Loans [Line Items]
Debt instrument variable rate basis	L+5.83 %
Weighted-average cost / all-in yield, rate	5.83%	5.53%
Asset-Specific Repurchase Agreements [Member]
Participating Mortgage Loans [Line Items]
Number of loans | Loans	2	3
Principal balance	$ 111,746	$ 324,553
Book value	$ 111,061	$ 321,347
Asset-Specific Repurchase Agreements [Member] | Weighted-Average Cash Coupon [Member]
Participating Mortgage Loans [Line Items]
Debt instrument variable rate basis	L+2.52 %
Weighted-average cash coupon, Basis spread on variable rate	2.52%	2.68%
Asset-Specific Repurchase Agreements [Member] | Weighted-Average All-in Cost of Credit [Member]
Participating Mortgage Loans [Line Items]
Debt instrument variable rate basis	L+2.88 %
Weighted-average cost / all-in yield, rate	2.88%	3.16%

Loan Participations Sold - Addi

Loan Participations Sold - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)Participants
Debt Disclosure [Abstract]
Number of senior loan participation sold | Participants	1
Proceeds from line of credit	$ 256
Guarantor obligations	$ 35.6

Loan Participations Sold - Summ

Loan Participations Sold - Summary of Statistics for Loan Participations Sold (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)Loans	Dec. 31, 2014USD ($)Loans
Participating Mortgage Loans [Line Items]
Participations Sold, Number of loans | Loans	3	4
Principal balance, Participations Sold	$ 498,992	$ 499,433
Book value, Participations Sold	$ 497,032	$ 496,080
Weighted-average cash coupon, Participations Sold	L+2.38 %
Weighted-average all-in cost / yield, Participations Sold	L+2.49 %
Underlying Loans, Number of loans | Loans	3	4
Principal balance, Underlying Loans	$ 608,554	$ 635,701
Book value, Underlying Loans	$ 604,321	$ 628,745
Weighted-average cash coupon, Underlying Loans	L+3.93 %	L+4.10 %
Weighted-average all-in cost / yield, Underlying Loans	L+4.15 %	L+4.71 %
LIBOR [Member]
Participating Mortgage Loans [Line Items]
Weighted-average cash coupon, Participations Sold, rate	2.38%	2.51%
Weighted-average all-in cost / yield, Participations Sold	2.49%	2.71%
Weighted-average cash coupon, Underlying Loans, rate	3.93%	4.10%
Weighted-average all-in cost / yield, Underlying Loans	4.15%	4.71%

Loan Participations Sold - Su57

Loan Participations Sold - Summary of Statistics for Loan Participations Sold (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Participating Mortgage Loans [Line Items]
Interest paid	$ 127,429	$ 55,174	$ 12,702
Deferred financing costs	15,646	12,057
Loan Participations Sold [Member]
Participating Mortgage Loans [Line Items]
Interest expense	18,300	12,400
Interest paid	16,900	11,700
Deferred financing costs	$ 2,000	$ 3,400

Convertible Notes, Net - Additi

Convertible Notes, Net - Additional Information (Detail)	1 Months Ended	3 Months Ended	12 Months Ended
	Nov. 30, 2013USD ($)$ / shares	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Debt Instrument [Line Items]
Maturity date			Feb. 29, 2016
Convertible notes, net		$ 164,026,000	$ 164,026,000	$ 161,455,000
Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Senior Notes, Principal amount	$ 172,500,000
Convertible Senior Notes, Interest rate	5.25%
Maturity date			Dec. 1, 2018
Convertible Senior Notes, Interest rate including underwriter discounts	5.87%
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, at the applicable conversion rate in effect on the conversion date.
Discount upon issuance of Convertible Notes	$ 9,100,000	8,200,000	$ 8,200,000
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%
Total interest on convertible notes			11,600,000	11,500,000	$ 1,100,000
Interest on convertible notes related to cash coupon			9,100,000	9,100,000	874,000
Interest on convertible notes related to amortization of discount and certain issuance costs			2,500,000	2,400,000	$ 197,000
Accrued interest payable		755,000	755,000	$ 755,000
Deferred financing costs		$ 305,000	305,000
Convertible Senior Notes [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, common stock issued, in percent	34.8943	35.2653
Convertible Notes, debt conversion, principal amount	$ 1,000	$ 1,000	$ 0
Debt instrument, conversion price | $ / shares	$ 28.36	$ 26.76	$ 26.76

Derivative Financial Instrume59

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	Dec. 31, 2015GBP (£)DerivativeInstrument	Dec. 31, 2015CADDerivativeInstrument	Dec. 31, 2015EUR (€)DerivativeInstrument	Dec. 31, 2014CADDerivativeInstrument
EUR [Member]
Derivative [Line Items]
Number of Instruments	1	1	1
Notional Amount | €			€ 49,000
GBP [Member]
Derivative [Line Items]
Number of Instruments	2	2	2
Notional Amount | £	£ 90,400
CAD [Member]
Derivative [Line Items]
Number of Instruments	2	2	2	1
Notional Amount | CAD		CAD 154,900		CAD 42,525

Derivative Financial Instrume60

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives recorded losses during the period	$ 698,000
Interest Rate Caps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cash flow hedge ineffectiveness	0	$ 0	$ 0
Reclassification from other accumulated comprehensive income as increase to interest expense	$ 780,000

Derivative Financial Instrume61

Derivative Financial Instruments - Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk (Detail) - 12 months ended Dec. 31, 2015 - Cash Flow Hedges [Member] - Designated as Hedging Instrument [Member] - Interest Rate Caps [Member] € in Thousands, £ in Thousands, CAD in Thousands, $ in Thousands	USD ($)DerivativeInstrument	GBP (£)DerivativeInstrument	CADDerivativeInstrument	EUR (€)DerivativeInstrument
USD [Member] | USD LIBOR [Member]
Derivative [Line Items]
Number of Instruments	26	26	26	26
Notional Amount | $	$ 1,097,632
Strike	2.00%	2.00%	2.00%	2.00%
Wtd. Avg. Maturity (Years)	1 year 3 months 18 days
CAD [Member] | CDOR [Member]
Derivative [Line Items]
Number of Instruments	7	7	7	7
Notional Amount | CAD			CAD 483,286
Strike	2.00%	2.00%	2.00%	2.00%
Wtd. Avg. Maturity (Years)	1 year 2 months 12 days
EUR [Member] | EURIBOR [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | €				€ 152,710
Strike	2.00%	2.00%	2.00%	2.00%
Wtd. Avg. Maturity (Years)	1 year
GBP [Member] | GBP LIBOR [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | £		£ 15,142
Strike	2.00%	2.00%	2.00%	2.00%
Wtd. Avg. Maturity (Years)	1 year 3 months 18 days

Derivative Financial Instrume62

Derivative Financial Instruments - Summary of Outstanding Non-designated Hedges (Detail) - Not Designated as Hedging Instrument [Member] € in Thousands, £ in Thousands, CAD in Thousands, $ in Thousands	Dec. 31, 2015USD ($)DerivativeInstrument	Dec. 31, 2015GBP (£)DerivativeInstrument	Dec. 31, 2015CADDerivativeInstrument	Dec. 31, 2015EUR (€)DerivativeInstrument
Foreign Exchange Forward [Member] | CAD [Member] | Buy CAD / Sell USD Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | CAD			CAD 1,000
Foreign Exchange Forward [Member] | CAD [Member] | Buy USD / Sell CAD Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | CAD			CAD 1,000
Foreign Exchange Forward [Member] | GBP [Member] | Buy GBP / Sell USD Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | £		£ 10,400
Foreign Exchange Forward [Member] | GBP [Member] | Buy USD / Sell GBP Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | £		£ 10,400
Foreign Exchange Forward [Member] | EUR [Member] | Buy GBP / Sell EUR Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | €				€ 12,857
Interest Rate Caps [Member] | CAD [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	4	4	4	4
Notional Amount | CAD			CAD 67,303
Interest Rate Caps [Member] | USD [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | $	$ 13,387

Derivative Financial Instrume63

Derivative Financial Instruments - Summary of Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	$ 8,657	$ 1,138
Fair Value of Derivatives in a Liability Position	1,448
Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	8,237	1,138
Fair Value of Derivatives in a Liability Position	511
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	7,999	$ 1,138
Fair Value of Derivatives in a Liability Position	511
Designated as Hedging Instrument [Member] | Interest Rate Caps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	238
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	420
Fair Value of Derivatives in a Liability Position	937
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	419
Fair Value of Derivatives in a Liability Position	937
Not Designated as Hedging Instrument [Member] | Interest Rate Caps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	$ 1

Derivative Financial Instrume64

Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)	$ 23,882	$ 1,138
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(4)
Net Investment Hedges [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 (Effective Portion)	25,356	$ 1,138
Cash Flow Hedges [Member] | Interest Rate Caps [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)	(1,474)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (4)

Derivative Financial Instrume65

Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)Contract
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on termination of residual interest rate swaps			$ 136,000
Number of interest rate swap agreements terminated | Contract			5
Net Investment Hedges [Member] | Foreign Currency Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net cash settlements on our foreign currency forward contracts	$ 18,800,000	$ 0	$ 0
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate swaps, termination period			2013-06

Equity - Additional Information

Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jan. 15, 2016	Dec. 14, 2015	May. 09, 2014	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 25, 2014
Class of Stock [Line Items]
Total stock, shares authorized												300,000,000
Preferred stock, shares authorized												100,000,000
Preferred stock issued												0
Preferred stock outstanding												0
Plan adoption date												Mar. 25, 2014
Net proceeds from issuance of common stock												$ 1,029,540	$ 766,138	$ 633,807
Dividends declared per share of common stock		$ 0.62										$ 2.28	$ 1.98	$ 0.72
Date of dividend paid												Jan. 15, 2016
Date of dividend declared												Dec. 14, 2015
Record date of dividend paid												Dec. 31, 2015
Accumulated other comprehensive loss							$ 15,024					$ 32,758	$ 15,024
Gain related to changes in fair value of derivative instruments												25,000
Cumulative currency translation adjustment on assets and liabilities denominated in foreign currencies												57,800
CT Legacy Partners' total equity							60,800					22,500	60,800
Equity interests owned by Blackstone Mortgage Trust, Inc.							25,300					9,400	25,300
Non-controlling interests in CT Legacy Partners							$ 35,500					$ 13,100	$ 35,500
Subsequent Events [Member]
Class of Stock [Line Items]
Dividends paid	$ 58,100
Dividends paid per common stock	$ 0.62
Class A Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized							200,000,000					200,000,000	200,000,000
Common stock, shares issued under dividend reinvestment component												597	6
Number of shares sold during period				11,500,000	280,025	23,000,000	100,000	9,200,000	9,200,000	9,775,000	25,875,000	34,780,025	28,275,000
Net proceeds from issuance of common stock				$ 337,918	$ 7,895	$ 683,722	$ 2,758	$ 252,530	$ 254,758	$ 256,092		$ 1,029,535	$ 766,138
Class A Common Stock [Member] | ATM Agreements [Member]
Class of Stock [Line Items]
Aggregate sales price			$ 200,000
Number of shares sold during period												280,025	100,000
Net proceeds from issuance of common stock												$ 7,900	$ 2,800
Aggregate sales price remaining available												$ 188,600
Dividend Reinvestment and Direct Stock Purchase Plan [Member] | Class A Common Stock [Member]
Class of Stock [Line Items]
Reserved for issuance of class A common stock												9,999,397			10,000,000

Equity - Summary of Class A Com

Equity - Summary of Class A Common Stock Issuances (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended								12 Months Ended
	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Net proceeds									$ 1,029,540	$ 766,138	$ 633,807
Class A Common Stock [Member]
Class of Stock [Line Items]
Shares issued	11,500,000	280,025	23,000,000	100,000	9,200,000	9,200,000	9,775,000	25,875,000	34,780,025	28,275,000
Share issue price	$ 29.42	$ 29.97	$ 29.75	$ 27.58	$ 27.49	$ 27.72	$ 26.25		$ 29.64	$ 27.14
Net proceeds	$ 337,918	$ 7,895	$ 683,722	$ 2,758	$ 252,530	$ 254,758	$ 256,092		$ 1,029,535	$ 766,138

Equity - Summary of Class A C68

Equity - Summary of Class A Common Stock Issuances (Parenthetical) (Detail) - shares	1 Months Ended								12 Months Ended
	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Class A Common Stock [Member]
Class of Stock [Line Items]
Shares issued	11,500,000	280,025	23,000,000	100,000	9,200,000	9,200,000	9,775,000	25,875,000	34,780,025	28,275,000

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) - Class A Common Stock [Member] - shares	1 Months Ended								12 Months Ended
	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Beginning balance							29,602,884		58,388,808	29,602,884
Issuance of class A common stock	11,500,000	280,025	23,000,000	100,000	9,200,000	9,200,000	9,775,000	25,875,000	34,780,025	28,275,000
Issuance of restricted class A common stock, net									651,815	490,381
Issuance of deferred stock units									22,602	20,537
Ending balance				58,388,808					93,843,847	58,388,808

Equity - Schedule of Movement70

Equity - Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units (Parenthetical) (Detail) - shares	Dec. 31, 2015	Dec. 31, 2014
Class A Common Stock [Member]
Deferred stock units held by directors	141,521	118,919

Equity - Schedule of Dividend A

Equity - Schedule of Dividend Activity (Detail) - $ / shares	Dec. 14, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Dividends declared per share of common stock	$ 0.62	$ 2.28	$ 1.98	$ 0.72
Percent taxable as ordinary dividends		92.36%	99.52%	100.00%
Percent taxable as capital gain dividends		7.64%	0.48%	0.00%
Percentage of taxable dividend		100.00%	100.00%	100.00%

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								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 65,264	$ 66,888	$ 29,284	$ 35,393	$ 21,490	$ 22,024	$ 33,466	$ 13,065	$ 196,829	$ 90,045	$ 15,032
Weighted-average shares outstanding, basic and diluted									81,740,227	48,394,478	18,520,052
Per share amount, basic and diluted	$ 0.70	$ 0.72	$ 0.36	$ 0.60	$ 0.37	$ 0.45	$ 0.70	$ 0.34	$ 2.41	$ 1.86	$ 0.81

Other Expenses - Additional Inf

Other Expenses - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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 (or the period since the date of the first offering of our class A common stock following December 19, 2012, whichever is shorter) 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	$ 42,886,000	$ 19,491,000	$ 5,937,000
Manager [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fees	32,200,000	17,800,000	5,900,000
Incentive fees payable	10,700,000	1,700,000	$ 0
Accrued management fees payable	14,400,000	6,300,000
Accrued incentive fees payable	$ 14,400,000	6,300,000
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%
Percentage of pool vested	50.00%
Vested pool, percentage	75.00%
Fully vested pool, percentage	27.00%
Percentage of pool vesting upon receipt of dividends	23.00%
Description of incentive management fee awards to employees vesting schedule	Approximately 50% of the pool is 75% vested as of December 31, 2015, with the remainder contingent on continued employment with an affiliate of our Manager and our receipt of distributions from CT Legacy Partners. Of the remaining 50% of the pool, 27% is fully vested as a result of an acceleration event, and 23% vest only upon our receipt of distributions from CT Legacy Partners.
Accrued payables, awards	$ 1,300,000	$ 2,800,000

Other Expenses - Schedule of Ge

Other Expenses - Schedule of General and Administrative Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Professional services	$ 3,156	$ 2,324	$ 1,889
Operating and other costs	2,709	1,980	1,762
Subtotal	15,488	4,304	3,651
Non-cash and CT Legacy Portfolio compensation expenses
Restricted class A common stock earned	12,966	7,988	1,064
Subtotal	20,888	22,635	6,416
General and administrative expenses	36,709	27,799	11,505
General and Administrative Expense [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Director stock-based compensation	375	375	263
CT Legacy Partners [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Management incentive awards plan	2,177	1,374	5,089
Blackstone [Member]
Non-cash and CT Legacy Portfolio compensation expenses
General and administrative expenses	36,376	26,939	10,067
REIT [Member]
Non-cash and CT Legacy Portfolio compensation expenses
General and administrative expenses	333	860	$ 1,438
General Electrical Capital Corporation [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
GE transaction costs	9,623
CT Opportunity Partners I, LP [Member]
Non-cash and CT Legacy Portfolio compensation expenses
Management incentive awards plan	$ 5,370	$ 12,898

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended								12 Months Ended
	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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 provision									$ 504,000	$ 518,000	$ 995,000
Deferred tax assets				$ 0					0	0
Deferred tax liabilities				$ 0					0	$ 0
Net operating losses carried forward									159,000,000
Net capital losses carried forward									$ 602,000
NOLs expiration date									Dec. 31, 2029
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses and net capital losses									$ 2,000,000
Class A Common Stock [Member]
Tax Credit Carryforward [Line Items]
Common stock, shares issued	11,500,000	280,025	23,000,000	100,000	9,200,000	9,200,000	9,775,000	25,875,000	34,780,025	28,275,000
Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year									2,012
Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year									2,015

Stock-Based Incentive Plans - A

Stock-Based Incentive Plans - Additional Information (Detail) $ in Millions	Dec. 31, 2015USD ($)Plansshares	Dec. 31, 2015USD ($)Plansshares	Dec. 31, 2014shares	Dec. 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of benefit plans | Plans	5	5
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	1,114,908	1,114,908	919,719	700,000
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 2 months 12 days
Vest in 2016 [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	567,705	567,705
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	383,866	383,866
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	163,337	163,337
Stock Incentive Current Plan [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan	264,902	264,902
Maximum number of shares available under plan	2,160,106	2,160,106
Expired Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan	0	0

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] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Class A Common Stock, Beginning Balance	919,719	700,000
Restricted Class A Common Stock, Granted	679,958	490,381
Restricted Class A Common Stock, Vested	(456,626)	(270,662)
Restricted Class A Common Stock, Forfeited	(28,143)
Restricted Class A Common Stock, Ending Balance	1,114,908	919,719
Weighted-Average Grant Date Fair Value Per Share, Beginning Balance	$ 26.86	$ 25.69
Weighted-Average Grant Date Fair Value Per Share, Granted	28.25	27.82
Weighted-Average Grant Date Fair Value Per Share, Vested	26.94	25.57
Weighted-Average Grant Date Fair Value Per Share, Forfeited	28.28
Weighted-Average Grant Date Fair Value Per Share, Ending Balance	$ 27.64	$ 26.86

Fair Values - Assets and Liabil

Fair Values - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Derivatives	$ 8,657	$ 1,138
Other assets, at fair value	14,220	49,017
Liabilities
Derivatives	1,448
Level 2 [Member]
Assets
Derivatives	8,657	1,138
Other assets, at fair value	1,659	1,510
Liabilities
Derivatives	1,448
Level 3 [Member]
Assets
Other assets, at fair value	$ 12,561	$ 47,507

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] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning	$ 47,507	$ 54,461
Proceeds from investment realizations	(57,039)	(20,231)
Adjustments to fair value included in earnings
Gain on investments at fair value	22,093	13,277
Balance, ending	$ 12,561	$ 47,507

Fair Values - Additional Inform

Fair Values - Additional Information (Detail) - Recurring [Member] - Level 3 [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 12,561	$ 47,507	$ 54,461
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 12,600

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	Dec. 31, 2015	Dec. 31, 2014
Financial liabilities
Loan participations sold	$ 497,032	$ 496,080
Carrying Amount [Member]
Financial assets
Cash and cash equivalents	96,450	51,810
Restricted cash	9,556	11,591
Loans receivable, net	9,077,007	4,428,500
Financial liabilities
Secured debt agreements	6,116,105	2,353,279
Loan participations sold	497,032	496,080
Convertible notes, net	164,026	161,455
Face Amount [Member]
Financial assets
Cash and cash equivalents	96,450	51,810
Restricted cash	9,556	11,591
Loans receivable, net	9,108,361	4,462,897
Financial liabilities
Secured debt agreements	6,131,751	2,365,336
Loan participations sold	498,992	499,433
Convertible notes, net	172,500	172,500
Fair Value [Member]
Financial assets
Cash and cash equivalents	96,450	51,810
Restricted cash	9,556	11,591
Loans receivable, net	9,121,732	4,462,897
Financial liabilities
Secured debt agreements	6,131,751	2,365,336
Loan participations sold	498,992	499,433
Convertible notes, net	$ 171,344	$ 181,341

Transactions with Related Par82

Transactions with Related Parties - Additional Information (Detail) - USD ($)	Dec. 31, 2015	May. 08, 2015	Oct. 23, 2013	Oct. 02, 2013	May. 13, 2013	Aug. 31, 2015	May. 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 09, 2016	Jun. 30, 2015	Apr. 10, 2015	Jun. 20, 2014	Nov. 19, 2013	May. 30, 2013	May. 22, 2013
Related Party Transaction [Line Items]
Joint venture agreement date												May 13, 2013
Joint venture agreement end date												May 30, 2013
Percentage of equity interest purchased					100.00%															100.00%
Charge to non-controlling interest from purchase of equity interests at fair value					$ 193,000
Convertible notes	$ 164,026,000									$ 164,026,000	$ 161,455,000	$ 164,026,000	$ 161,455,000
Amount of loan originated									$ 320,000,000			33,501,000	35,449,000	$ 25,402,000
Purchased loan from third party			$ 176,900,000
Loss on deconsolidation													8,615,000
CT CDO I [Member]
Related Party Transaction [Line Items]
Principal balance of loans																		$ 27,000,000
Carrying value of loans																		27,000,000
Loss on deconsolidation											$ 8,600,000
Net proceeds to investments from collateral property										0
CT Legacy Partners [Member]
Related Party Transaction [Line Items]
Principal balance of loans																		8,000,000
Carrying value of loans																		$ 0
Net proceeds to investments from collateral property										$ 0
Aggregate incentive compensation payments												$ 2,177,000	$ 1,374,000	5,089,000
General Electrical Capital Corporation [Member]
Related Party Transaction [Line Items]
Purchase price of Loan Portfolio																$ 4,700,000,000
General Electrical Capital Corporation [Member] | Loan Purchase Commitments [Member] | Commercial Portfolio Segment [Member]
Related Party Transaction [Line Items]
Portfolio of loans acquired																	$ 4,600,000,000
Purchase price of Loan Portfolio																	$ 23,000,000,000
Restricted Class A Common Stock [Member]
Related Party Transaction [Line Items]
Restricted shares, vesting period												3 years
Class A Common Stock [Member]
Related Party Transaction [Line Items]
Common stock, shares issued	93,702,326									93,702,326	58,269,889	93,702,326	58,269,889
Common stock, par value	$ 0.01									$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock value	$ 937,000									$ 937,000	$ 583,000	$ 937,000	$ 583,000
Manager [Member]
Related Party Transaction [Line Items]
Management Agreement expiration date												Dec. 19, 2016
Management Agreement renewal term, description												The initial term of which expires on December 19, 2016 and will be automatically renewed for a one-year term each anniversary thereafter unless earlier terminated.
Management Agreement renewal term, period												1 year
Aggregate incentive compensation payments												$ 10,700,000	1,700,000	0
Accrued management and incentive fees payable	14,400,000									14,400,000	6,300,000	14,400,000	6,300,000
Management fees paid to Manager												34,800,000	15,700,000	3,400,000
Expenses reimbursed to Manager												311,000	115,000	0
Manager [Member] | CT Legacy Partners [Member]
Related Party Transaction [Line Items]
Recognized gain on investments												21,600,000
Net sale proceeds assumed												40,100,000
Expected net sales proceeds, amount received	37,700,000
Manager [Member] | Incentive Awards Plan [Member] | CT Legacy Partners [Member]
Related Party Transaction [Line Items]
Aggregate incentive compensation payments		$ 2,700,000
Incentive compensation amount paid		$ 2,500,000
Manager [Member] | Class A Common Stock [Member] | April 2015 Stock Offering [Member]
Related Party Transaction [Line Items]
Common stock, shares issued								1,885,245
Public offing price per share								$ 30.50
Manager [Member] | Class A Common Stock [Member] | Restricted Class A Common Stock [Member]
Related Party Transaction [Line Items]
Common stock value	9,300,000									9,300,000	9,400,000	$ 9,300,000	$ 9,400,000	$ 8,500,000
Issuance of restricted class A common stock												334,758	337,941	339,431
Non-cash expense												$ 6,700,000	$ 3,800,000	$ 767,000
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
Blackstone [Member]
Related Party Transaction [Line Items]
Percentage of equity interest purchased in joint venture					16.70%
Affiliates of Manager [Member]
Related Party Transaction [Line Items]
Percentage of equity interest purchased in joint venture					83.30%
Convertible notes																			$ 188,000
Amount of loan originated				$ 71,000,000			$ 590,000,000
Modification fee			$ 2,300,000
Affiliates of Manager [Member] | Third-Party Service Provider [Member]
Related Party Transaction [Line Items]
Administrative services expenses incurred												$ 372,000	202,000	9,000
Affiliates of Manager [Member] | Class A Common Stock [Member]
Related Party Transaction [Line Items]
Common stock, shares issued																					1,960,784
Common stock, par value																					$ 25.50
Common stock value																					$ 1,000,000
Affiliates of Manager [Member] | Class A Common Stock [Member] | Subsequent Events [Member]
Related Party Transaction [Line Items]
Common stock, shares outstanding percentage															4.70%
Affiliates of Manager [Member] | Class A Common Stock [Member] | April 2015 Stock Offering [Member]
Related Party Transaction [Line Items]
Compensation made to co-manager for stock offering								$ 761,000
Affiliate of our Manager [Member]
Related Party Transaction [Line Items]
Special servicing fees payable											522,000		522,000	847,000
Special servicing fees													139,000	847,000
Accrued special servicing fee payable	1,100,000									1,100,000		1,100,000
Affiliate of our Manager [Member] | CT CDO I [Member]
Related Party Transaction [Line Items]
Special servicing fees payable	0									0	522,000	0	522,000	847,000
Independent Members of Board of Directors [Member] | General Electrical Capital Corporation [Member] | Loan Purchase Commitments [Member] | Commercial Portfolio Segment [Member]
Related Party Transaction [Line Items]
Payments for special committee services						$ 53,000
BXMT Advisors Limited Liability Company and Affiliates [Member]
Related Party Transaction [Line Items]
Modification fee									$ 354,000
Preferred distributions payable to affiliate of our Manager	$ 83,333									$ 83,333	$ 151,000	83,333	151,000
Payments of preferred distributions to affiliate of our Manager												$ 1,300,000	$ 2,100,000	$ 3,900,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Dec. 31, 2015USD ($)LoansDirectors	Dec. 31, 2015USD ($)LoansInstallments	Dec. 31, 2014USD ($)
Commitments And Contingencies [Line Items]
Commitments expiration period		4 years	4 years
Number of loans receivable | Loans	69	69
Percentage of compensation paid in cash	40.00%
Percentage of compensation in the form of deferred stock units	60.00%
Number of board of directors | Directors	8
Number of independent directors entitled to annual compensation | Directors	5
Number of equal quarterly installments | Installments		4
CT Investment Management Co LLC [Member] | Internal Revenue Service [Member]
Commitments And Contingencies [Line Items]
Income tax examinations, reserves	$ 0	$ 0
CT Investment Management Co LLC [Member] | New York State Division of Taxation and Finance [Member]
Commitments And Contingencies [Line Items]
Income tax examinations, reserves	0	0
Loans Receivable [Member]
Commitments And Contingencies [Line Items]
Unfunded loan commitments	700,658,000	$ 700,658,000	$ 513,229,000
Five Independent Board of Directors [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	125,000
Three Board of Directors [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	0
Chairperson of Audit Committee [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	$ 12,000

Summary of Quarterly Results 84

Summary of Quarterly Results of Operations - Summary of Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Income from loans and other investments, net	$ 82,094	$ 87,032	$ 49,847	$ 39,246	$ 36,812	$ 30,483	$ 26,746	$ 21,582	$ 258,219	$ 115,623	$ 35,147
Net income	65,597	67,778	32,417	46,093	25,338	23,601	38,439	13,116	211,885	100,494	25,424
Net income attributable to Blackstone Mortgage Trust, Inc.	$ 65,264	$ 66,888	$ 29,284	$ 35,393	$ 21,490	$ 22,024	$ 33,466	$ 13,065	$ 196,829	$ 90,045	$ 15,032
Net income per share of class A common stock:
Basic and diluted	$ 0.70	$ 0.72	$ 0.36	$ 0.60	$ 0.37	$ 0.45	$ 0.70	$ 0.34	$ 2.41	$ 1.86	$ 0.81

Schedule IV - Mortgage Loans 85

Schedule IV - Mortgage Loans on Real Estate (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 1,039,765
Face Amount of Loans	9,108,361
Carrying Amount of Loans	9,077,007
Subordinate Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Prior Liens	1,039,765
Face Amount of Loans	232,845
Carrying Amount of Loans	$ 229,962
Subordinate Loans [Member] | Various / Diversified [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Various / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates	12.22%
Periodic Payment Terms	I/O
Prior Liens	$ 1,039,765
Face Amount of Loans	232,845
Carrying Amount of Loans	$ 229,962
Senior Mortgage Loans in Excess of 3% of the Carrying Amount of Total Loans [Member] | MHC [Member] | Borrower A [Member]
Mortgage Loans on Real Estate [Line Items]
Location	MHC / Diversified-US
Fixed Interest Payment Rates	4.89%
Maximum Maturity Date	2,019
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 338,565
Carrying Amount of Loans	$ 339,613
Senior Mortgage Loans in Excess of 3% of the Carrying Amount of Total Loans [Member] | MHC [Member] | Borrower B [Member]
Mortgage Loans on Real Estate [Line Items]
Location	MHC / Diversified-US
Fixed Interest Payment Rates	5.29%
Maximum Maturity Date	2,016
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 304,710
Carrying Amount of Loans	$ 306,152
Senior Mortgage Loans in Excess of 3% of the Carrying Amount of Total Loans [Member] | Hotel [Member] | Borrower C [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Hotel / U.K.
Debt instrument variable rate basis	LIBOR
Interest Payment Rates	4.00%
Maximum Maturity Date	2,019
Periodic Payment Terms	I/O
Face Amount of Loans	$ 296,320
Carrying Amount of Loans	$ 293,192
Senior Mortgage Loans in Excess of 3% of the Carrying Amount of Total Loans [Member] | Office [Member] | Borrower D [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Office / Northeast
Debt instrument variable rate basis	LIBOR
Interest Payment Rates	3.45%
Maximum Maturity Date	2,020
Periodic Payment Terms	I/O
Face Amount of Loans	$ 294,500
Carrying Amount of Loans	$ 292,061
Senior Mortgage Loans in Excess of 3% of the Carrying Amount of Total Loans [Member] | Office [Member] | Borrower E [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Office / Northeast
Debt instrument variable rate basis	LIBOR
Interest Payment Rates	3.50%
Maximum Maturity Date	2,020
Periodic Payment Terms	I/O
Face Amount of Loans	$ 274,878
Carrying Amount of Loans	272,632
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Face Amount of Loans	7,366,543
Carrying Amount of Loans	$ 7,343,395
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | MHC [Member]
Mortgage Loans on Real Estate [Line Items]
Location	MHC / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates, Minimum	4.67%
Fixed Interest Payment Rates, Maximum	6.30%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 715,857
Carrying Amount of Loans	$ 715,806
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Hotel [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Hotel / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates, Minimum	5.30%
Fixed Interest Payment Rates, Maximum	6.08%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 1,603,592
Carrying Amount of Loans	$ 1,600,332
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Office [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Office / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates, Minimum	4.46%
Fixed Interest Payment Rates, Maximum	6.48%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 3,567,658
Carrying Amount of Loans	$ 3,550,802
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Retail [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Retail / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates, Minimum	5.14%
Fixed Interest Payment Rates, Maximum	5.38%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 610,163
Carrying Amount of Loans	$ 608,275
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Multifamily [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Multifamily / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates, Minimum	4.28%
Fixed Interest Payment Rates, Maximum	6.03%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 542,376
Carrying Amount of Loans	$ 540,184
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Condo / Northeast [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Condo / Northeast
Debt instrument variable rate basis	LIBOR
Interest Payment Rates	3.75%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 84,096
Carrying Amount of Loans	$ 83,920
Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Other [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Other / Diversified
Debt instrument variable rate basis	LIBOR
Fixed Interest Payment Rates, Minimum	4.63%
Fixed Interest Payment Rates, Maximum	6.22%
Periodic Payment Terms	I/O & P/I
Face Amount of Loans	$ 242,801
Carrying Amount of Loans	244,076
Senior Mortgage Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Face Amount of Loans	8,875,516
Carrying Amount of Loans	$ 8,847,045
Minimum [Member] | Subordinate Loans [Member] | Various / Diversified [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	10.75%
Maximum Maturity Date	2,019
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | MHC [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	1.75%
Maximum Maturity Date	2,016
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Hotel [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.25%
Maximum Maturity Date	2,016
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Office [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	2.30%
Maximum Maturity Date	2,016
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Retail [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.10%
Maximum Maturity Date	2,017
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Multifamily [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.40%
Maximum Maturity Date	2,017
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Condo / Northeast [Member]
Mortgage Loans on Real Estate [Line Items]
Maximum Maturity Date	2,017
Minimum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Other [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.30%
Maximum Maturity Date	2,016
Maximum [Member] | Subordinate Loans [Member] | Various / Diversified [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	12.83%
Maximum Maturity Date	2,022
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | MHC [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	5.00%
Maximum Maturity Date	2,021
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Hotel [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.50%
Maximum Maturity Date	2,021
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Office [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	5.50%
Maximum Maturity Date	2,020
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Retail [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.50%
Maximum Maturity Date	2,019
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Multifamily [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.50%
Maximum Maturity Date	2,025
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Condo / Northeast [Member]
Mortgage Loans on Real Estate [Line Items]
Maximum Maturity Date	2,019
Maximum [Member] | Senior Mortgage Loans Less Than 3% of the Carrying Amount of Total Loans [Member] | Other [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	5.00%
Maximum Maturity Date	2,019

Schedule IV - Mortgage Loans 86

Schedule IV - Mortgage Loans on Real Estate (Parenthetical) (Detail) $ in Billions	Dec. 31, 2015USD ($)
Mortgage Loans on Real Estate [Abstract]
Tax basis of mortgage loans	$ 8.6

Schedule IV - Reconciliation of

Schedule IV - Reconciliation of Mortgage Loans on Real Estate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Mortgage Loans on Real Estate [Abstract]
Balance at January 1,	$ 4,428,500	$ 2,047,223	$ 141,500
Additions during period:
Loan fundings	7,203,145	3,067,263	2,327,914
Amortization of deferred fees and expenses	36,052	19,785	5,965
Unrealized gain on foreign currency translation			796
Valuation allowance on loans held-for-sale			1,259
Deductions during period:
Collections of principal	(2,407,920)	(564,183)	(383,647)
Unrealized loss on foreign currency translation	(149,269)	(52,076)
Deferred origination fees and expenses	(33,501)	(35,449)	(25,402)
Loans sold		(27,063)	(21,162)
Transfers to other assets		(27,000)
Balance at December 31,	$ 9,077,007	$ 4,428,500	$ 2,047,223