Reckson Operating Partnership 10-Q 12 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	May 11, 2017
Document and Entity Information
Entity Registrant Name	RECKSON OPERATING PARTNERSHIP LP
Entity Central Index Key	930,810
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		0
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Commercial real estate properties, at cost:
Land and land interests	$ 1,790,388	$ 1,805,198
Building and improvements	4,577,417	4,629,994
Building leasehold and improvements	1,073,703	1,073,678
Commercial real estate properties, gross	7,441,508	7,508,870
Less: accumulated depreciation	(1,512,514)	(1,437,222)
Total commercial real estate properties, net	5,928,994	6,071,648
Assets held for sale	54,694	0
Cash and cash equivalents	61,410	59,930
Restricted cash	44,304	43,489
Tenant and other receivables, net of allowance of $5,113 and $4,879 in 2017 and 2016, respectively	28,907	30,999
Deferred rents receivable, net of allowance of $16,688 and $17,798 in 2017 and 2016, respectively	242,114	238,447
Debt and preferred equity investments, net of discounts and deferred origination fees of $16,316 and $16,705 in 2017 and 2016, respectively	1,627,836	1,640,412
Investments in unconsolidated joint ventures	174,678	174,127
Deferred costs, net of accumulated amortization of $74,815 and $73,673 in 2017 and 2016, respectively	118,365	121,470
Other assets	343,468	374,091
Total assets	8,624,770	8,754,613
Liabilities
Mortgages and other loans payable, net	920,602	676,068
Unsecured term loan, net	1,179,861	1,179,521
Unsecured notes, net	795,602	795,260
Accrued interest payable	12,158	15,781
Other liabilities	119,086	160,982
Accounts payable and accrued expenses	61,354	60,855
Related party payables	23,808	23,808
Deferred revenue	159,899	161,772
Deferred land leases payable	1,818	1,795
Dividends payable	807	754
Security deposits	40,176	40,033
Liabilities related to assets held for sale	43	0
Total liabilities	3,315,214	3,116,629
Commitments and contingencies	0	0
Preferred units	109,161	109,161
Capital
General partner capital	4,811,515	5,139,842
Accumulated other comprehensive loss	(1,528)	(1,618)
Total ROP partner's capital	4,809,987	5,138,224
Noncontrolling interests in other partnerships	390,408	390,599
Total capital	5,200,395	5,528,823
Total liabilities and capital	$ 8,624,770	$ 8,754,613

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Tenant and other receivables, allowance	$ 5,113	$ 4,879
Deferred rents receivable, allowance	16,688	17,798
Preferred equity investments, deferred origination fees and discounts	16,316	16,705
Deferred costs, accumulated amortization	$ 74,815	$ 73,673

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues
Rental revenue, net	$ 167,972	$ 159,618
Escalation and reimbursement	24,545	24,316
Investment income	40,554	55,180
Other (loss) income	(716)	550
Total revenues	232,355	239,664
Expenses
Operating expenses, including related party expenses of $6,529 and $5,763 in 2017 and 2016	41,725	41,961
Real estate taxes	38,796	37,224
Ground rent	5,235	5,235
Interest expense, net of interest income	29,467	32,201
Amortization of deferred financing costs	2,087	2,140
Depreciation and amortization	51,784	50,798
Transaction related costs	0	178
Marketing, general and administrative	112	184
Total expenses	169,206	169,921
Income before equity in net income from unconsolidated joint ventures, equity in net gain on sale of interest in unconsolidated joint venture/real estate, and depreciable real estate reserves	63,149	69,743
Equity in net income from unconsolidated joint ventures	4,255	2,457
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	3	0
Depreciable real estate reserves	(56,265)	0
Net income	11,142	72,200
Net income attributable to noncontrolling interests in other partnerships	(14)	(12)
Preferred units dividend	(953)	(955)
Net income attributable to ROP common unitholder	$ 10,175	$ 71,233

Consolidated Statements of Ope5

Consolidated Statements of Operations (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Related party expenses included in operating expenses	$ 6,529	$ 5,763

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income attributable to ROP common unitholder	$ 10,175	$ 71,233
Other comprehensive income:
Change in net unrealized gain on derivative instruments	90	220
Comprehensive income attributable to ROP common unitholder	$ 10,265	$ 71,453

Consolidated Statement of Capit

Consolidated Statement of Capital (Unaudited) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
Increase (Decrease) in Partners' Capital
Beginning Balance	$ 5,528,823
Contributions	629,146
Distributions	(967,853)
Net income	10,189
Other comprehensive income	90
Ending Balance	5,200,395
General Partner's Capital Class A Common Units | Class A Common Units
Increase (Decrease) in Partners' Capital
Beginning Balance	5,139,842
Contributions	629,146
Distributions	(967,648)
Net income	10,175
Ending Balance	4,811,515
Limited Partner's Capital
Increase (Decrease) in Partners' Capital
Beginning Balance	0
Ending Balance	0
Noncontrolling Interests In Other Partnerships
Increase (Decrease) in Partners' Capital
Beginning Balance	390,599
Distributions	(205)
Net income	14
Ending Balance	390,408
Accumulated Other Comprehensive (Loss) Income
Increase (Decrease) in Partners' Capital
Beginning Balance	(1,618)
Other comprehensive income	90
Ending Balance	$ (1,528)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Activities
Net income	$ 11,142	$ 72,200
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	53,871	52,938
Equity in net income from unconsolidated joint venture	(4,255)	(2,457)
Distributions of cumulative earnings from unconsolidated joint ventures	3,606	2,128
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(3)	0
Depreciable real estate reserve	56,265	0
Deferred rents receivable	(3,835)	(6,070)
Other non-cash adjustments	(7,959)	(8,714)
Changes in operating assets and liabilities:
Restricted cash—operations	(815)	(2,022)
Tenant and other receivables	961	4,616
Deferred lease costs	(2,769)	(6,743)
Other assets	(42,414)	(37,394)
Accounts payable, accrued expenses and other liabilities	269	(6,626)
Deferred revenue and land leases payable	4,408	3,181
Net cash provided by operating activities	68,472	65,037
Investing Activities
Additions to land, buildings and improvements	(13,086)	(16,157)
Escrowed cash—capital improvements	0	368
Investments in unconsolidated joint venture	(7)	0
Distributions in excess of cumulative earnings from unconsolidated joint ventures	392	345
Net proceeds from disposition of real estate/joint venture interest	0	22,316
Other investments	32,057	7,922
Origination of debt and preferred equity investments	(402,453)	(117,119)
Repayments or redemption of preferred equity investments	411,969	272,253
Net cash provided by investing activities	28,872	169,928
Financing Activities
Proceeds from mortgages and other loans payable	250,000	0
Repayments of mortgages and other loans payable	0	(67,526)
Proceeds from credit facility and senior unsecured notes	277,800	520,000
Repayments of credit facility and senior unsecured notes	(277,800)	(994,308)
Distributions to noncontrolling interests in other partnerships	(205)	0
Contributions from common unitholder	625,842	1,750,905
Distributions to common and preferred unitholders	(968,601)	(1,507,017)
Other obligations related to loan participations	0	76,500
Deferred loan costs and capitalized lease obligation	(2,900)	(1,102)
Net cash used in financing activities	(95,864)	(222,548)
Net increase in cash and cash equivalents	1,480	12,417
Cash and cash equivalents at beginning of period	59,930	50,026
Cash and cash equivalents at end of period	61,410	62,443
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Tenant improvements and capital expenditures payable	3,503	8,745
Deferred leasing payable	103	79
Change in fair value of hedge	2	0
Transfer to assets held for sale	54,694	0
Transfer to liabilities related to assets held for sale	43	0
Contributions from a noncontrolling interest in other partnerships	0	68,581
Removal of fully depreciated commercial real estate properties	$ 643	$ 3,799

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation Reckson Operating Partnership, L.P., or ROP, commenced operations on June 2, 1995. The sole general partner of ROP is Wyoming Acquisition GP LLC., or WAGP, a wholly-owned subsidiary of SL Green Operating Partnership, L.P., or the Operating Partnership. The sole limited partner of ROP is the Operating Partnership. The Operating Partnership is 95.67% owned by SL Green Realty Corp., or SL Green, as of March 31, 2017 . SL Green is a self-administered and self-managed real estate investment trust, and is the sole managing general partner of the Operating Partnership. Unless the context requires otherwise, all references to "we," "our," "us" and the "Company" means ROP and all entities owned or controlled by ROP. ROP is engaged in the acquisition, ownership, management and operation of commercial and residential real estate properties, principally office properties, and also owns land for future development, located in New York City, Westchester County, Connecticut and New Jersey, which collectively is also known as the New York Metropolitan area. As of March 31, 2017 , we owned the following interests in properties in the New York Metropolitan area, primarily in midtown Manhattan. Our investments in the New York Metropolitan area also include investments in Brooklyn, Westchester County, Connecticut and New Jersey, which are collectively known as the Suburban properties: Location Type Number of Approximate Square Feet (unaudited) Weighted Average (1) (unaudited) Commercial: Manhattan Office 16 8,463,245 96.4 % Retail (2)(3)(4) 6 374,016 95.8 % Fee Interest 1 176,530 100.0 % 23 9,013,791 96.4 % Suburban Office (5) 18 3,251,000 83.0 % Retail 1 52,000 100.0 % 19 3,303,000 83.3 % Total commercial properties 42 12,316,791 92.9 % Residential: Manhattan Residential (2) — 222,855 94.0 % Total portfolio 42 12,539,646 92.9 % (1) The weighted average occupancy for commercial properties represents the total occupied square feet divided by total square footage at acquisition. The weighted average occupancy for residential properties represents the total occupied units divided by total available units. (2) As of March 31, 2017 , we owned a building that was comprised of approximately 270,132 square feet of retail space and approximately 222,855 square feet of residential space. For the purpose of this report, we have included the building in the number of retail properties we own. However, we have included only the retail square footage in the retail approximate square footage, and have listed the balance of the square footage as residential square footage. (3) Includes two unconsolidated joint venture retail properties at 131-137 Spring Street comprised of approximately 68,342 square feet. (4) Includes the property at 102 Greene Street, which is classified as held for sale at March 31, 2017. (5) Includes the property at 520 White Plains Road, which is classified as held for sale at March 31, 2017. As of March 31, 2017 , we held debt and preferred equity investments with a book value of $1.9 billion , including $0.3 billion of debt and preferred equity investments and other financing receivables that are included in other balance sheet line items. Basis of Quarterly Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for the fair presentation of the financial position of the Company at March 31, 2017 and the results of operations for the periods presented have been included. The operating results for the period presented are not necessarily indicative of the results that may be expected for the year ending December 31, 2017 . These financial statements should be read in conjunction with the financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2016 . The consolidated balance sheet at December 31, 2016 has been derived from the audited financial statements as of that date but do not include all the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Principles of Consolidation The consolidated financial statements include our accounts and those of our subsidiaries, which are wholly-owned or controlled by us. Entities which we do not control through our voting interest and entities which are variable interest entities, but where we are not the primary beneficiary, are accounted for under the equity method. See Note 5, "Debt and Preferred Equity Investments" and Note 6, "Investments in Unconsolidated Joint Ventures." All significant intercompany balances and transactions have been eliminated. We consolidate a variable interest entity, or VIE, in which we are considered the primary beneficiary. The primary beneficiary is the entity that has (i) the power to direct the activities that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. Included in commercial real estate properties on our consolidated balance sheets as of March 31, 2017 and December 31, 2016 are $1.4 billion and $1.4 billion , respectively, related to our consolidated VIEs. Included in mortgages and other loans payable on our consolidated balance sheets as of March 31, 2017 and December 31, 2016 are $494.3 million and $494.1 million, respectively, related to our consolidated VIEs. Investment in Commercial Real Estate Properties On a periodic basis, we assess whether there are any indications that the value of our real estate properties may be other than temporarily impaired or that their carrying value may not be recoverable. A property's value is considered impaired if management's estimate of the aggregate future cash flows (undiscounted) to be generated by the property is less than the carrying value of the property. To the extent impairment has occurred, the loss will be measured as the excess of the carrying amount of the property over the calculated fair value of the property. We also evaluate our real estate properties for potential impairment when a real estate property has been classified as held for sale. Real estate assets held for sale are valued at the lower of either their carrying value or fair value less costs to sell. We do not believe that there were any indicators of impairment at any of our consolidated properties at March 31, 2017 except for 520 White Plains Road in Tarrytown, New York, and 680/750 Washington Boulevard in Stamford, Connecticut, for which we recorded a $56.3 million depreciable real estate reserve during the three months ended March 31, 2017 . We allocate the purchase price of real estate to land and building (inclusive of tenant improvements) and, if determined to be material, intangibles, such as the value of above- and below-market leases and origination costs associated with the in-place leases. We depreciate the amount allocated to building (inclusive of tenant improvements) over their estimated useful lives, which generally range from three to 40 years . We amortize the amount allocated to the above- and below-market leases over the remaining term of the associated lease, which generally range from one to 14 years , and record it as either an increase (in the case of below-market leases) or a decrease (in the case of above-market leases) to rental income. We amortize the amount allocated to the values associated with in-place leases over the expected term of the associated lease, which generally ranges from one to 14 years . If a tenant vacates its space prior to the contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related intangible will be written off. The tenant improvements and origination costs are amortized as an expense over the remaining life of the lease (or charged against earnings if the lease is terminated prior to its contractual expiration date). We assess fair value of the leases based on estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends, and market/economic conditions that may affect the property. To the extent acquired leases contain fixed rate renewal options that are below-market and determined to be material, we amortize such below-market lease value into rental income over the renewal period. We recognized $4.2 million and $4.0 million of rental revenue for the three months ended March 31, 2017 and 2016 , respectively, for the amortization of aggregate below-market leases in excess of above-market leases and a reduction in lease origination costs, resulting from the allocation of the purchase price of the applicable properties. The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of March 31, 2017 and December 31, 2016 (in thousands): March 31, 2017 December 31, 2016 Identified intangible assets (included in other assets): Gross amount $ 309,678 $ 311,830 Accumulated amortization (254,821 ) (253,064 ) Net (1) $ 54,857 $ 58,766 Identified intangible liabilities (included in deferred revenue): Gross amount $ 521,873 $ 524,793 Accumulated amortization (372,100 ) (368,738 ) Net (1) $ 149,773 $ 156,055 (1) As of March 31, 2017 and December 31, 2016, $0.1 million and none , respectively and $0.1 million and none , respectively, of net intangible assets and net intangible liabilities, were reclassified to assets held for sale and liabilities related to assets held for sale. Fair Value Measurements See Note 12, "Fair Value Measurements." Investments in Unconsolidated Joint Ventures We assess our investments in unconsolidated joint ventures for recoverability, and if it is determined that a loss in value of the investment is other than temporary, we write down the investment to its fair value. We evaluate our equity investments for impairment based on the joint ventures' projected discounted cash flows. We do not believe that the values of any of our equity investments were impaired at March 31, 2017 . Reserve for Possible Credit Losses The expense for possible credit losses in connection with debt and preferred equity investments is the charge to earnings to increase the allowance for possible credit losses to the level that we estimate to be adequate, based on Level 3 data, considering delinquencies, loss experience and collateral quality. Other factors considered include geographic trends, product diversification, the size of the portfolio and current economic conditions. Based upon these factors, we establish a provision for possible credit loss on each individual investment. When it is probable that we will be unable to collect all amounts contractually due, the investment is considered impaired. Where impairment is indicated on an investment that is held to maturity, a valuation allowance is measured based upon the excess of the recorded investment amount over the net fair value of the collateral. Any deficiency between the carrying amount of an asset and the calculated value of the collateral is charged to expense. We continue to assess or adjust our estimates based on circumstances of a loan and the underlying collateral. If additional information reflects increased recovery of our investment, we will adjust our reserves accordingly. There were no loan reserves recorded during three months ended March 31, 2017 and 2016 . Income Taxes ROP is a disregarded entity of SL Green Operating Partnership, L.P. for federal income tax purposes, and, as a result, all income and losses of ROP are considered income and losses of SL Green Operating Partnership, L. P. No provision has been made for income taxes in the consolidated financial statements since such taxes, if any, are the responsibility of the individual partners of SL Green Operating Partnership, L.P. Shares Contributed by Parent Company We present shares of SL Green common stock as a contra-equity account in our financial statements. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash investments, debt and preferred equity investments and accounts receivable. We place our cash investments in excess of insured amounts with high quality financial institutions. The collateral securing our debt and preferred equity investments is located in New York City. See Note 5, "Debt and Preferred Equity Investments." We perform ongoing credit evaluations of our tenants and require most tenants to provide security deposits or letters of credit. Though these security deposits and letters of credit are insufficient to meet the total value of a tenant's lease obligation, they are a measure of good faith and a source of funds to offset the economic costs associated with lost revenue and the costs associated with re-tenanting a space. The properties in our real estate portfolio are primarily located in Manhattan. We also have properties located in Brooklyn, Westchester County, Connecticut and New Jersey. The tenants located in our buildings operate in various industries. No tenant in our portfolio accounted for more than 5.0% of our share of annualized cash rent, including our share of joint venture annualized rent, at March 31, 2017 . For the three months ended March 31, 2017 , 13.6% , 8.8% , 7.4% , 7.1% , 6.7% , 6.0% , 6.0% , and 6.0% of our share of cash rent, including our share of joint venture annualized rent was attributable to 1185 Avenue of the Americas, 625 Madison Avenue, 919 Third Avenue, 750 Third Avenue, 810 Seventh Avenue, 1350 Avenue of the Americas, 555 West 57th Street, and 125 Park Avenue, respectively. Our share of annualized cash rent for all other properties was below 5.0% Reclassification Certain prior year balances have been reclassified to conform to our current year presentation. Accounting Standards Updates In February 2017, the FASB issued guidance to clarify the scope of Subtopic 610-20 as well as provide guidance on accounting for partial sales of nonfinancial assets. Subtopic 610-20 was issued in May 2014 as part of ASU 2014-09. The Company anticipates adopting this guidance January 1, 2018, and applying the cumulative-effect adoption method. The Company is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In January, 2017, the FASB issued Accounting Standards Update (ASU) No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business The guidance clarifies the definition of a business and provides guidance to assist with determining whether transactions should be accounted for as acquisitions of assets or businesses. The main provision is that an acquiree is not a business if substantially all of the fair value of the gross assets is concentrated in a single identifiable asset or group of assets. The Company adopted the guidance on the issuance date effective January 5, 2017. The Company expects that most of our real estate acquisitions will be considered asset acquisitions under the new guidance and that transaction costs will be capitalized to the investment basis which is then subject to a purchase price allocation based on relative fair value. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The guidance will require entities to show the changes on the total cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities will not longer present transfers between these items on the statement of cash flows. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Company has not yet adopted this new guidance and is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The ASU provides final guidance on eight cash flow issues, including debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, distributions received from equity method investees, separately identifiable cash flows and application of the predominance principle, and others. The amendments in the ASU are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted the guidance effective January 1, 2017 and there was no impact on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The guidance changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The guidance replaces the current ‘incurred loss’ model with an ‘expected loss’ approach. The guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted after December 2018. The Company has not yet adopted this new guidance and is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The guidance simplifies the accounting for share-based payment award transactions including: income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The guidance is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Company adopted the guidance effective January 1, 2017 and there was no material impact on the Company’s consolidated financial statements. In March 2016, the FASB issued ASU 2016-07, Investments Equity Method and Joint Ventures (Topic 323). The guidance eliminates the requirement that an entity retroactively adopt the equity method of accounting if an investment qualifies for use of the equity method as a result of an increase in the level of ownership or degree of influence. The amendments require that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted the guidance effective January 1, 2017 and there was no impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases. The guidance requires lessees to recognize lease assets and lease liabilities for those leases classified as operating leases under the previous standard. Depending on the lease classification, lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. The accounting applied by a lessor is largely unchanged from that applied under the previous standard. One of the impacts on the Company will be the presentation and disclosure in the financial statements of non-lease components such as charges to tenants for a building’s operating expenses. The non-lease components will be presented separately from the lease components in both the Consolidated Statements of Operations and Consolidated Balance Sheets. Another impact is the measurement and presentation of ground leases under which the Company is lessee. The Company is required to record a liability for the obligation to make payments under the lease and an asset for the right to use the underlying asset during the lease term and will also apply the new expense recognition requirements given the lease classification. The Company is currently quantifying these impacts. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company anticipates adopting this guidance January 1, 2019 and will apply the modified retrospective approach. In January 2016, the FASB issued ASU 2016-01 (ASU 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and to record changes in instruments-specific credit risk for financial liabilities measured under the fair value option in other comprehensive income. The guidance is effective for fiscal years beginning after December 15, 2017, and for interim periods therein. The Company has not yet adopted this new guidance and is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In May 2014, the FASB issued a new comprehensive revenue recognition guidance which requires us to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods and services (ASU 2014-09). The guidance also requires enhanced disclosures to help users of financial statements better understand the nature, amount, timing, and uncertainty of revenue that is recognized. In March 2016, the FASB issued implementation guidance which clarifies principal versus agent considerations in reporting revenue gross versus net (ASU 2016-08). In April 2016, the FASB issued implementation guidance which clarifies the identification of performance obligations (ASU 2016-10). In April 2016, the FASB amended its new revenue recognition guidance on identifying performance obligations to allow entities to disregard items that are immaterial and clarify when a good or service is separately identifiable (ASU 2016-10). In May 2016, the FASB issued implementation guidance relating to transition, collectability, noncash consideration and presentation matters (ASU 2016-12). These ASUs are effective for annual and interim periods beginning after December 15, 2017. Early adoption is permitted but not before interim and annual reporting periods beginning after December 15, 2016. The new guidance can be applied either retrospectively to each prior reporting period presented, or as a cumulative-effect adjustment as of the date of adoption. The Company anticipates adopting this guidance January 1, 2018, and applying the cumulative-effect adoption method. Since the Company’s revenue is related to leasing activities, the adoption of this guidance will not have a material impact on the consolidated financial statements.

Property Acquisition

Property Acquisition	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Property Acquisition	Property Acquisitions During the three months ended March 31, 2017 , we did not acquire any properties from a third party.

Property Disposition

Property Disposition	3 Months Ended
	Mar. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Properties Held for Sale and Property Dispositions	Properties Held for Sale and Property Dispositions Properties Held for Sale During the three months ended March 31, 2017 , we entered into agreements to sell a 90% interest in 102 Greene Street and to sell the property at 520 White Plains Road in Tarrytown, New York. We recorded a $14.2 million depreciable real estate reserve in connection with the sale of 520 White Plains Road. In April 2017, we closed on the sale of 520 White Plains Road and the 90% interest in 102 Greene Street.

Debt and Preferred Equity Inves

Debt and Preferred Equity Investments	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Debt, Preferred Equity and Other Investments	Debt and Preferred Equity Investments During the three months ended March 31, 2017 and 2016 , our debt and preferred equity investments, net of discounts and deferred origination fees, increased by $403.9 million and $128.8 million , respectively, due to originations, purchases, advances under future funding obligations, discount and fee amortization, and paid-in-kind interest, net of premium amortization. We recorded repayments, participations and sales of $416.5 million and $420.2 million during the three months ended March 31, 2017 and 2016 , respectively, which offset the increases in debt and preferred equity investments. Certain participations in debt investments that were sold or syndicated did not meet the conditions for sale accounting are included in other assets and other liabilities on the consolidated balance sheets. Debt Investments As of March 31, 2017 and December 31, 2016 , we held the following debt investments, with an aggregate weighted average current yield of 9.42% at March 31, 2017 (in thousands): Loan Type March 31, 2017 Future Funding Obligations March 31, 2017 Senior March 31, 2017 (1) December 31, 2016 Carrying Value (1) Maturity Date (2) Fixed Rate Investments: Mezzanine Loan (3a) — 502,100 66,197 66,129 June 2017 Mortgage Loan (4) — — 26,324 26,311 February 2019 Mortgage Loan — — 346 380 August 2019 Mezzanine Loan — 1,160,000 197,358 — March 2020 Mezzanine Loan — 15,000 3,500 3,500 September 2021 Mezzanine Loan — 87,891 12,694 12,692 November 2023 Mezzanine Loan (3b) — 115,000 12,926 12,925 June 2024 Mezzanine Loan — 95,000 30,000 30,000 January 2025 Mezzanine Loan — 340,000 15,000 15,000 November 2026 Jr. Mortgage Participation/Mezzanine Loan (5) — — — 193,422 Total fixed rate $ — $ 2,314,991 $ 364,345 $ 360,359 Floating Rate Investments: Mezzanine Loan (3c) — 40,000 15,446 15,369 June 2017 Mortgage/ Mezzanine Loan — — 32,929 32,847 June 2017 Mortgage/Mezzanine Loan — — 22,978 22,959 July 2017 Mortgage/Mezzanine Loan — — 16,975 16,960 September 2017 Mortgage/Mezzanine Loan 2,302 — 21,630 20,423 October 2017 Mezzanine Loan — 60,000 14,970 14,957 November 2017 Mezzanine Loan (3d) — 85,000 15,206 15,141 December 2017 Mezzanine Loan (3e) — 65,000 14,714 14,656 December 2017 Mortgage/Mezzanine Loan (3f) 795 — 15,078 15,051 December 2017 Mortgage/Mezzanine Loan (6) — 125,000 29,902 29,998 January 2018 Mezzanine Loan — 40,000 19,930 19,913 April 2018 Jr. Mortgage Participation — 175,000 34,873 34,844 April 2018 Mezzanine Loan 523 20,523 10,880 10,863 August 2018 Mortgage/Mezzanine Loan — — 19,864 19,840 August 2018 Mortgage Loan — 65,000 14,898 14,880 August 2018 Mezzanine Loan — 37,500 14,698 14,648 September 2018 Loan Type March 31, 2017 Future Funding Obligations March 31, 2017 Senior March 31, 2017 (1) December 31, 2016 Carrying Value (1) Maturity Date (2) Mezzanine Loan 2,325 45,025 34,593 34,502 October 2018 Mezzanine Loan — 335,000 74,543 74,476 November 2018 Mezzanine Loan — 33,000 26,868 26,850 December 2018 Mezzanine Loan 2,005 169,152 57,496 56,114 December 2018 Mezzanine Loan 14,191 265,704 64,870 63,137 December 2018 Mezzanine Loan 11,177 210,770 68,136 64,505 December 2018 Mezzanine Loan — 45,000 12,120 12,104 January 2019 Mortgage/Mezzanine Loan 42,548 — 171,352 — January 2019 Mezzanine Loan 6,383 16,383 5,434 5,410 January 2019 Mezzanine Loan — 38,000 21,903 21,891 March 2019 Mezzanine Loan — 265,000 24,736 24,707 April 2019 Mortgage/Jr. Mortgage Participation Loan 32,721 185,649 66,484 65,554 August 2019 Mezzanine Loan 2,500 187,500 37,337 37,322 September 2019 Mortgage/Mezzanine Loan 75,310 — 119,422 111,819 September 2019 Mortgage/Mezzanine Loan 35,630 — 33,714 33,682 January 2020 Mezzanine Loan (7) 13,273 502,066 65,993 125,911 January 2020 Jr. Mortgage Participation/Mezzanine Loan — 60,000 15,613 15,606 July 2021 Mortgage/Mezzanine Loan (8) — — — 145,239 Total floating rate $ 241,683 $ 3,071,272 $ 1,215,585 $ 1,232,178 Total $ 241,683 $ 5,386,263 $ 1,579,930 $ 1,592,537 (1) Carrying value is net of discounts, premiums, original issue discounts and deferred origination fees. (2) Represents contractual maturity, excluding any unexercised extension options. (3) Carrying value is net of the following amounts that were sold or syndicated, which are included in other assets and other liabilities on the consolidated balance sheets as a result of the transfers not meeting the conditions for sale accounting: (a) $41.3 million , (b) $12.0 million , (c) $14.5 million , (d) $14.6 million , (e) $14.1 million , and (f) $5.1 million . (4) In September 2014, we acquired a $26.4 million mortgage loan at a $0.2 million discount and a $5.7 million junior mortgage participation at a $5.7 million discount. The junior mortgage participation was a nonperforming loan at acquisition, is currently on non-accrual status and has no carrying value. (5) This loan was repaid in March 2017. (6) This loan was extended in January 2017. (7) $66.1 million of outstanding principal was syndicated in February 2017. (8) This loan was repaid in January 2017. Preferred Equity Investments As of March 31, 2017 and December 31, 2016 , we held the following preferred equity investments with an aggregate weighted average current yield of 8.36% at March 31, 2017 (in thousands): Type March 31, 2017 March 31, 2017 March 31, 2017 (1) December 31, 2016 (1) Mandatory Redemption (2) Preferred Equity $ — $ 73,448 $ 9,986 $ 9,982 March 2018 Preferred Equity — 58,617 37,920 37,893 November 2018 Total $ — $ 132,065 $ 47,906 $ 47,875 (1) Carrying value is net of deferred origination fees. (2) Represents contractual maturity, excluding any unexercised extension options. At March 31, 2017 and December 31, 2016 , all debt and preferred equity investments were performing in accordance with the terms of the relevant investments, with the exception of a junior mortgage participation acquired in September 2014, which was acquired for zero and has a carrying value of zero , as further discussed in subnote 4 of the Debt Investments table above. We have determined that we have one portfolio segment of financing receivables at March 31, 2017 and 2016 comprising commercial real estate which is primarily recorded in debt and preferred equity investments. Included in other assets is an additional amount of financing receivables totaling $119.4 million and $144.5 million at March 31, 2017 and December 31, 2016 , respectively. No financing receivables were 90 days past due at March 31, 2017 .

Investments in Unconsolidated J

Investments in Unconsolidated Joint Ventures	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures We have investments in several real estate joint ventures with various partners. As of March 31, 2017 none of our investments in unconsolidated joint ventures are VIEs. The table below provides general information on each of our joint ventures as of March 31, 2017 : Property Partner Ownership Interest (1) Economic Interest (1) Approximate Square Feet Acquisition Date (2) Acquisition Price (2) (in thousands) 131-137 Spring Street Invesco Real Estate 20.00% 20.00% 68,342 August 2015 $ 277,750 76 11th Avenue (3) Oxford/Vornado 33.33% 35.09% 764,000 March 2016 138,240 (1) Ownership interest and economic interest represent the Company's interests in the joint venture as of March 31, 2017 . Changes in ownership or economic interests, if any, within the current year are disclosed in the notes below. (2) Acquisition date and price represent the date on which the Company initially acquired an interest in the joint venture and the actual or implied gross purchase price for the joint venture on that date. Acquisition date and price are not adjusted for subsequent acquisitions or dispositions of interest. (3) The joint venture owns two mezzanine notes secured by interests in the entity that owns 76 11th Avenue. The difference between our ownership interest and our economic interest results from our right to 50% of the total exit fee while each of our partners is entitled to receive 25% of the total exit fee and our right to 38% of the total extension fee while each of our partners is entitled to receive 31% of the total extension fee. Acquisition, Development and Construction Arrangements Based on the characteristics of the following arrangements, which are similar to those of an investment, combined with the expected residual profit of not greater than 50% , we have accounted for these debt and preferred equity investments under the equity method. As of March 31, 2017 and December 31, 2016 , the carrying value for acquisition, development and construction arrangements were as follows (in thousands): Loan Type March 31, 2017 December 31, 2016 Maturity Date Mezzanine Loan and Preferred Equity (1) $ 100,000 $ 100,000 March 2018 Mezzanine Loan (2) 24,965 24,542 July 2036 $ 124,965 $ 124,542 (1) These loans were extended in February 2017. (2) The Company has the ability to convert this loan into an equity position starting in 2021 and the borrower is able to force this conversion in 2024. Sale of Joint Venture Interests or Properties We did not sell any joint venture interest or property during the three months ended March 31, 2017 . Joint Venture Mortgages and Other Loans Payable We generally finance our joint ventures with non-recourse debt. In certain cases we may provide guarantees or master leases for tenant space, which terminate upon the satisfaction of specified circumstances or repayment of the underlying loans. The first mortgage notes and other loans payable collateralized by the respective joint venture properties and assignment of leases at March 31, 2017 and December 31, 2016 , respectively, are as follows (amounts in thousands): Property Maturity Date Interest Rate (1) March 31, 2017 December 31, 2016 Floating Rate Debt: 131-137 Spring Street August 2020 2.33 % $ 141,000 $ 141,000 Total joint venture mortgages and other loans payable $ 141,000 $ 141,000 Property Maturity Date Interest Rate (1) March 31, 2017 December 31, 2016 Deferred financing costs, net (3,693 ) (3,970 ) Total joint venture mortgages and other loans payable, net $ 137,307 $ 137,030 (1) Effective weighted average interest rate for the three months ended March 31, 2017 , taking into account interest rate hedges in effect during the period. The combined balance sheets for the unconsolidated joint ventures, at March 31, 2017 and December 31, 2016 are as follows (in thousands): March 31, 2017 December 31, 2016 Assets Commercial real estate property, net $ 277,866 $ 279,451 Debt and preferred equity investments, net 274,741 273,749 Other assets 18,005 18,922 Total assets $ 570,612 $ 572,122 Liabilities and members' equity Mortgages and other loans payable, net $ 137,307 $ 137,030 Other liabilities 20,973 22,185 Members' equity 412,332 412,907 Total liabilities and members' equity $ 570,612 $ 572,122 Company's investments in unconsolidated joint ventures $ 174,678 $ 174,127 The combined statements of operations for the unconsolidated joint ventures for the three months ended March 31, 2017 and 2016 , are as follows (in thousands): Three Months Ended March 31, 2017 2016 Total revenues $ 11,249 $ 6,937 Operating expenses 211 374 Real estate taxes 313 283 Interest expense, net of interest income 825 698 Amortization of deferred financing costs 277 277 Transaction related costs — — Depreciation and amortization 2,101 2,101 Total expenses $ 3,727 $ 3,733 Net income $ 7,522 $ 3,204 Company's equity in net income from unconsolidated joint ventures 4,255 2,457

Mortgages and Other Loans Payab

Mortgages and Other Loans Payable	3 Months Ended
	Mar. 31, 2017
Mortgage Note and Other Loans Payable
Mortgages and Other Loans Payable	Mortgages and Other Loans Payable The first mortgages and other loans payable collateralized by the respective properties and assignment of leases or debt investments at March 31, 2017 and December 31, 2016 , respectively, were as follows (amounts in thousands): Property Maturity Date Interest Rate (1) March 31, 2017 December 31, 2016 Fixed Rate Debt: 919 Third Avenue (2) June 2023 5.12 % $ 500,000 $ 500,000 315 West 33rd Street February 2027 4.24 % 250,000 — Floating Rate Debt: Master Repurchase Agreement July 2018 3.28 % $ 184,642 $ 184,642 Total mortgages and other loans payable $ 934,642 $ 684,642 Deferred financing costs, net of amortization (14,040 ) (8,574 ) Total mortgages and other loans payable, net $ 920,602 $ 676,068 (1) Effective weighted average interest rate for the three months ended March 31, 2017 . (2) We own a 51.0% controlling interest in the joint venture that is the borrower on this loan. Master Repurchase Agreement In July 2016, we entered into a restated Master Repurchase Agreement, or MRA, which provides us with the ability to sell certain debt investments with a simultaneous agreement to repurchase the same at a certain date or on demand. The MRA has a maximum facility capacity of $300.0 million and bears interest ranging from 225 and 400 basis points over 30-day LIBOR depending on the pledged collateral. Since December 6, 2015, we have been required to pay monthly in arrears a 25 basis point fee on the excess of $150.0 million over the average daily balance during the period if the average daily balance is less than $150.0 million . We seek to mitigate risks associated with our repurchase agreement by managing the credit quality of our assets, early repayments, interest rate volatility, liquidity, and market value. The margin call provisions under our repurchase facility permit valuation adjustments based on capital markets activity, and are not limited to collateral-specific credit marks. To monitor credit risk associated with our debt investments, our asset management team regularly reviews our investment portfolio and is in contact with our borrowers in order to monitor the collateral and enforce our rights as necessary. The risk associated with potential margin calls is further mitigated by our ability to recollateralize the facility with additional assets from our portfolio of debt investments, our ability to satisfy margin calls with cash or cash equivalents and our access to additional liquidity through the 2012 credit facility, as defined below. At March 31, 2017 and December 31, 2016 , the gross book value of the properties and debt and preferred equity investments collateralizing the mortgages and other loans payable, not including assets held for sale, was approximately $2.3 billion and $1.7 billion , respectively.

Corporate Indebtedness

Corporate Indebtedness	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Corporate Indebtedness	Corporate Indebtedness 2012 Credit Facility In August 2016, we entered into an amendment to the credit facility that was originally entered into by the Company in November 2012, referred to as the 2012 credit facility. As of March 31, 2017 , the 2012 credit facility, as amended, consisted of a $1.6 billion revolving credit facility and a $1.2 billion term loan, with a maturity date of March 29, 2019 and June 30, 2019, respectively. The revolving credit facility has an as-of-right extension to March 29, 2020. We also have an option, subject to customary conditions, to increase the capacity under the revolving credit facility to $3.0 billion at any time prior to the maturity date for the revolving credit facility without the consent of existing lenders, by obtaining additional commitments from our existing lenders and other financial institutions. As of March 31, 2017 , the 2012 credit facility bore interest at a spread over LIBOR ranging from (i) 87.5 basis points to 155 basis points for loans under the revolving credit facility and (ii) 95 basis points to 190 basis points for loans under the term loan facility, in each case based on the credit rating assigned to the senior unsecured long term indebtedness of ROP. At March 31, 2017 , the applicable spread was 125 basis points for the revolving credit facility and 140 basis points for the term loan facility. At March 31, 2017 , the effective interest rate was 2.03% for the revolving credit facility and 2.18% for the term loan facility. We are required to pay quarterly in arrears a 12.5 to 30 basis point facility fee on the total commitments under the revolving credit facility based on the credit rating assigned to the senior unsecured long term indebtedness of ROP. As of March 31, 2017 , the facility fee was 25 basis points. As of March 31, 2017 , we had $84.8 million of outstanding letters of credit, zero drawn under the revolving credit facility and $1.2 billion outstanding under the term loan facility, with total undrawn capacity of $1.5 billion under the 2012 credit facility. At March 31, 2017 and December 31, 2016 , the revolving credit facility had a carrying value of $(5.6) million , representing deferred financing costs presented within other liabilities, and $(6.3) million , respectively, net of deferred financing costs. At March 31, 2017 and December 31, 2016 , the term loan facility had a carrying value of $1.2 billion and $1.2 billion , respectively, net of deferred financing costs. We, SL Green and the Operating Partnership are all borrowers jointly and severally obligated under the 2012 credit facility. None of SL Green's other subsidiaries are obligors under the 2012 credit facility. The 2012 credit facility includes certain restrictions and covenants (see Restrictive Covenants below). Senior Unsecured Notes The following table sets forth our senior unsecured notes and other related disclosures as of March 31, 2017 and December 31, 2016 , respectively, by scheduled maturity date (dollars in thousands): Issuance March 31, March 31, December 31, Coupon (1) Effective Term Maturity Date August 5, 2011 (2) $ 250,000 $ 249,898 $ 249,880 5.00 % 5.00 % 7 August 2018 March 16, 2010 (2) 250,000 250,000 250,000 7.75 % 7.75 % 10 March 2020 November 15, 2012 (2) 200,000 200,000 200,000 4.50 % 4.50 % 10 December 2022 December 17, 2015 (2) 100,000 100,000 100,000 4.27 % 4.27 % 10 December 2025 $ 800,000 $ 799,898 $ 799,880 Deferred financing costs, net (4,296 ) (4,620 ) $ 800,000 $ 795,602 $ 795,260 (1) Interest on the senior unsecured notes is payable semi-annually with principal and unpaid interest due on the scheduled maturity dates. (2) Issued by SL Green, the Operating Partnership and ROP, as co-obligors. ROP also provides a guaranty of the Operating Partnership's obligations under its 3.00% Exchangeable Senior Notes due 2017. Restrictive Covenants The terms of the 2012 credit facility, as amended, and certain of our senior unsecured notes include certain restrictions and covenants which may limit, among other things, SL Green's ability to pay dividends, make certain types of investments, incur additional indebtedness, incur liens and enter into negative pledge agreements and dispose of assets, and which require compliance with financial ratios relating to the maximum ratio of total indebtedness to total asset value, a minimum ratio of EBITDA to fixed charges, a maximum ratio of secured indebtedness to total asset value and a maximum ratio of unsecured indebtedness to unencumbered asset value. The dividend restriction referred to above provides that SL Green will not during any time when a default is continuing, make distributions with respect to SL Green's common stock or other equity interests, except to enable SL Green to continue to qualify as a REIT for Federal income tax purposes. As of March 31, 2017 and 2016 , we were in compliance with all such covenants. Principal Maturities Combined aggregate principal maturities of our mortgage and other loans payable, 2012 credit facility and senior unsecured notes as of March 31, 2017 , including as-of-right extension options and put options, were as follows (in thousands): Scheduled Principal Revolving Unsecured Term Loan Senior Unsecured Notes Total Remaining 2017 $ — $ — $ — $ — $ — $ — 2018 — 184,642 — — 250,000 434,642 2019 — — — 1,183,000 — 1,183,000 2020 — — — — 250,000 250,000 2021 — — — — — — Thereafter — 750,000 — — 300,000 1,050,000 $ — $ 934,642 $ — $ 1,183,000 $ 800,000 $ 2,917,642 Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended March 31, 2017 2016 Interest expense before capitalized interest $ 29,851 $ 32,314 Interest capitalized (380 ) (109 ) Interest income (4 ) (4 ) Interest expense, net $ 29,467 $ 32,201

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Cleaning/ Security/ Messenger and Restoration Services Alliance Building Services, or Alliance, and its affiliates are partially owned by Gary Green, a son of Stephen L. Green, the chairman of SL Green's board of directors, and provide services to certain properties owned by us. Alliance’s affiliates include First Quality Maintenance, L.P., or First Quality, Classic Security LLC, Bright Star Couriers LLC and Onyx Restoration Works, and provide cleaning, extermination, security, messenger, and restoration services, respectively. In addition, First Quality has the non-exclusive opportunity to provide cleaning and related services to individual tenants at our properties on a basis separately negotiated with any tenant seeking such additional services. The Service Corporation has entered into an arrangement with Alliance whereby it will receive a profit participation above a certain threshold for services provided by Alliance to certain tenants at certain buildings above the base services specified in their lease agreements. Income earned from profit participation, which is included in other income on the consolidated statements of operations, was $0.8 million and $0.8 million for the three months ended March 31, 2017 and 2016 , respectively. We also recorded expenses for these services, inclusive of capitalized expenses, of $2.0 million and $1.7 million for the three months ended March 31, 2017 and 2016 , respectively, for these services (excluding services provided directly to tenants). Allocated Expenses from SL Green Property operating expenses include an allocation of salary and other operating costs from SL Green based on square footage of the related properties. Such amount was approximately $3.2 million and $2.6 million for the three months ended March 31, 2017 and 2016 , respectively. Insurance We obtained insurance coverage through an insurance program administered by SL Green. In connection with this program, we incurred insurance expense of approximately $1.4 million and $1.6 million for the three months ended March 31, 2017 and 2016 , respectively.

Preferred Units

Preferred Units	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Preferred Units	Preferred Units Through a consolidated subsidiary, we have authorized up to 109,161 3.5% Series A Preferred Units of limited partnership interest, or the Greene Series A Preferred Units, with a liquidation preference of $1,000.00 per unit. In August 2015, the Company issued 109,161 Greene Series A Preferred Units in conjunction with an acquisition. The Greene Series A Preferred unitholders receive annual dividends of $35.00 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Greene Series A Preferred Units can be redeemed at any time, at the option of the unitholder, either for cash or are convertible on a one-for-one basis, into the Series B Preferred Units of limited partnership interest, or the Greene Series B Preferred Units. The Greene Series B Preferred Units can be converted at any time, at the option of the unitholder, into a number of common stock equal to 6.71348 shares of SL Green common stock for each Greene Series B Preferred Unit. As of March 31, 2017 , no Greene Series B Preferred Units have been issued. ASC 815 Derivatives and Hedging requires bifurcation of certain embedded derivative instruments, such as conversion features in convertible equity instruments, and their measurement at fair value for accounting purposes. The conversion feature embedded in the Subsidiary Series A Preferred Units was evaluated, and it was determined that the conversion feature should be bifurcated from its host instrument and accounted for as a freestanding derivative. The derivative is reported as a derivative liability in accrued interest and other liabilities on the accompanying consolidated balance sheet and is adjusted to its fair value at each reporting date, with a corresponding adjustment to interest expense, net of interest income. The embedded derivative for the Subsidiary Series A Preferred Units was initially recorded at a fair value of zero on July 22, 2015, the date of issuance. At December 31, 2016, the carrying amount of the derivative was adjusted to its fair value of zero , with a corresponding adjustment to preferred units and interest expense, net of interest income. At March 31, 2017 the carrying amount and fair value of the derivative remained at zero .

Partners' Capital

Partners' Capital	3 Months Ended
	Mar. 31, 2017
Partners' Capital Notes [Abstract]
Partners' Capital	Partners' Capital Since consummation of the Merger on January 25, 2007, the Operating Partnership has owned all the economic interests in ROP either by direct ownership or by indirect ownership through our general partner, which is its wholly-owned subsidiary. Intercompany transactions between SL Green and ROP are generally recorded as contributions and distributions.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We are required to disclose fair value information with regard to our financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practical to estimate fair value. The FASB guidance defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. We measure and/or disclose the estimated fair value of financial assets and liabilities based on a hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consists of three broad levels: Level 1 - quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date; Level 2 - inputs other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly; and Level 3 - unobservable inputs for the asset or liability that are used when little or no market data is available. We follow this hierarchy for our assets and liabilities measured at fair value on a recurring and nonrecurring basis. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. Our assessment of the significance of the particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. We determine other than temporary impairment in real estate investments and debt and preferred equity investments, including intangibles primarily utilizing cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, as well as sales comparison approach, which utilizes comparable sales, listings and sales contracts. All of which are classified as Level 3 inputs. The fair value of derivative instruments is based on current market data received from financial sources that trade such instruments and are based on prevailing market data and derived from third party proprietary models based on well-recognized financial principles and reasonable estimates about relevant future market conditions, which are classified as Level 2 inputs. The financial assets and liabilities that are not measured at fair value on our consolidated balance sheets include cash and cash equivalents, restricted cash, accounts receivable, accounts payable and accrued expenses, debt and preferred equity investments, mortgages and other loans payable and other secured and unsecured debt. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, and accounts payable and accrued expenses reported in our consolidated balance sheets approximates fair value due to the short term nature of these instruments. The fair value of debt and preferred equity investments, which is classified as Level 3, is estimated by discounting the future cash flows using current interest rates at which similar loans with the same maturities would be made to borrowers with similar credit ratings. The fair value of borrowings, which is classified as Level 3, is estimated by discounting the contractual cash flows of each debt instrument to their present value using adjusted market interest rates, which is provided by a third-party specialist. The following table provides the carrying value and fair value of these financial instruments as of March 31, 2017 and December 31, 2016 (in thousands): March 31, 2017 December 31, 2016 Carrying Value (1) Fair Value Carrying Value (1) Fair Value Debt and preferred equity investments (2) $ 1,627,836 (3) $ 1,640,412 (3) Fixed rate debt $ 2,349,898 $ 2,438,513 $ 2,099,880 $ 2,183,042 Variable rate debt 567,642 578,410 567,642 580,083 $ 2,917,540 $ 3,016,923 $ 2,667,522 $ 2,763,125 (1) Amounts exclude net deferred financing costs. (2) Excludes investments with a book value of $174.7 million and $174.1 million as of March 31, 2017 and December 31, 2016 , respectively, which we accounted for under the equity method accounting as a result of meeting criteria of a real estate investment under the guidance for Acquisition, Development and Construction arrangements, and other investments with a book value of $119.4 million and $144.5 million as of March 31, 2017 and December 31, 2016 , respectively. (3) At March 31, 2017 , debt and preferred equity investments had an estimated fair value ranging between $1.6 billion and $1.8 billion . At December 31, 2016 , debt and preferred equity investments had an estimated fair value ranging between $1.6 billion and $1.8 billion . Disclosure about fair value of financial instruments was based on pertinent information available to us as of March 31, 2017 and December 31, 2016 . Although we are not aware of any factors that would significantly affect the reasonable fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since that date and current estimates of fair value may differ significantly from the amounts presented herein.

Financial Instruments_ Derivati

Financial Instruments: Derivatives and Hedging	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments: Derivatives and Hedging	Financial Instruments: Derivatives and Hedging In the normal course of business, we use a variety of commonly used derivative instruments, such as interest rate swaps, caps, collar and floors, to manage, or hedge interest rate risk. We hedge our exposure to variability in future cash flows for forecasted transactions in addition to anticipated future interest payments on existing debt. We recognize all derivatives on the balance sheets at fair value. Derivatives that are not hedges are adjusted to fair value through earnings. If a derivative is a hedge, depending on the nature of the hedge, changes in the fair value of the derivative will either be offset against the change in fair value of the hedge asset, liability, or firm commitment through earnings, or recognized in other comprehensive income until the hedged item is recognized in earnings. The ineffective portion of a derivative's change in fair value will be immediately recognized in earnings. Reported net income and equity may increase or decrease prospectively, depending on future levels of interest rates and other variables affecting the fair values of derivative instruments and hedged items, but will have no effect on cash flows. Currently, all of our designated derivative instruments are effective hedging instruments. As of March 31, 2017 , the Company had not designated any interest rate swap agreements on any debt investment. Gains and losses on terminated hedges are included in accumulated other comprehensive loss, and are recognized into earnings over the term of the related senior unsecured notes. As of March 31, 2017 and December 31, 2016 , the deferred net losses from these terminated hedges, which are included in accumulated other comprehensive loss relating to net unrealized loss on derivative instruments, was approximately $1.5 million and $1.6 million , respectively. Over time, the realized and unrealized gains and losses held in accumulated other comprehensive loss will be reclassified into earnings as an adjustment to interest expense in the same periods in which the hedged interest payments affect earnings. We estimate that approximately $0.4 million of the current balance held in accumulated other comprehensive loss will be reclassified into interest expense within the next 12 months. The following table presents the effect of our derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the three months ended March 31, 2017 and 2016 , respectively (in thousands): Amount of Loss Recognized in Other Comprehensive Loss (Effective Portion) Location of Loss Reclassified from Accumulated Other Comprehensive Loss into Income Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Location of Gain Recognized in Income on Derivative Amount of Gain Recognized into Income (Ineffective Portion) Three Months Ended March 31, Three Months Ended March 31, Three Months Ended March 31, Derivative 2017 2016 2017 2016 2017 2016 Interest Rate Swap $ — $ (12 ) Interest expense $ 90 $ 232 Interest expense $ — $ 2

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings As of March 31, 2017 , we were not involved in any material litigation nor, to management's knowledge, was any material litigation threatened against us or our portfolio which if adversely determined could have a material adverse impact on us. Guarantees During the year ended December 31, 2015 , Belmont Insurance Company, or Belmont, a New York licensed captive insurance company and an affiliate of SL Green, became a member of the Federal Home Loan Bank of New York, or FHLBNY. As a member, Belmont could borrow funds from the FHLBNY in the form of secured advances. As of December 31, 2016 , certain commercial real estate properties and debt and preferred equity investments of the Company were pledged as collateral to secure advances under the FHLBNY facility. Belmont's membership was terminated on February 20, 2017 and all funds borrowed from the FHLBNY were repaid in January 2017. Environmental Matters Our management believes that the properties are in compliance in all material respects with applicable Federal, state and local ordinances and regulations regarding environmental issues. Management is not aware of any environmental liability that it believes would have a materially adverse impact on our financial position, results of operations or cash flows. Management is unaware of any instances in which it would incur significant environmental cost if any of our properties were sold. Ground Leases Arrangements The following is a schedule of future minimum lease payments under non-cancellable operating leases with initial terms in excess of one year as of March 31, 2017 (in thousands): Non-cancellable operating leases Remaining 2017 $ 15,440 2018 20,586 2019 20,586 2020 20,586 2021 20,736 Thereafter 308,202 Total minimum lease payments $ 406,136

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information We are engaged in acquiring, owning, managing and leasing commercial properties in Manhattan, Brooklyn, Westchester County, Connecticut and New Jersey and have two reportable segments, real estate and debt and preferred equity investments. We evaluate real estate performance and allocate resources based on earnings contribution to income from continuing operations. The primary sources of revenue are generated from tenant rents and escalations and reimbursement revenue. Real estate property operating expenses consist primarily of security, maintenance, utility costs, real estate taxes and ground rent expense (at certain applicable properties). See Note 5, "Debt and Preferred Equity Investments," for additional details on our debt and preferred equity investments. Selected consolidated results of operations for the three months ended March 31, 2017 and 2016 , and selected asset information as of March 31, 2017 and December 31, 2016 , regarding our operating segments are as follows (in thousands): Real Estate Segment Debt and Preferred Equity Segment Total Company Total revenues: Three months ended: March 31, 2017 $ 185,019 $ 47,336 $ 232,355 March 31, 2016 178,783 60,881 239,664 (Loss) income from continuing operations before equity in net gain on sale of interest from unconsolidated joint venture/real estate and depreciable real estate reserves: Three months ended: March 31, 2017 $ (29,259 ) $ 40,401 $ 11,142 March 31, 2016 18,460 53,740 72,200 Total assets As of: March 31, 2017 $ 6,692,595 $ 1,932,175 $ 8,624,770 December 31, 2016 6,786,479 1,968,134 8,754,613 Income from continuing operations represents total revenues less total expenses for the real estate segment and total investment income less allocated interest expense for the debt and preferred equity segment. Interest costs for the debt and preferred equity segment includes actual costs incurred for investments collateralizing the MRA. Interest is imputed on the remaining investments using our corporate borrowing cost. We also allocate loan loss reserves, net of recoveries and transaction related costs to the debt and preferred equity segment. We do not allocate marketing, general and administrative expenses to the debt and preferred equity segment since the use of personnel and resources is dependent on transaction volume between the two segments and varies period over period. In addition, we base performance on the individual segments prior to allocating marketing, general and administrative expenses. For the three months ended March 31, 2017 , and 2016 , marketing, general and administrative expenses totaled $0.1 million and $0.2 million , respectively. All other expenses, except interest, relate entirely to the real estate assets. There were no transactions between the above two segments.

Significant Accounting Polici24

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include our accounts and those of our subsidiaries, which are wholly-owned or controlled by us. Entities which we do not control through our voting interest and entities which are variable interest entities, but where we are not the primary beneficiary, are accounted for under the equity method. See Note 5, "Debt and Preferred Equity Investments" and Note 6, "Investments in Unconsolidated Joint Ventures." All significant intercompany balances and transactions have been eliminated. We consolidate a variable interest entity, or VIE, in which we are considered the primary beneficiary. The primary beneficiary is the entity that has (i) the power to direct the activities that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. Included in commercial real estate properties on our consolidated balance sheets as of March 31, 2017 and December 31, 2016 are $1.4 billion and $1.4 billion , respectively, related to our consolidated VIEs. Included in mortgages and other loans payable on our consolidated balance sheets as of March 31, 2017 and December 31, 2016 are $494.3 million and $494.1 million, respectively, related to our consolidated VIEs.
Investment in Commercial Real Estate Properties	Investment in Commercial Real Estate Properties On a periodic basis, we assess whether there are any indications that the value of our real estate properties may be other than temporarily impaired or that their carrying value may not be recoverable. A property's value is considered impaired if management's estimate of the aggregate future cash flows (undiscounted) to be generated by the property is less than the carrying value of the property. To the extent impairment has occurred, the loss will be measured as the excess of the carrying amount of the property over the calculated fair value of the property. We also evaluate our real estate properties for potential impairment when a real estate property has been classified as held for sale. Real estate assets held for sale are valued at the lower of either their carrying value or fair value less costs to sell. We do not believe that there were any indicators of impairment at any of our consolidated properties at March 31, 2017 except for 520 White Plains Road in Tarrytown, New York, and 680/750 Washington Boulevard in Stamford, Connecticut, for which we recorded a $56.3 million depreciable real estate reserve during the three months ended March 31, 2017 . We allocate the purchase price of real estate to land and building (inclusive of tenant improvements) and, if determined to be material, intangibles, such as the value of above- and below-market leases and origination costs associated with the in-place leases. We depreciate the amount allocated to building (inclusive of tenant improvements) over their estimated useful lives, which generally range from three to 40 years . We amortize the amount allocated to the above- and below-market leases over the remaining term of the associated lease, which generally range from one to 14 years , and record it as either an increase (in the case of below-market leases) or a decrease (in the case of above-market leases) to rental income. We amortize the amount allocated to the values associated with in-place leases over the expected term of the associated lease, which generally ranges from one to 14 years . If a tenant vacates its space prior to the contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related intangible will be written off. The tenant improvements and origination costs are amortized as an expense over the remaining life of the lease (or charged against earnings if the lease is terminated prior to its contractual expiration date). We assess fair value of the leases based on estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends, and market/economic conditions that may affect the property. To the extent acquired leases contain fixed rate renewal options that are below-market and determined to be material, we amortize such below-market lease value into rental income over the renewal period.
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures We assess our investments in unconsolidated joint ventures for recoverability, and if it is determined that a loss in value of the investment is other than temporary, we write down the investment to its fair value. We evaluate our equity investments for impairment based on the joint ventures' projected discounted cash flows. We do not believe that the values of any of our equity investments were impaired at March 31, 2017 .
Reserve for Possible Credit Losses	Reserve for Possible Credit Losses The expense for possible credit losses in connection with debt and preferred equity investments is the charge to earnings to increase the allowance for possible credit losses to the level that we estimate to be adequate, based on Level 3 data, considering delinquencies, loss experience and collateral quality. Other factors considered include geographic trends, product diversification, the size of the portfolio and current economic conditions. Based upon these factors, we establish a provision for possible credit loss on each individual investment. When it is probable that we will be unable to collect all amounts contractually due, the investment is considered impaired. Where impairment is indicated on an investment that is held to maturity, a valuation allowance is measured based upon the excess of the recorded investment amount over the net fair value of the collateral. Any deficiency between the carrying amount of an asset and the calculated value of the collateral is charged to expense. We continue to assess or adjust our estimates based on circumstances of a loan and the underlying collateral. If additional information reflects increased recovery of our investment, we will adjust our reserves accordingly.
Income Taxes	Income Taxes ROP is a disregarded entity of SL Green Operating Partnership, L.P. for federal income tax purposes, and, as a result, all income and losses of ROP are considered income and losses of SL Green Operating Partnership, L. P. No provision has been made for income taxes in the consolidated financial statements since such taxes, if any, are the responsibility of the individual partners of SL Green Operating Partnership, L.P.
Shares Contributed by Parent Company	Shares Contributed by Parent Company We present shares of SL Green common stock as a contra-equity account in our financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash investments, debt and preferred equity investments and accounts receivable. We place our cash investments in excess of insured amounts with high quality financial institutions. The collateral securing our debt and preferred equity investments is located in New York City. See Note 5, "Debt and Preferred Equity Investments." We perform ongoing credit evaluations of our tenants and require most tenants to provide security deposits or letters of credit. Though these security deposits and letters of credit are insufficient to meet the total value of a tenant's lease obligation, they are a measure of good faith and a source of funds to offset the economic costs associated with lost revenue and the costs associated with re-tenanting a space. The properties in our real estate portfolio are primarily located in Manhattan. We also have properties located in Brooklyn, Westchester County, Connecticut and New Jersey. The tenants located in our buildings operate in various industries.
Reclassification	Reclassification Certain prior year balances have been reclassified to conform to our current year presentation.
Accounting Standards Updates	Accounting Standards Updates In February 2017, the FASB issued guidance to clarify the scope of Subtopic 610-20 as well as provide guidance on accounting for partial sales of nonfinancial assets. Subtopic 610-20 was issued in May 2014 as part of ASU 2014-09. The Company anticipates adopting this guidance January 1, 2018, and applying the cumulative-effect adoption method. The Company is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In January, 2017, the FASB issued Accounting Standards Update (ASU) No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business The guidance clarifies the definition of a business and provides guidance to assist with determining whether transactions should be accounted for as acquisitions of assets or businesses. The main provision is that an acquiree is not a business if substantially all of the fair value of the gross assets is concentrated in a single identifiable asset or group of assets. The Company adopted the guidance on the issuance date effective January 5, 2017. The Company expects that most of our real estate acquisitions will be considered asset acquisitions under the new guidance and that transaction costs will be capitalized to the investment basis which is then subject to a purchase price allocation based on relative fair value. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The guidance will require entities to show the changes on the total cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities will not longer present transfers between these items on the statement of cash flows. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Company has not yet adopted this new guidance and is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The ASU provides final guidance on eight cash flow issues, including debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, distributions received from equity method investees, separately identifiable cash flows and application of the predominance principle, and others. The amendments in the ASU are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted the guidance effective January 1, 2017 and there was no impact on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The guidance changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The guidance replaces the current ‘incurred loss’ model with an ‘expected loss’ approach. The guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted after December 2018. The Company has not yet adopted this new guidance and is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The guidance simplifies the accounting for share-based payment award transactions including: income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The guidance is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Company adopted the guidance effective January 1, 2017 and there was no material impact on the Company’s consolidated financial statements. In March 2016, the FASB issued ASU 2016-07, Investments Equity Method and Joint Ventures (Topic 323). The guidance eliminates the requirement that an entity retroactively adopt the equity method of accounting if an investment qualifies for use of the equity method as a result of an increase in the level of ownership or degree of influence. The amendments require that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted the guidance effective January 1, 2017 and there was no impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases. The guidance requires lessees to recognize lease assets and lease liabilities for those leases classified as operating leases under the previous standard. Depending on the lease classification, lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. The accounting applied by a lessor is largely unchanged from that applied under the previous standard. One of the impacts on the Company will be the presentation and disclosure in the financial statements of non-lease components such as charges to tenants for a building’s operating expenses. The non-lease components will be presented separately from the lease components in both the Consolidated Statements of Operations and Consolidated Balance Sheets. Another impact is the measurement and presentation of ground leases under which the Company is lessee. The Company is required to record a liability for the obligation to make payments under the lease and an asset for the right to use the underlying asset during the lease term and will also apply the new expense recognition requirements given the lease classification. The Company is currently quantifying these impacts. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company anticipates adopting this guidance January 1, 2019 and will apply the modified retrospective approach. In January 2016, the FASB issued ASU 2016-01 (ASU 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and to record changes in instruments-specific credit risk for financial liabilities measured under the fair value option in other comprehensive income. The guidance is effective for fiscal years beginning after December 15, 2017, and for interim periods therein. The Company has not yet adopted this new guidance and is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. In May 2014, the FASB issued a new comprehensive revenue recognition guidance which requires us to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods and services (ASU 2014-09). The guidance also requires enhanced disclosures to help users of financial statements better understand the nature, amount, timing, and uncertainty of revenue that is recognized. In March 2016, the FASB issued implementation guidance which clarifies principal versus agent considerations in reporting revenue gross versus net (ASU 2016-08). In April 2016, the FASB issued implementation guidance which clarifies the identification of performance obligations (ASU 2016-10). In April 2016, the FASB amended its new revenue recognition guidance on identifying performance obligations to allow entities to disregard items that are immaterial and clarify when a good or service is separately identifiable (ASU 2016-10). In May 2016, the FASB issued implementation guidance relating to transition, collectability, noncash consideration and presentation matters (ASU 2016-12). These ASUs are effective for annual and interim periods beginning after December 15, 2017. Early adoption is permitted but not before interim and annual reporting periods beginning after December 15, 2016. The new guidance can be applied either retrospectively to each prior reporting period presented, or as a cumulative-effect adjustment as of the date of adoption. The Company anticipates adopting this guidance January 1, 2018, and applying the cumulative-effect adoption method. Since the Company’s revenue is related to leasing activities, the adoption of this guidance will not have a material impact on the consolidated financial statements.
Fair Value Measurements	Fair Value Measurements We are required to disclose fair value information with regard to our financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practical to estimate fair value. The FASB guidance defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. We measure and/or disclose the estimated fair value of financial assets and liabilities based on a hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consists of three broad levels: Level 1 - quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date; Level 2 - inputs other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly; and Level 3 - unobservable inputs for the asset or liability that are used when little or no market data is available. We follow this hierarchy for our assets and liabilities measured at fair value on a recurring and nonrecurring basis. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. Our assessment of the significance of the particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. We determine other than temporary impairment in real estate investments and debt and preferred equity investments, including intangibles primarily utilizing cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, as well as sales comparison approach, which utilizes comparable sales, listings and sales contracts. All of which are classified as Level 3 inputs. The fair value of derivative instruments is based on current market data received from financial sources that trade such instruments and are based on prevailing market data and derived from third party proprietary models based on well-recognized financial principles and reasonable estimates about relevant future market conditions, which are classified as Level 2 inputs. The financial assets and liabilities that are not measured at fair value on our consolidated balance sheets include cash and cash equivalents, restricted cash, accounts receivable, accounts payable and accrued expenses, debt and preferred equity investments, mortgages and other loans payable and other secured and unsecured debt. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, and accounts payable and accrued expenses reported in our consolidated balance sheets approximates fair value due to the short term nature of these instruments. The fair value of debt and preferred equity investments, which is classified as Level 3, is estimated by discounting the future cash flows using current interest rates at which similar loans with the same maturities would be made to borrowers with similar credit ratings. The fair value of borrowings, which is classified as Level 3, is estimated by discounting the contractual cash flows of each debt instrument to their present value using adjusted market interest rates, which is provided by a third-party specialist.

Organization and Basis of Pre25

Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of commercial office properties	As of March 31, 2017 , we owned the following interests in properties in the New York Metropolitan area, primarily in midtown Manhattan. Our investments in the New York Metropolitan area also include investments in Brooklyn, Westchester County, Connecticut and New Jersey, which are collectively known as the Suburban properties: Location Type Number of Approximate Square Feet (unaudited) Weighted Average (1) (unaudited) Commercial: Manhattan Office 16 8,463,245 96.4 % Retail (2)(3)(4) 6 374,016 95.8 % Fee Interest 1 176,530 100.0 % 23 9,013,791 96.4 % Suburban Office (5) 18 3,251,000 83.0 % Retail 1 52,000 100.0 % 19 3,303,000 83.3 % Total commercial properties 42 12,316,791 92.9 % Residential: Manhattan Residential (2) — 222,855 94.0 % Total portfolio 42 12,539,646 92.9 % (1) The weighted average occupancy for commercial properties represents the total occupied square feet divided by total square footage at acquisition. The weighted average occupancy for residential properties represents the total occupied units divided by total available units. (2) As of March 31, 2017 , we owned a building that was comprised of approximately 270,132 square feet of retail space and approximately 222,855 square feet of residential space. For the purpose of this report, we have included the building in the number of retail properties we own. However, we have included only the retail square footage in the retail approximate square footage, and have listed the balance of the square footage as residential square footage. (3) Includes two unconsolidated joint venture retail properties at 131-137 Spring Street comprised of approximately 68,342 square feet. (4) Includes the property at 102 Greene Street, which is classified as held for sale at March 31, 2017. (5) Includes the property at 520 White Plains Road, which is classified as held for sale at March 31, 2017.

Significant Accounting Polici26

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Summary of identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases)	The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of March 31, 2017 and December 31, 2016 (in thousands): March 31, 2017 December 31, 2016 Identified intangible assets (included in other assets): Gross amount $ 309,678 $ 311,830 Accumulated amortization (254,821 ) (253,064 ) Net (1) $ 54,857 $ 58,766 Identified intangible liabilities (included in deferred revenue): Gross amount $ 521,873 $ 524,793 Accumulated amortization (372,100 ) (368,738 ) Net (1) $ 149,773 $ 156,055 (1) As of March 31, 2017 and December 31, 2016, $0.1 million and none , respectively and $0.1 million and none , respectively, of net intangible assets and net intangible liabilities, were reclassified to assets held for sale and liabilities related to assets held for sale.

Debt and Preferred Equity Inv27

Debt and Preferred Equity Investments (Tables)	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Summary of debt investments	As of March 31, 2017 and December 31, 2016 , we held the following debt investments, with an aggregate weighted average current yield of 9.42% at March 31, 2017 (in thousands): Loan Type March 31, 2017 Future Funding Obligations March 31, 2017 Senior March 31, 2017 (1) December 31, 2016 Carrying Value (1) Maturity Date (2) Fixed Rate Investments: Mezzanine Loan (3a) — 502,100 66,197 66,129 June 2017 Mortgage Loan (4) — — 26,324 26,311 February 2019 Mortgage Loan — — 346 380 August 2019 Mezzanine Loan — 1,160,000 197,358 — March 2020 Mezzanine Loan — 15,000 3,500 3,500 September 2021 Mezzanine Loan — 87,891 12,694 12,692 November 2023 Mezzanine Loan (3b) — 115,000 12,926 12,925 June 2024 Mezzanine Loan — 95,000 30,000 30,000 January 2025 Mezzanine Loan — 340,000 15,000 15,000 November 2026 Jr. Mortgage Participation/Mezzanine Loan (5) — — — 193,422 Total fixed rate $ — $ 2,314,991 $ 364,345 $ 360,359 Floating Rate Investments: Mezzanine Loan (3c) — 40,000 15,446 15,369 June 2017 Mortgage/ Mezzanine Loan — — 32,929 32,847 June 2017 Mortgage/Mezzanine Loan — — 22,978 22,959 July 2017 Mortgage/Mezzanine Loan — — 16,975 16,960 September 2017 Mortgage/Mezzanine Loan 2,302 — 21,630 20,423 October 2017 Mezzanine Loan — 60,000 14,970 14,957 November 2017 Mezzanine Loan (3d) — 85,000 15,206 15,141 December 2017 Mezzanine Loan (3e) — 65,000 14,714 14,656 December 2017 Mortgage/Mezzanine Loan (3f) 795 — 15,078 15,051 December 2017 Mortgage/Mezzanine Loan (6) — 125,000 29,902 29,998 January 2018 Mezzanine Loan — 40,000 19,930 19,913 April 2018 Jr. Mortgage Participation — 175,000 34,873 34,844 April 2018 Mezzanine Loan 523 20,523 10,880 10,863 August 2018 Mortgage/Mezzanine Loan — — 19,864 19,840 August 2018 Mortgage Loan — 65,000 14,898 14,880 August 2018 Mezzanine Loan — 37,500 14,698 14,648 September 2018 Loan Type March 31, 2017 Future Funding Obligations March 31, 2017 Senior March 31, 2017 (1) December 31, 2016 Carrying Value (1) Maturity Date (2) Mezzanine Loan 2,325 45,025 34,593 34,502 October 2018 Mezzanine Loan — 335,000 74,543 74,476 November 2018 Mezzanine Loan — 33,000 26,868 26,850 December 2018 Mezzanine Loan 2,005 169,152 57,496 56,114 December 2018 Mezzanine Loan 14,191 265,704 64,870 63,137 December 2018 Mezzanine Loan 11,177 210,770 68,136 64,505 December 2018 Mezzanine Loan — 45,000 12,120 12,104 January 2019 Mortgage/Mezzanine Loan 42,548 — 171,352 — January 2019 Mezzanine Loan 6,383 16,383 5,434 5,410 January 2019 Mezzanine Loan — 38,000 21,903 21,891 March 2019 Mezzanine Loan — 265,000 24,736 24,707 April 2019 Mortgage/Jr. Mortgage Participation Loan 32,721 185,649 66,484 65,554 August 2019 Mezzanine Loan 2,500 187,500 37,337 37,322 September 2019 Mortgage/Mezzanine Loan 75,310 — 119,422 111,819 September 2019 Mortgage/Mezzanine Loan 35,630 — 33,714 33,682 January 2020 Mezzanine Loan (7) 13,273 502,066 65,993 125,911 January 2020 Jr. Mortgage Participation/Mezzanine Loan — 60,000 15,613 15,606 July 2021 Mortgage/Mezzanine Loan (8) — — — 145,239 Total floating rate $ 241,683 $ 3,071,272 $ 1,215,585 $ 1,232,178 Total $ 241,683 $ 5,386,263 $ 1,579,930 $ 1,592,537 (1) Carrying value is net of discounts, premiums, original issue discounts and deferred origination fees. (2) Represents contractual maturity, excluding any unexercised extension options. (3) Carrying value is net of the following amounts that were sold or syndicated, which are included in other assets and other liabilities on the consolidated balance sheets as a result of the transfers not meeting the conditions for sale accounting: (a) $41.3 million , (b) $12.0 million , (c) $14.5 million , (d) $14.6 million , (e) $14.1 million , and (f) $5.1 million . (4) In September 2014, we acquired a $26.4 million mortgage loan at a $0.2 million discount and a $5.7 million junior mortgage participation at a $5.7 million discount. The junior mortgage participation was a nonperforming loan at acquisition, is currently on non-accrual status and has no carrying value. (5) This loan was repaid in March 2017. (6) This loan was extended in January 2017. (7) $66.1 million of outstanding principal was syndicated in February 2017. (8) This loan was repaid in January 2017.
Schedule of preferred equity investments	As of March 31, 2017 and December 31, 2016 , we held the following preferred equity investments with an aggregate weighted average current yield of 8.36% at March 31, 2017 (in thousands): Type March 31, 2017 March 31, 2017 March 31, 2017 (1) December 31, 2016 (1) Mandatory Redemption (2) Preferred Equity $ — $ 73,448 $ 9,986 $ 9,982 March 2018 Preferred Equity — 58,617 37,920 37,893 November 2018 Total $ — $ 132,065 $ 47,906 $ 47,875 (1) Carrying value is net of deferred origination fees. (2) Represents contractual maturity, excluding any unexercised extension options.

Investments in Unconsolidated28

Investments in Unconsolidated Joint Ventures (Tables)	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of general information on joint ventures	The table below provides general information on each of our joint ventures as of March 31, 2017 : Property Partner Ownership Interest (1) Economic Interest (1) Approximate Square Feet Acquisition Date (2) Acquisition Price (2) (in thousands) 131-137 Spring Street Invesco Real Estate 20.00% 20.00% 68,342 August 2015 $ 277,750 76 11th Avenue (3) Oxford/Vornado 33.33% 35.09% 764,000 March 2016 138,240 (1) Ownership interest and economic interest represent the Company's interests in the joint venture as of March 31, 2017 . Changes in ownership or economic interests, if any, within the current year are disclosed in the notes below. (2) Acquisition date and price represent the date on which the Company initially acquired an interest in the joint venture and the actual or implied gross purchase price for the joint venture on that date. Acquisition date and price are not adjusted for subsequent acquisitions or dispositions of interest. (3) The joint venture owns two mezzanine notes secured by interests in the entity that owns 76 11th Avenue. The difference between our ownership interest and our economic interest results from our right to 50% of the total exit fee while each of our partners is entitled to receive 25% of the total exit fee and our right to 38% of the total extension fee while each of our partners is entitled to receive 31% of the total extension fee. As of March 31, 2017 and December 31, 2016 , the carrying value for acquisition, development and construction arrangements were as follows (in thousands): Loan Type March 31, 2017 December 31, 2016 Maturity Date Mezzanine Loan and Preferred Equity (1) $ 100,000 $ 100,000 March 2018 Mezzanine Loan (2) 24,965 24,542 July 2036 $ 124,965 $ 124,542 (1) These loans were extended in February 2017. (2) The Company has the ability to convert this loan into an equity position starting in 2021 and the borrower is able to force this conversion in 2024.
Schedule of first mortgage notes payable collateralized by the respective joint venture properties and assignment of leases	The first mortgage notes and other loans payable collateralized by the respective joint venture properties and assignment of leases at March 31, 2017 and December 31, 2016 , respectively, are as follows (amounts in thousands): Property Maturity Date Interest Rate (1) March 31, 2017 December 31, 2016 Floating Rate Debt: 131-137 Spring Street August 2020 2.33 % $ 141,000 $ 141,000 Total joint venture mortgages and other loans payable $ 141,000 $ 141,000 Property Maturity Date Interest Rate (1) March 31, 2017 December 31, 2016 Deferred financing costs, net (3,693 ) (3,970 ) Total joint venture mortgages and other loans payable, net $ 137,307 $ 137,030 (1) Effective weighted average interest rate for the three months ended March 31, 2017 , taking into account interest rate hedges in effect during the period.
Schedule of combined balance sheets for the unconsolidated joint ventures	. The combined balance sheets for the unconsolidated joint ventures, at March 31, 2017 and December 31, 2016 are as follows (in thousands): March 31, 2017 December 31, 2016 Assets Commercial real estate property, net $ 277,866 $ 279,451 Debt and preferred equity investments, net 274,741 273,749 Other assets 18,005 18,922 Total assets $ 570,612 $ 572,122 Liabilities and members' equity Mortgages and other loans payable, net $ 137,307 $ 137,030 Other liabilities 20,973 22,185 Members' equity 412,332 412,907 Total liabilities and members' equity $ 570,612 $ 572,122 Company's investments in unconsolidated joint ventures $ 174,678 $ 174,127
Schedule of combined statements of operations for the unconsolidated joint ventures	March 31, 2017 December 31, 2016 Assets Commercial real estate property, net $ 277,866 $ 279,451 Debt and preferred equity investments, net 274,741 273,749 Other assets 18,005 18,922 Total assets $ 570,612 $ 572,122 Liabilities and members' equity Mortgages and other loans payable, net $ 137,307 $ 137,030 Other liabilities 20,973 22,185 Members' equity 412,332 412,907 Total liabilities and members' equity $ 570,612 $ 572,122 Company's investments in unconsolidated joint ventures $ 174,678 $ 174,127 The combined statements of operations for the unconsolidated joint ventures for the three months ended March 31, 2017 and 2016 , are as follows (in thousands): Three Months Ended March 31, 2017 2016 Total revenues $ 11,249 $ 6,937 Operating expenses 211 374 Real estate taxes 313 283 Interest expense, net of interest income 825 698 Amortization of deferred financing costs 277 277 Transaction related costs — — Depreciation and amortization 2,101 2,101 Total expenses $ 3,727 $ 3,733 Net income $ 7,522 $ 3,204 Company's equity in net income from unconsolidated joint ventures 4,255 2,457

Mortgages and Other Loans Pay29

Mortgages and Other Loans Payable (Tables)	3 Months Ended
	Mar. 31, 2017
Mortgage Note and Other Loans Payable
Schedule of the first mortgage note and other loans payable collateralized by the property, assignment of leases and investment	The first mortgages and other loans payable collateralized by the respective properties and assignment of leases or debt investments at March 31, 2017 and December 31, 2016 , respectively, were as follows (amounts in thousands): Property Maturity Date Interest Rate (1) March 31, 2017 December 31, 2016 Fixed Rate Debt: 919 Third Avenue (2) June 2023 5.12 % $ 500,000 $ 500,000 315 West 33rd Street February 2027 4.24 % 250,000 — Floating Rate Debt: Master Repurchase Agreement July 2018 3.28 % $ 184,642 $ 184,642 Total mortgages and other loans payable $ 934,642 $ 684,642 Deferred financing costs, net of amortization (14,040 ) (8,574 ) Total mortgages and other loans payable, net $ 920,602 $ 676,068 (1) Effective weighted average interest rate for the three months ended March 31, 2017 . (2) We own a 51.0% controlling interest in the joint venture that is the borrower on this loan.

Corporate Indebtedness (Tables)

Corporate Indebtedness (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Schedule of senior unsecured notes and other related disclosures by scheduled maturity date	The following table sets forth our senior unsecured notes and other related disclosures as of March 31, 2017 and December 31, 2016 , respectively, by scheduled maturity date (dollars in thousands): Issuance March 31, March 31, December 31, Coupon (1) Effective Term Maturity Date August 5, 2011 (2) $ 250,000 $ 249,898 $ 249,880 5.00 % 5.00 % 7 August 2018 March 16, 2010 (2) 250,000 250,000 250,000 7.75 % 7.75 % 10 March 2020 November 15, 2012 (2) 200,000 200,000 200,000 4.50 % 4.50 % 10 December 2022 December 17, 2015 (2) 100,000 100,000 100,000 4.27 % 4.27 % 10 December 2025 $ 800,000 $ 799,898 $ 799,880 Deferred financing costs, net (4,296 ) (4,620 ) $ 800,000 $ 795,602 $ 795,260 (1) Interest on the senior unsecured notes is payable semi-annually with principal and unpaid interest due on the scheduled maturity dates. (2) Issued by SL Green, the Operating Partnership and ROP, as co-obligors.
Schedule of Combined aggregate principal maturities of mortgage and other loans payable, 2012 credit facility and senior unsecured notes, including as-of-right extension options	Combined aggregate principal maturities of our mortgage and other loans payable, 2012 credit facility and senior unsecured notes as of March 31, 2017 , including as-of-right extension options and put options, were as follows (in thousands): Scheduled Principal Revolving Unsecured Term Loan Senior Unsecured Notes Total Remaining 2017 $ — $ — $ — $ — $ — $ — 2018 — 184,642 — — 250,000 434,642 2019 — — — 1,183,000 — 1,183,000 2020 — — — — 250,000 250,000 2021 — — — — — — Thereafter — 750,000 — — 300,000 1,050,000 $ — $ 934,642 $ — $ 1,183,000 $ 800,000 $ 2,917,642
Schedule of Consolidated Interest expense, excluding capitalized interest	Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended March 31, 2017 2016 Interest expense before capitalized interest $ 29,851 $ 32,314 Interest capitalized (380 ) (109 ) Interest income (4 ) (4 ) Interest expense, net $ 29,467 $ 32,201

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	The following table provides the carrying value and fair value of these financial instruments as of March 31, 2017 and December 31, 2016 (in thousands): March 31, 2017 December 31, 2016 Carrying Value (1) Fair Value Carrying Value (1) Fair Value Debt and preferred equity investments (2) $ 1,627,836 (3) $ 1,640,412 (3) Fixed rate debt $ 2,349,898 $ 2,438,513 $ 2,099,880 $ 2,183,042 Variable rate debt 567,642 578,410 567,642 580,083 $ 2,917,540 $ 3,016,923 $ 2,667,522 $ 2,763,125 (1) Amounts exclude net deferred financing costs. (2) Excludes investments with a book value of $174.7 million and $174.1 million as of March 31, 2017 and December 31, 2016 , respectively, which we accounted for under the equity method accounting as a result of meeting criteria of a real estate investment under the guidance for Acquisition, Development and Construction arrangements, and other investments with a book value of $119.4 million and $144.5 million as of March 31, 2017 and December 31, 2016 , respectively. (3) At March 31, 2017 , debt and preferred equity investments had an estimated fair value ranging between $1.6 billion and $1.8 billion . At December 31, 2016 , debt and preferred equity investments had an estimated fair value ranging between $1.6 billion and $1.8 billion .

Financial Instruments_ Deriva32

Financial Instruments: Derivatives and Hedging (Tables)	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of effect of derivative financial instruments on consolidated statements of income	The following table presents the effect of our derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the three months ended March 31, 2017 and 2016 , respectively (in thousands): Amount of Loss Recognized in Other Comprehensive Loss (Effective Portion) Location of Loss Reclassified from Accumulated Other Comprehensive Loss into Income Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Location of Gain Recognized in Income on Derivative Amount of Gain Recognized into Income (Ineffective Portion) Three Months Ended March 31, Three Months Ended March 31, Three Months Ended March 31, Derivative 2017 2016 2017 2016 2017 2016 Interest Rate Swap $ — $ (12 ) Interest expense $ 90 $ 232 Interest expense $ — $ 2

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum lease payments under capital leases and noncancellable operating leases	The following is a schedule of future minimum lease payments under non-cancellable operating leases with initial terms in excess of one year as of March 31, 2017 (in thousands): Non-cancellable operating leases Remaining 2017 $ 15,440 2018 20,586 2019 20,586 2020 20,586 2021 20,736 Thereafter 308,202 Total minimum lease payments $ 406,136

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Schedule of Selected results of operations and selected asset information	Selected consolidated results of operations for the three months ended March 31, 2017 and 2016 , and selected asset information as of March 31, 2017 and December 31, 2016 , regarding our operating segments are as follows (in thousands): Real Estate Segment Debt and Preferred Equity Segment Total Company Total revenues: Three months ended: March 31, 2017 $ 185,019 $ 47,336 $ 232,355 March 31, 2016 178,783 60,881 239,664 (Loss) income from continuing operations before equity in net gain on sale of interest from unconsolidated joint venture/real estate and depreciable real estate reserves: Three months ended: March 31, 2017 $ (29,259 ) $ 40,401 $ 11,142 March 31, 2016 18,460 53,740 72,200 Total assets As of: March 31, 2017 $ 6,692,595 $ 1,932,175 $ 8,624,770 December 31, 2016 6,786,479 1,968,134 8,754,613

Organization and Basis of Pre35

Organization and Basis of Presentation (Details) $ in Billions	3 Months Ended
	Mar. 31, 2017USD ($)ft²property
Real estate properties
Percentage of ownership in SL Green Operating Partnership owned by SL Green Realty Corp (as a percent)	95.67%
Number of Properties | property	42
Approximate Square Feet (sqft)	12,539,646
Weighted Average Occupancy (as a percent)	92.90%
Debt and preferred equity investments including investments held by unconsolidated joint ventures | $	$ 1.9
Debt and preferred equity investments and other financing receivables included in other balance sheet items | $	$ 0.3
Manhattan
Real estate properties
Number of Properties | property	23
Approximate Square Feet (sqft)	9,013,791
Weighted Average Occupancy (as a percent)	96.40%
Suburban
Real estate properties
Number of Properties | property	19
Approximate Square Feet (sqft)	3,303,000
Weighted Average Occupancy (as a percent)	83.30%
Office | Manhattan
Real estate properties
Number of Properties | property	16
Approximate Square Feet (sqft)	8,463,245
Weighted Average Occupancy (as a percent)	96.40%
Office | Suburban
Real estate properties
Number of Properties | property	18
Approximate Square Feet (sqft)	3,251,000
Weighted Average Occupancy (as a percent)	83.00%
Retail | 131-137 Spring Street
Real estate properties
Approximate Square Feet (sqft)	68,342
Number of unconsolidated joint venture properties | property	2
Retail | Manhattan
Real estate properties
Number of Properties | property	6
Approximate Square Feet (sqft)	374,016
Weighted Average Occupancy (as a percent)	95.80%
Retail | Suburban
Real estate properties
Number of Properties | property	1
Approximate Square Feet (sqft)	52,000
Weighted Average Occupancy (as a percent)	100.00%
Fee Interest | Manhattan
Real estate properties
Number of Properties | property	1
Approximate Square Feet (sqft)	176,530
Weighted Average Occupancy (as a percent)	100.00%
Commercial
Real estate properties
Number of Properties | property	42
Approximate Square Feet (sqft)	12,316,791
Weighted Average Occupancy (as a percent)	92.90%
Residential | Manhattan
Real estate properties
Number of Properties | property	0
Approximate Square Feet (sqft)	222,855
Weighted Average Occupancy (as a percent)	94.00%
Dual property type, retail portion
Real estate properties
Approximate Square Feet (sqft)	270,132
Dual property type, residential portion
Real estate properties
Approximate Square Feet (sqft)	222,855

Significant Accounting Polici36

Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Investment in Commercial Real Estate Properties
Commercial real estate properties	$ 5,928,994		$ 6,071,648
Mortgages and other loans payable, net	920,602		676,068
Depreciable real estate reserves	(56,265)	$ 0
Increase in rental revenue from amortization of acquired leases	4,200	$ 4,000
Identified intangible assets (included in other assets):
Gross amount	309,678		311,830
Accumulated amortization	(254,821)		(253,064)
Net1	54,857		58,766
Identified intangible liabilities (included in deferred revenue):
Gross amount	521,873		524,793
Accumulated amortization	(372,100)		(368,738)
Net1	149,773		156,055
Net Intangible Assets Transferred to Assets Held for Sale	100		0
Net Intangible Liabilities Transferred to Liabilities Related to Assets Held for Sale	$ 100		0
Above-market leases | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)	1 year
Above-market leases | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)	14 years
Below-market leases | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)	1 year
Below-market leases | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)	14 years
In-place leases | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)	1 year
In-place leases | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)	14 years
Building | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (years)	3 years
Building | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (years)	40 years
Variable Interest Entity, Primary Beneficiary
Investment in Commercial Real Estate Properties
Commercial real estate properties	$ 1,400,000		1,400,000
Mortgages and other loans payable, net	494,300		$ 494,100
520 White Plains Road and 680/750 Washington Boulevard [Member]
Investment in Commercial Real Estate Properties
Depreciable real estate reserves	$ 56,300

Significant Accounting Polici37

Significant Accounting Policies (Concentrations of Credit Risk/Reclassification)(Details) - Annualized cash rent - Customer concentration	3 Months Ended
	Mar. 31, 2017
Concentrations of Credit Risk
Maximum percentage of annualized cash rent for any one tenant not individually disclosed (more than)	5.00%
1185 Avenue of the Americas
Concentrations of Credit Risk
Percentage of concentration	13.60%
625 Madison Avenue
Concentrations of Credit Risk
Percentage of concentration	8.80%
Third Avenue, 919 [Member]
Concentrations of Credit Risk
Percentage of concentration	7.40%
750 Third Avenue
Concentrations of Credit Risk
Percentage of concentration	7.10%
810 Seventh Avenue
Concentrations of Credit Risk
Percentage of concentration	6.70%
1350 Avenue of the Americas
Concentrations of Credit Risk
Percentage of concentration	6.00%
555 W. 57th Street
Concentrations of Credit Risk
Percentage of concentration	6.00%
125 Park Avenue
Concentrations of Credit Risk
Percentage of concentration	6.00%

Property Disposition (Details)

Property Disposition (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
102 Greene Street
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Joint Venture Ownership Percentage Sold	90.00%
520 White Plains Road
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciable Real Estate Reserves, Effect on Earnings, Attributable to Parent	$ 14.2

Debt and Preferred Equity Inv39

Debt and Preferred Equity Investments (Details)	3 Months Ended
	Mar. 31, 2017USD ($)segment	Mar. 31, 2016USD ($)segment	Dec. 31, 2016USD ($)	Sep. 30, 2014USD ($)	Sep. 24, 2014USD ($)
Debt and preferred equity investments
Increase in debt and preferred equity investments	$ 403,900,000	$ 128,800,000
Repayments, participations and sales	$ 416,500,000	$ 420,200,000
Interest rate (as a percent)	9.42%
Debt Investments Held [Abstract]
Number of portfolio segments | segment	1	1
Financing Receivable, Recorded in Other Assets	$ 119,400,000		$ 144,500,000
Mezzanine Loan, June 2017
Debt Investments Held [Abstract]
Amount participated out	41,300,000
Mezzanine Loan, June 2024
Debt Investments Held [Abstract]
Amount participated out	12,000,000
Mezzanine Loan with an Initial Maturity Date of June 2017, 2 [Member]
Debt Investments Held [Abstract]
Amount participated out	14,500,000
Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Amount participated out	14,600,000
Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Amount participated out	14,100,000
Mortgage/Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Amount participated out	5,100,000
Debt Investments in Mortgage Loans [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	241,683,000
Senior Financing	5,386,263,000
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,579,930,000		1,592,537,000
Preferred Equity Investments in Mortgage Loans
Debt and preferred equity investments
Interest rate (as a percent)	8.36%
Debt Investments Held [Abstract]
Future Funding Obligations	$ 0
Senior Financing	132,065,000
Carrying Value, Net of Discounts and Deferred Origination Fees	47,906,000		47,875,000
Preferred Equity, March 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	73,448,000
Carrying Value, Net of Discounts and Deferred Origination Fees	9,986,000		9,982,000
Preferred Equity, November 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	58,617,000
Carrying Value, Net of Discounts and Deferred Origination Fees	37,920,000		37,893,000
Junior Mortgage Participation Acquired in September 2014
Debt Investments Held [Abstract]
Carrying Value, Net of Discounts and Deferred Origination Fees	0				$ 0
Fixed Rate Investments
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	2,314,991,000
Carrying Value, Net of Discounts and Deferred Origination Fees	364,345,000		360,359,000
Fixed Rate Investments | Mezzanine Loan, June 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	502,100,000
Carrying Value, Net of Discounts and Deferred Origination Fees	66,197,000		66,129,000
Fixed Rate Investments | Mortgage Loan, February 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	26,324,000		26,311,000
Loan acquired				$ 26,400,000
Discount on loan acquired				200,000
Fixed Rate Investments | Mortgage Loan, August 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	346,000		380,000
Fixed Rate Investments | Mezzanine Loan with an Initial Maturity Date of March 2020 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	1,160,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	197,358,000		0
Fixed Rate Investments | Mezzanine Loan, September 2021
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	15,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	3,500,000		3,500,000
Fixed Rate Investments | Mezzanine Loan, November 2023
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	87,891,000
Carrying Value, Net of Discounts and Deferred Origination Fees	12,694,000		12,692,000
Fixed Rate Investments | Mezzanine Loan, June 2024
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	115,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	12,926,000		12,925,000
Fixed Rate Investments | Mezzanine Loan, January 2025
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	95,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	30,000,000		30,000,000
Fixed Rate Investments | Mezzanine Loan with an Initial Maturity Date of November 2026 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	340,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	15,000,000		15,000,000
Fixed Rate Investments | Junior Mortgage Participation or Mezzanine Loan repaid in March 2017 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	0		193,422,000
Fixed Rate Investments | Junior Mortgage Participation, Related To Mortgage Loan, February 2019
Debt Investments Held [Abstract]
Loan acquired				5,700,000
Discount on loan acquired				$ 5,700,000
Floating Rate Investments
Debt Investments Held [Abstract]
Future Funding Obligations	241,683,000
Senior Financing	3,071,272,000
Carrying Value, Net of Discounts and Deferred Origination Fees	1,215,585,000		1,232,178,000
Floating Rate Investments | Mezzanine Loan, June 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	32,929,000		32,847,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity Date of June 2017, 2 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	40,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	15,446,000		15,369,000
Floating Rate Investments | Mortgage/Mezzanine Loan with an Initial Maturity Date of July 2017 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	22,978,000		22,959,000
Floating Rate Investments | Mortgage/Mezzanine Loan, September 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	16,975,000		16,960,000
Floating Rate Investments | Mortgage/Mezzanine Loan, October 2017
Debt Investments Held [Abstract]
Future Funding Obligations	2,302,000
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	21,630,000		20,423,000
Floating Rate Investments | Mezzanine Loan, November 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	60,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	14,970,000		14,957,000
Floating Rate Investments | Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	85,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	15,206,000		15,141,000
Floating Rate Investments | Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	65,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	14,714,000		14,656,000
Floating Rate Investments | Mortgage/Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Future Funding Obligations	795,000
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	15,078,000		15,051,000
Floating Rate Investments | Mortgage/Mezzanine Loan with an Initial Maturity Date of January 2018 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	125,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	29,902,000		29,998,000
Floating Rate Investments | Mezzanine Loan, April 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	40,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	19,930,000		19,913,000
Floating Rate Investments | Junior Participation Loan, April 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	175,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	34,873,000		34,844,000
Floating Rate Investments | Mortgage/Mezzanine Loan, with an Initial Maturity Date of August 2018 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	523,000
Senior Financing	20,523,000
Carrying Value, Net of Discounts and Deferred Origination Fees	10,880,000		10,863,000
Floating Rate Investments | Mortgage Loan, August 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	19,864,000		19,840,000
Floating Rate Investments | Mezzanine Loan, August 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	65,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	14,898,000		14,880,000
Floating Rate Investments | Mezzanine Loan, September 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	37,500,000
Carrying Value, Net of Discounts and Deferred Origination Fees	14,698,000		14,648,000
Floating Rate Investments | Mezzanine Loan, October 2018
Debt Investments Held [Abstract]
Future Funding Obligations	2,325,000
Senior Financing	45,025,000
Carrying Value, Net of Discounts and Deferred Origination Fees	34,593,000		34,502,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity Date of November 2018 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	335,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	74,543,000		74,476,000
Floating Rate Investments | Mezzanine Loan, December 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	33,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	26,868,000		26,850,000
Floating Rate Investments | Mezzanine Loan, December 2018
Debt Investments Held [Abstract]
Future Funding Obligations	2,005,000
Senior Financing	169,152,000
Carrying Value, Net of Discounts and Deferred Origination Fees	57,496,000		56,114,000
Floating Rate Investments | Mezzanine Loan, December 2018
Debt Investments Held [Abstract]
Future Funding Obligations	14,191,000
Senior Financing	265,704,000
Carrying Value, Net of Discounts and Deferred Origination Fees	64,870,000		63,137,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity Date of December 2018, 4 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	11,177,000
Senior Financing	210,770,000
Carrying Value, Net of Discounts and Deferred Origination Fees	68,136,000		64,505,000
Floating Rate Investments | Mezzanine Loan, January 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	45,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	12,120,000		12,104,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity Date of January 2019, 2 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	42,548,000
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	171,352,000		0
Floating Rate Investments | Mezzanine Loan with an Initial Maturity of January 2019, 3 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	6,383,000
Senior Financing	16,383,000
Carrying Value, Net of Discounts and Deferred Origination Fees	5,434,000		5,410,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity of March 2019 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	38,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	21,903,000		21,891,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity Date of April 2019 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	265,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	24,736,000		24,707,000
Floating Rate Investments | Mortgage/Jr Mortgage Participate Loan, Maturity Date of August 2019 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	32,721,000
Senior Financing	185,649,000
Carrying Value, Net of Discounts and Deferred Origination Fees	66,484,000		65,554,000
Floating Rate Investments | Mezzanine Loan, Maturity of September 2019 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	2,500,000
Senior Financing	187,500,000
Carrying Value, Net of Discounts and Deferred Origination Fees	37,337,000		37,322,000
Floating Rate Investments | Mortgage/Mezzanine Loan with an Initial Maturity of September 2019 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	75,310,000
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	119,422,000		111,819,000
Floating Rate Investments | Mortgage/Mezzanine Loan with an Initial Maturity of January 2020 [Member] [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	35,630,000
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	33,714,000		33,682,000
Floating Rate Investments | Mezzanine Loan with an Initial Maturity of January 2020 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	13,273,000
Senior Financing	502,066,000
Carrying Value, Net of Discounts and Deferred Origination Fees	65,993,000		125,911,000
Transfer of Financial Assets Accounted for as Sales, Cash Proceeds Received for Assets Derecognized, Amount	66,100,000
Floating Rate Investments | Jr Mortgage Participation/Mezzanine Loan with an Initial Maturity of July 2021 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	60,000,000
Carrying Value, Net of Discounts and Deferred Origination Fees	15,613,000		15,606,000
Floating Rate Investments | Mortgage/Mezzanine Loan repaid in January 2017 [Member]
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 0		$ 145,239,000

Investments in Unconsolidated40

Investments in Unconsolidated Joint Ventures (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)ft²note	Dec. 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Approximate Square Feet (sqft) | ft²	12,539,646
Acquisition, development and construction arrangements, carrying value	$ 124,965	$ 124,542
Participating Financing Due March 2018 [Member]
Schedule of Equity Method Investments [Line Items]
Acquisition, development and construction arrangements, carrying value	100,000	100,000
Mezzanine Loan Due July 2036
Schedule of Equity Method Investments [Line Items]
Acquisition, development and construction arrangements, carrying value	$ 24,965	$ 24,542
131-137 Spring Street
Schedule of Equity Method Investments [Line Items]
Ownership Interest (as a percent)	20.00%
Economic Interest (as a percent)	20.00%
Approximate Square Feet (sqft) | ft²	68,342
Acquisition Price	$ 277,750
76 11th Avenue
Schedule of Equity Method Investments [Line Items]
Ownership Interest (as a percent)	33.33%
Economic Interest (as a percent)	35.09%
Approximate Square Feet (sqft) | ft²	764,000
Acquisition Price	$ 138,240
Exit fee, percentage owned	50.00%
76 11th Avenue | Joint Venture
Schedule of Equity Method Investments [Line Items]
Exit fee, percentage owned	38.00%
Partners' Interest | 76 11th Avenue | Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of mezzanine notes secured | note	2
Exit fee, percentage owned	25.00%
Extension Fee, Percentage Owned	31.00%

Investments in Unconsolidated41

Investments in Unconsolidated Joint Ventures (Mortgages and Other Loans Payable) (Details) - Joint Venture - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Total joint venture mortgages and other loans payable	$ 141,000	$ 141,000
Deferred financing costs, net	(3,693)	(3,970)
Total joint venture mortgages and other loans payable, net	137,307	137,030
131-137 Spring Street
Schedule of Equity Method Investments [Line Items]
Floating rate debt	$ 141,000	$ 141,000
Weighted Average | 131-137 Spring Street
Schedule of Equity Method Investments [Line Items]
Interest rate (as a percent)	2.33%

Investments in Unconsolidated42

Investments in Unconsolidated Joint Ventures (Schedules of Combined Financial Statements for the Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Assets
Commercial real estate property, net	$ 5,928,994		$ 6,071,648
Debt and preferred equity investments, net	1,627,836		1,640,412
Other assets	343,468		374,091
Liabilities and members' equity
Mortgages and other loans payable, net	920,602		676,068
Other liabilities	119,086		160,982
Company's investments in unconsolidated joint ventures	174,678		174,127
Combined statements of income for the unconsolidated joint ventures
Operating expenses	41,725	$ 41,961
Real estate taxes	38,796	37,224
Amortization of deferred financing costs	2,087	2,140
Depreciation and amortization	51,784	50,798
Total expenses	169,206	169,921
Company's equity in net income from unconsolidated joint ventures	4,255	2,457
Joint Venture
Assets
Commercial real estate property, net	277,866		279,451
Debt and preferred equity investments, net	274,741		273,749
Other assets	18,005		18,922
Total assets	570,612		572,122
Liabilities and members' equity
Mortgages and other loans payable, net	137,307		137,030
Other liabilities	20,973		22,185
Members' equity	412,332		412,907
Total liabilities and members' equity	570,612		$ 572,122
Combined statements of income for the unconsolidated joint ventures
Total revenues	11,249	6,937
Operating expenses	211	374
Real estate taxes	313	283
Interest expense, net of interest income	825	698
Amortization of deferred financing costs	277	277
Transaction related costs	0	0
Depreciation and amortization	2,101	2,101
Total expenses	3,727	3,733
Net income	7,522	3,204
Company's equity in net income from unconsolidated joint ventures	$ 4,255	$ 2,457

Mortgages and Other Loans Pay43

Mortgages and Other Loans Payable (Details) - USD ($)	Dec. 06, 2015	Mar. 31, 2017	Dec. 31, 2016
Mortgage note and other loan payable
Total mortgages and other loans payable		$ 934,642,000	$ 684,642,000
Deferred financing costs, net of amortization		(14,040,000)	(8,574,000)
Total mortgages and other loans payable, net		920,602,000	676,068,000
Gross book value of the property and investment collateralizing the mortgage note and other loan payable		2,300,000,000	1,700,000,000
Master Repurchase Agreement
Mortgage note and other loan payable
Floating rate debt		184,642,000	184,642,000
Maximum borrowing capacity		$ 300
Basis point fee (as a percent)	0.25%
Threshold amount for basis point fee to be applicable (less than)	$ 150,000,000
Master Repurchase Agreement | Weighted Average
Mortgage note and other loan payable
Interest rate (as a percent)		3.28%
Master Repurchase Agreement | Minimum | LIBOR
Mortgage note and other loan payable
Credit facility, interest rate (as a percent)		2.25%
Master Repurchase Agreement | Maximum | LIBOR
Mortgage note and other loan payable
Credit facility, interest rate (as a percent)		4.00%
Third Avenue, 919 [Member]
Mortgage note and other loan payable
Fixed rate debt		$ 500,000,000	500,000,000
Controlling interest in the joint venture (as a percent)		51.00%
Third Avenue, 919 [Member] | Weighted Average
Mortgage note and other loan payable
Interest rate (as a percent)		5.12%
315 West 33rd Street
Mortgage note and other loan payable
Fixed rate debt		$ 250,000,000	$ 0
315 West 33rd Street | Weighted Average
Mortgage note and other loan payable
Interest rate (as a percent)		4.24%

Corporate Indebtedness (Details

Corporate Indebtedness (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Corporate Indebtedness
Carrying value	$ 2,917,642,000
Debt disclosures by scheduled maturity date
Accreted Balance	1,179,861,000		$ 1,179,521,000
Scheduled amortization and principal repayments
Remaining 2,017	0
2,018	434,642,000
2,019	1,183,000,000
2,020	250,000,000
2,021	0
Thereafter	1,050,000,000
Total amortization of debt and principal repayments	2,917,642,000
Interest expense
Interest expense	29,851,000	$ 32,314,000
Interest capitalized	(380,000)	(109,000)
Interest income	(4,000)	(4,000)
Interest expense, net	29,467,000	$ 32,201,000
Senior Unsecured Notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	800,000,000
Accreted Balance	799,898,000		799,880,000
Deferred financing costs, net	(4,296,000)		(4,620,000)
Total	795,602,000		795,260,000
Revolving credit facility
Corporate Indebtedness
Maximum borrowing capacity	1,600,000,000
Maximum borrowing capacity, optional expansion	$ 3,000,000,000
Facility fee on total commitments, payable quarterly in arrears (as a percent)	0.25%
Revolving credit facility, net	$ 0
Carrying value	$ 0
Debt disclosures by scheduled maturity date
Effective Rate (as a percent)	2.03%
Scheduled amortization and principal repayments
Remaining 2,017	$ 0
2,018	0
2,019	0
2,020	0
2,021	0
Thereafter	0
Total amortization of debt and principal repayments	$ 0
Revolving credit facility | Minimum
Corporate Indebtedness
Facility fee on total commitments, payable quarterly in arrears (as a percent)	0.125%
Revolving credit facility | Maximum
Corporate Indebtedness
Facility fee on total commitments, payable quarterly in arrears (as a percent)	0.30%
Revolving credit facility | LIBOR
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.25%
Revolving credit facility | LIBOR | Minimum
Corporate Indebtedness
Interest rate added to base rate (as a percent)	0.875%
Revolving credit facility | LIBOR | Maximum
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.55%
Term loan
Corporate Indebtedness
Maximum borrowing capacity	$ 1,183,000,000
Carrying value	$ 1,183,000,000
Debt disclosures by scheduled maturity date
Effective Rate (as a percent)	2.18%
Scheduled amortization and principal repayments
Remaining 2,017	$ 0
2,018	0
2,019	1,183,000,000
2,020	0
2,021	0
Thereafter	0
Total amortization of debt and principal repayments	1,183,000,000
Term loan | Line of Credit
Corporate Indebtedness
Carrying value	1,200,000,000		1,200,000,000
Scheduled amortization and principal repayments
Total amortization of debt and principal repayments	$ 1,200,000,000		1,200,000,000
Term loan | LIBOR
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.40%
Term loan | LIBOR | Minimum
Corporate Indebtedness
Interest rate added to base rate (as a percent)	0.95%
Term loan | LIBOR | Maximum
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.90%
Credit Facility 2012
Corporate Indebtedness
Letters of credit	$ 84,800,000
Ability to borrow under line of credit facility	1,500,000,000
Credit Facility 2012 | Line of Credit
Corporate Indebtedness
Carrying value	(5,600,000)		(6,300,000)
Scheduled amortization and principal repayments
Total amortization of debt and principal repayments	(5,600,000)		(6,300,000)
5.00% senior unsecured notes maturing on August 15, 2018 | Senior Unsecured Notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	250,000,000
Accreted Balance	$ 249,898,000		249,880,000
Coupon Rate (as a percent)	5.00%
Effective Rate (as a percent)	5.00%
Term (in Years)	7 years
7.75% senior unsecured notes maturing on March 15, 2020 | Senior Unsecured Notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 250,000,000
Accreted Balance	$ 250,000,000		250,000,000
Coupon Rate (as a percent)	7.75%
Effective Rate (as a percent)	7.75%
Term (in Years)	10 years
4.50% senior unsecured notes maturing on December 01, 2022 | Senior Unsecured Notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 200,000,000
Accreted Balance	$ 200,000,000		200,000,000
Coupon Rate (as a percent)	4.50%
Effective Rate (as a percent)	4.50%
Term (in Years)	10 years
4.27% senior unsecured notes maturing December 17, 2025 | Senior Unsecured Notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 100,000,000
Accreted Balance	$ 100,000,000		$ 100,000,000
Coupon Rate (as a percent)	4.27%
Effective Rate (as a percent)	4.27%
Term (in Years)	10 years
Exchangeable Senior Notes Due 2017 | Senior Unsecured Notes
Debt disclosures by scheduled maturity date
Coupon Rate (as a percent)	3.00%
Mortgage and Other Loans Payable
Scheduled Amortization
Remaining 2,017	$ 0
2,018	0
2,019	0
2,020	0
2,021	0
Thereafter	0
Total amortization of debt	0
Principal Repayments
Remaining 2,017	0
2,018	184,642,000
2,019	0
2,020	0
2,021	0
Thereafter	750,000,000
Total principal repayments	934,642,000
Senior Unsecured Notes
Corporate Indebtedness
Carrying value	800,000,000
Scheduled amortization and principal repayments
Remaining 2,017	0
2,018	250,000,000
2,019	0
2,020	250,000,000
2,021	0
Thereafter	300,000,000
Total amortization of debt and principal repayments	$ 800,000,000

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Affiliate
Related Party Transactions
Profit participation received by related party	$ 0.8	$ 0.8
Alliance Building Services
Related Party Transactions
Payments made for services	2	1.7
SL Green
Related Party Transactions
Allocation of salary and other operating costs from related party	3.2	2.6
Insurance expense incurred	$ 1.4	$ 1.6

Preferred Units (Details)

Preferred Units (Details)	3 Months Ended
	Mar. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)	Aug. 31, 2015shares	Jul. 22, 2015USD ($)
Class of Stock [Line Items]
Number of company common stock issued on conversion of Series B preferred units	6.71348
Series A Preferred Units
Class of Stock [Line Items]
Fair value of embedded derivative | $	$ 0	$ 0		$ 0
Partnership Interest | Series A Preferred Units
Class of Stock [Line Items]
Number of units authorized (in shares) | shares	109,161
Dividend rate, preferred units (as a percent)	3.50%
Liquidation preference of preferred units (in usd per share) | $ / shares	$ 1,000
Number of units issued (in shares) | shares			109,161
Annual dividends on preferred units (in usd per share) | $ / shares	$ 35

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value of Financial Instruments
Debt and preferred equity investments, net	$ 1,627,836	$ 1,640,412
Company's investments in unconsolidated joint ventures	174,678	174,127
Financing Receivable, Recorded in Other Assets	119,400	144,500
Carrying Value (1)
Fair Value of Financial Instruments
Debt and preferred equity investments, net	1,627,836	1,640,412
Fair Value
Fair Value of Financial Instruments
Estimated fair value of debt and preferred equity investments, low end of range	1,600,000	1,600,000
Estimated fair value of debt and preferred equity investments, high end of range	1,800,000	1,800,000
Level 3 | Carrying Value (1)
Fair Value of Financial Instruments
Fixed rate debt	2,349,898	2,099,880
Variable rate debt	567,642	567,642
Total	2,917,540	2,667,522
Level 3 | Fair Value
Fair Value of Financial Instruments
Fixed rate debt	2,438,513	2,183,042
Variable rate debt	578,410	580,083
Total	$ 3,016,923	$ 2,763,125

Financial Instruments_ Deriva48

Financial Instruments: Derivatives and Hedging (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivative [Line Items]
Deferred net losses from terminated hedges	$ 1,500		$ 1,600
Estimated current balance held in accumulated other comprehensive loss to be reclassified into earnings within the next 12 months	400
Interest Rate Swap
Derivative [Line Items]
Amount of Gain Recognized in Other Comprehensive Loss (Effective Portion)	0	$ (12)
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	90	232
Amount of Gain Recognized into Income (Ineffective Portion)	$ 0	$ 2

Commitments and Contingencies49

Commitments and Contingencies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Minimum initial term of noncancellable operating leases (in years)	1 year
Non-cancellable operating leases
Remaining 2,017	$ 15,440
2,018	20,586
2,019	20,586
2,020	20,586
2,021	20,736
Thereafter	308,202
Total minimum lease payments	$ 406,136

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)segment	Mar. 31, 2016USD ($)	Dec. 31, 2016USD ($)
Segment information
Number of reportable segments | segment	2
Total revenues	$ 232,355	$ 239,664
Income (Loss) from Continuing Operations before Realized Gain (Loss) on Disposal of Equity Method Investment	11,142	72,200
Total assets	8,624,770		$ 8,754,613
Marketing, general and administrative	112	184
Real Estate Segment
Segment information
Total revenues	185,019	178,783
Income from continuing operations before loss on sale of real estate	(29,259)	18,460
Total assets	6,692,595		6,786,479
Debt and Preferred Equity Segment
Segment information
Total revenues	47,336	60,881
Income from continuing operations before loss on sale of real estate	40,401	$ 53,740
Total assets	$ 1,932,175		$ 1,968,134