Empire State Realty OP (FISK) 10-Q 31 Oct 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 24, 2019
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-36106
Entity Registrant Name	EMPIRE STATE REALTY OP, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-4685158
Entity Address, Address Line One	111 West 33rd Street
Entity Address, Address Line Two	12th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10120
City Area Code	212
Local Phone Number	687-8700
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001553079
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Series ES operating partnership units
Title of 12(b) Security	Series ES operating partnership units
Trading Symbol	ESBA
Security Exchange Name	NYSEArca
Entity Common Stock, Shares Outstanding		27,916,614
Series 60 operating partnership units
Title of 12(b) Security	Series 60 operating partnership units
Trading Symbol	OGCP
Security Exchange Name	NYSEArca
Entity Common Stock, Shares Outstanding		7,505,315
Series 250 operating partnership units
Title of 12(b) Security	Series 250 operating partnership units
Trading Symbol	FISK
Security Exchange Name	NYSEArca
Entity Common Stock, Shares Outstanding		3,766,134

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Commercial real estate properties, at cost:
Land	$ 201,196	$ 201,196
Development costs	7,989	7,987
Building and improvements	2,830,353	2,675,303
Commercial real estate properties, at cost	3,039,538	2,884,486
Less: accumulated depreciation	(829,495)	(747,304)
Commercial real estate properties, net	2,210,043	2,137,182
Cash and cash equivalents	293,710	204,981
Restricted cash	36,609	65,832
Short-term investments	0	400,000
Tenant and other receivables, net of allowance of $488 as of December 31, 2018	29,287	29,437
Deferred rent receivables, net of allowance of $19 as of December 31, 2018	214,685	200,903
Prepaid expenses and other assets	41,927	64,345
Deferred costs, net	223,698	241,223
Acquired below-market ground leases, net	354,524	360,398
Right of use assets	29,355
Goodwill	491,479	491,479
Total assets	3,925,317	4,195,780
Liabilities:
Mortgage notes payable, net	606,313	608,567
Senior unsecured notes, net	798,347	1,046,219
Unsecured term loan facility, net	264,517	264,147
Unsecured revolving credit facility	0	0
Accounts payable and accrued expenses	143,201	130,676
Acquired below-market leases, net	42,655	52,450
Ground lease liabilities	29,355
Deferred revenue and other liabilities	68,742	44,810
Tenants’ security deposits	31,841	57,802
Total liabilities	1,984,971	2,204,671
Commitments and contingencies
Capital:
Private perpetual preferred units, $16.62 per unit liquidation preference, 1,560,360 issued and outstanding in 2019 and 2018	8,004	8,004
Total capital	1,940,346	1,991,109
Total liabilities and capital	3,925,317	4,195,780
Series PR Operating Partnership Units
Capital:
ESRT partner's capital (3,042,566 and 3,033,261 general partner operating partnership units and 177,106,987 and 171,877,365 limited partner operating partnership units outstanding in 2019 and 2018, respectively)	1,222,019	1,238,482
Limited partner operating partnership units	700,479	725,108
Series ES operating partnership units
Capital:
Limited partner operating partnership units	7,454	14,399
Series 60 operating partnership units
Capital:
Limited partner operating partnership units	1,579	3,385
Series 250 operating partnership units
Capital:
Limited partner operating partnership units	$ 811	$ 1,731

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets
Tenant and other receivables allowance		$ 488
Deferred rent receivables allowance		$ 19
Capital
Private perpetual preferred units, liquidation preference (in USD per share)	$ 16.62	$ 16.62
Private perpetual preferred units, issued (in shares)	1,560,360	1,560,360
Private perpetual preferred units, outstanding (in shares)	1,560,360	1,560,360
Series PR Operating Partnership Units
Capital
Limited partner operating partnership units, outstanding (in shares)	84,561,214	86,202,638
Series ES operating partnership units
Capital
Limited partner operating partnership units, outstanding (in shares)	28,159,590	30,129,556
Series 60 operating partnership units
Capital
Limited partner operating partnership units, outstanding (in shares)	7,544,485	8,019,509
Series 250 operating partnership units
Capital
Limited partner operating partnership units, outstanding (in shares)	3,841,730	4,063,737
ESRT | Series PR Operating Partnership Units
Capital
General partner operating partnership units, outstanding (in shares)	3,042,566	3,033,261
Limited partner operating partnership units, outstanding (in shares)	177,106,987	171,877,365

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Rental revenue	$ 150,225		$ 434,713
Rental revenue		$ 123,621		$ 369,970
Tenant expense reimbursement	0	18,627	0	52,626
Observatory revenue	37,575	40,241	91,039	96,691
Lease termination fees	2,361	1,185	3,112	2,164
Third-party management and other fees	304	312	955	1,151
Other revenue and fees	2,408	2,416	6,591	9,600
Total revenues	192,873	186,402	536,410	532,202
Operating expenses:
Property operating expenses	47,894	42,772	131,076	126,375
Ground rent expenses	2,331	2,331	6,994	6,994
General and administrative expenses	14,421	13,148	44,445	39,001
Observatory expenses	9,089	8,854	25,024	23,868
Real estate taxes	29,599	28,284	86,098	81,771
Depreciation and amortization	44,260	42,475	135,179	121,826
Total operating expenses	147,594	137,864	428,816	399,835
Total operating income	45,279	48,538	107,594	132,367
Other income (expense):
Interest income	2,269	3,485	9,907	7,209
Interest expense	(19,426)	(20,658)	(60,712)	(58,774)
Income before income taxes	28,122	31,365	56,789	80,802
Income tax expense	(1,338)	(2,135)	(1,219)	(3,330)
Net income	26,784	29,230	55,570	77,472
Private perpetual preferred unit distributions	(234)	(234)	(702)	(702)
Net income attributable to common unitholders	$ 26,550	$ 28,996	$ 54,868	$ 76,770
Total weighted average units:
Basic (in units)	298,151	297,478	298,117	297,180
Diluted (in units)	298,151	297,478	298,117	297,181
Earnings per unit attributable to common unitholders:
Basic (in USD per unit)	$ 0.09	$ 0.10	$ 0.18	$ 0.26
Diluted (in USD per unit)	0.09	0.10	0.18	0.26
Dividends per unit (in USD per unit)	$ 0.105	$ 0.105	$ 0.315	$ 0.315

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 26,784	$ 29,230	$ 55,570	$ 77,472
Other comprehensive income (loss):
Unrealized gain (loss) on valuation of interest rate swap agreements	(6,256)	3,884	(25,992)	9,827
Less: amount reclassified into interest expense	319	427	637	1,562
Other comprehensive income (loss)	(5,937)	4,311	(25,355)	11,389
Comprehensive income (loss)	$ 20,847	$ 33,541	$ 30,215	$ 88,861

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Capital (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	$ 1,948,032	$ 1,983,141	$ 1,991,109	$ 1,977,737
Issuance of OP units, net of costs	0	0	0	4,749
Conversion of operating partnership units to ESRT Partner's Capital	0	0	0	0
Equity compensation	3,647	4,853	15,392	14,064
Distributions	(32,180)	(32,084)	(96,370)	(95,960)
Net income	26,784	29,230	55,570	77,472
Other comprehensive income (loss)	(5,937)	4,311	(25,355)	11,389
Ending balance	$ 1,940,346	$ 1,989,451	$ 1,940,346	$ 1,989,451
General Partner | Series PR Operating Partnership Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	178,021	167,704	174,912	161,477
Beginning balance	$ 1,215,647	$ 1,194,533	$ 1,238,482	$ 1,168,282
Issuance of OP units, net of costs (in units)	0	0	0	284
Issuance of OP units, net of costs	$ 0	$ 0	$ 0	$ 4,749
Conversion of operating partnership units to ESRT Partner's Capital (in units)	2,130	1,517	5,185	7,436
Conversion of operating partnership units to ESRT Partner's Capital	$ 12,796	$ 5,815	$ 21,654	$ 31,660
Equity compensation (in units)	(1)		53	24
Equity compensation	$ 191	153	$ 421	$ 269
Distributions	(18,907)	(17,727)	(56,098)	(52,519)
Net income	15,882	16,342	32,646	42,761
Other comprehensive income (loss)	$ (3,590)	$ 2,430	$ (15,086)	$ 6,344
Ending balance (in units)	180,150	169,221	180,150	169,221
Ending balance	$ 1,222,019	$ 1,201,546	$ 1,222,019	$ 1,201,546
Limited Partners | Series PR Operating Partnership Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	86,749	91,447	86,202	91,760
Beginning balance	$ 713,039	$ 759,895	$ 725,108	$ 778,279
Conversion of operating partnership units to ESRT Partner's Capital (in units)	(1,554)	(647)	(2,517)	(3,576)
Conversion of operating partnership units to ESRT Partner's Capital	$ (12,672)	$ (5,396)	$ (20,655)	$ (29,835)
Equity compensation (in units)	(634)		876	2,616
Equity compensation	$ 3,456	4,700	$ 14,971	$ 13,795
Distributions	(8,880)	(9,558)	(26,884)	(28,725)
Net income	7,114	8,294	14,760	22,340
Other comprehensive income (loss)	$ (1,578)	$ 1,233	$ (6,821)	$ 3,314
Ending balance (in units)	84,561	90,800	84,561	90,800
Ending balance	$ 700,479	$ 759,168	$ 700,479	$ 759,168
Limited Partners | Series ES Operating Partnership Units Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	28,518	31,407	30,129	33,774
Beginning balance	$ 8,508	$ 15,238	$ 14,399	$ 17,132
Conversion of operating partnership units to ESRT Partner's Capital (in units)	(358)	(497)	(1,969)	(2,864)
Conversion of operating partnership units to ESRT Partner's Capital	$ (85)	$ (253)	$ (788)	$ (1,394)
Distributions	(2,960)	(3,252)	(9,020)	(9,984)
Net income	2,547	3,084	5,322	8,291
Other comprehensive income (loss)	$ (556)	$ 458	$ (2,459)	$ 1,230
Ending balance (in units)	28,160	30,910	28,160	30,910
Ending balance	$ 7,454	$ 15,275	$ 7,454	$ 15,275
Limited Partners | Series 60 Operating Partnership Units Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	7,686	8,545	8,020	8,988
Beginning balance	$ 1,871	$ 3,580	$ 3,385	$ 3,992
Conversion of operating partnership units to ESRT Partner's Capital (in units)	(142)	(301)	(476)	(744)
Conversion of operating partnership units to ESRT Partner's Capital	$ (25)	$ (133)	$ (143)	$ (318)
Distributions	(794)	(872)	(2,431)	(2,689)
Net income	662	841	1,427	2,226
Other comprehensive income (loss)	$ (135)	$ 125	$ (659)	$ 330
Ending balance (in units)	7,544	8,244	7,544	8,244
Ending balance	$ 1,579	$ 3,541	$ 1,579	$ 3,541
Limited Partners | Series 250 Operating Partnership Units Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	3,917	4,230	4,064	4,410
Beginning balance	$ 963	$ 1,891	$ 1,731	$ 2,048
Conversion of operating partnership units to ESRT Partner's Capital (in units)	(75)	(72)	(222)	(252)
Conversion of operating partnership units to ESRT Partner's Capital	$ (14)	$ (33)	$ (68)	$ (113)
Distributions	(405)	(441)	(1,235)	(1,341)
Net income	345	435	713	1,152
Other comprehensive income (loss)	$ (78)	$ 65	$ (330)	$ 171
Ending balance (in units)	3,842	4,158	3,842	4,158
Ending balance	$ 811	$ 1,917	$ 811	$ 1,917
Private Perpetual Preferred Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	1,560	1,560	1,560	1,560
Beginning balance	$ 8,004	$ 8,004	$ 8,004	$ 8,004
Distributions	(234)	(234)	(702)	(702)
Net income	$ 234	$ 234	$ 702	$ 702
Ending balance (in units)	1,560	1,560	1,560	1,560
Ending balance	$ 8,004	$ 8,004	$ 8,004	$ 8,004

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows From Operating Activities
Net income	$ 55,570	$ 77,472
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	135,179	121,826
Amortization of non-cash items within interest expense	5,400	5,142
Amortization of acquired above- and below-market leases, net	(5,780)	(4,387)
Amortization of acquired below-market ground leases	5,873	5,873
Straight-lining of rental revenue	(13,781)	(16,662)
Equity based compensation	15,392	14,064
Increase (decrease) in cash flows due to changes in operating assets and liabilities:
Security deposits	(25,961)	(4,566)
Tenant and other receivables	149	(3,176)
Deferred leasing costs	(14,513)	(18,578)
Prepaid expenses and other assets	19,883	20,308
Accounts payable and accrued expenses	(2,970)	(1,181)
Deferred revenue and other liabilities	23,932	(8,732)
Net cash provided by operating activities	198,373	187,403
Cash Flows From Investing Activities
Short-term investments	400,000	(400,000)
Development costs	(2)	(1)
Additions to building and improvements	(189,666)	(169,622)
Net cash provided by (used in) investing activities	210,332	(569,623)
Cash Flows From Financing Activities
Proceeds from mortgage notes payable	0	160,000
Repayment of mortgage notes payable	(2,829)	(265,688)
Proceeds from unsecured senior notes	0	335,000
Repayment of unsecured senior notes	(250,000)	0
Proceeds from the sale of common stock	0	4,749
Deferred financing costs	0	(1,977)
Distributions	(96,370)	(95,960)
Net cash (used in) provided by financing activities	(349,199)	136,124
Net increase (decrease) in cash and cash equivalents and restricted cash	59,506	(246,096)
Cash and cash equivalents and restricted cash—beginning of period	270,813	530,197
Cash and cash equivalents and restricted cash—end of period	330,319	284,101
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	204,981	464,344
Restricted cash at beginning of period	65,832	65,853
Cash and cash equivalents at end of period	293,710	229,745
Restricted cash at end of period	36,609	54,356
Supplemental disclosures of cash flow information:
Cash paid for interest	59,173	56,597
Cash paid for income taxes	1,589	3,690
Non-cash investing and financing activities:
Building and improvements included in accounts payable and accrued expenses	77,142	92,506
Write-off of fully depreciated assets	26,516	32,059
Derivative instruments at fair values included in prepaid expenses and other assets	0	9,944
Derivative instruments at fair values included in accounts payable and accrued expenses	28,850	0
Conversion of limited partners' operating partnership units to ESRT partner's capital	21,654	$ 31,660
Right of use assets	29,452
Ground lease liabilities	$ 29,452

Description of Business and Org

Description of Business and Organization	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Organization	Description of Business and Organization As used in these condensed consolidated financial statements, unless the context otherwise requires, “we,” “us,” "our," and the "company,” mean Empire State Realty OP, L.P. and its consolidated subsidiaries. Empire State Realty OP, L.P. (the "Operating Partnership") is the entity through which Empire State Realty Trust, Inc. (“ESRT”), a self-administered and self-managed real estate investment trust ("REIT"), conducts all of its business and owns (either directly or through subsidiaries) substantially all of its assets. We own, manage, operate, acquire and reposition office and retail properties in Manhattan and the greater New York metropolitan area. As of September 30, 2019 , our total portfolio contained 10.1 million rentable square feet of office and retail space. We owned 14 office properties (including three long-term ground leasehold interests) encompassing approximately 9.4 million rentable square feet of office space. Nine of these properties are located in the midtown Manhattan market and aggregate approximately 7.6 million rentable square feet of office space, including the Empire State Building. Our Manhattan office properties also contain an aggregate of 511,755 rentable square feet of retail space on their ground floor and/or contiguous levels. Our remaining five office properties are located in Fairfield County, Connecticut and Westchester County, New York, encompassing in the aggregate approximately 1.8 million rentable square feet. The majority of square footage for these five properties is located in densely populated metropolitan communities with immediate access to mass transportation. Additionally, we have entitled land at the Stamford Transportation Center in Stamford, Connecticut, adjacent to one of our office properties, that will support the development of an approximately 380,000 rentable square foot office building and garage. As of September 30, 2019 , our portfolio included four standalone retail properties located in Manhattan and two standalone retail properties located in the city center of Westport, Connecticut, encompassing 205,595 rentable square feet in the aggregate. We were organized as a Delaware limited partnership on November 28, 2011 and operations commenced upon completion of the initial public offering of ESRT’s Class A common stock and related formation transactions on October 7, 2013. ESRT, as the sole general partner in our company, has responsibility and discretion in the management and control of our company, and our limited partners, in such capacity, have no authority to transact business for, or participate in the management activities, of our company. As of September 30, 2019 , ESRT owned approximately 59.2% of our operating partnership units.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies There have been no material changes to the summary of significant accounting policies included in the section entitled "Summary of Significant Accounting Policies" in our December 31, 2018 Annual Report on Form 10-K, with the exception of the adoption of Financial Accounting Standards Board ("FASB") Topic 842, Lease Accounting on January 1, 2019. We adopted FASB Topic 842, Lease Accounting, using the modified retrospective approach on January 1, 2019 and elected to apply the transition provisions of the standard at adoption. As such, the prior period amounts presented under Topic 840 were not restated to conform with the 2019 presentation. We adopted the practical expedient in Topic 842, which allows us to avoid separating lease and non-lease rental income. Consequently, all rental income earned pursuant to tenant leases in 2019 is reflected as one category, “Rental Revenue,” in the 2019 consolidated statement of income. Topic 842 also requires that a lessee recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The adoption of this standard resulted in the recognition of right-of-use assets and lease liabilities for our operating leases on our balance sheet of approximately $29.5 million . In addition, under Topic 842, lessors may only capitalize incremental direct leasing costs. As a result, we no longer capitalize our non-contingent leasing costs and instead expense these costs as incurred. These costs totaled $3.7 million for the nine months ended September 30, 2019. Basis of Quarterly Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), for interim financial information, and with the rules and regulations of the Securities and Exchange Commission (the "SEC"). Accordingly, certain information and footnote disclosures required by GAAP for complete financial statements have been condensed or omitted in accordance with such rules and regulations. In the opinion of management, all adjustments and eliminations (including intercompany balances and transactions), consisting of normal recurring adjustments, considered necessary for the fair presentation of the financial statements have been included. The results of operations for the periods presented are not necessarily indicative of the results that may be expected for the corresponding full years. These financial statements should be read in conjunction with the financial statements and accompanying notes included in the financial statements for the year ended December 31, 2018 contained in our Annual Report on Form 10-K. We do not consider our business to be subject to material seasonal fluctuations, except that our observatory business is subject to tourism seasonality. During the past ten years, approximately 16.0% to 18.0% of our annual observatory revenue was realized in the first quarter, 26.0% to 28.0% was realized in the second quarter, 31.0% to 33.0% was realized in the third quarter and 23.0% to 25.0% was realized in the fourth quarter. We consolidate entities in which we have a controlling financial interest. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, authority to make decisions, and contractual and substantive participating rights of the partners/members. For variable interest entities ("VIE"), we consolidate the entity if we are deemed to have a variable interest in the entity and through that interest we are deemed the primary beneficiary. The primary beneficiary of a VIE 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. The primary beneficiary is required to consolidate the VIE. We had no VIEs as of September 30, 2019 and December 31, 2018. We will assess the accounting treatment for each investment we may have in the future. This assessment will include a review of each entity’s organizational agreement to determine which party has what rights and whether those rights are protective or participating. For all VIEs, we will review such agreements in order to determine which party has the power to direct the activities that most significantly impact the entity’s economic performance and benefit. In situations where we or our partner could approve, among other things, the annual budget, or leases that cover more than a nominal amount of space relative to the total rentable space at each property, we would not consolidate the investment as we consider these to be substantive participation rights that result in shared power of the activities that would most significantly impact the performance and benefit of such joint venture investment. A non-controlling interest in a consolidated subsidiary is defined as the portion of the equity (net assets) in a subsidiary not attributable, directly or indirectly, to a parent. Non-controlling interests are required to be presented as a separate component of equity in the condensed consolidated balance sheets and in the condensed consolidated statements of income by requiring earnings and other comprehensive income to be attributed to controlling and non-controlling interests. Accounting Estimates The preparation of the condensed consolidated financial statements in accordance with GAAP requires management to use estimates and assumptions that in certain circumstances affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported revenues and expenses. Significant items subject to such estimates and assumptions include allocation of the purchase price of acquired real estate properties among tangible and intangible assets, determination of the useful life of real estate properties and other long-lived assets, valuation and impairment analysis of commercial real estate properties, right of use assets and other long-lived assets, estimate of tenant expense reimbursements, valuation of the allowance for doubtful accounts, and valuation of derivative instruments, ground lease liabilities, senior unsecured notes, mortgage notes payable, unsecured term loan and revolving credit facilities, and equity based compensation. These estimates are prepared using management’s best judgment, after considering past, current, and expected events and economic conditions. Actual results could differ from those estimates. Recently Issued or Adopted Accounting Standards During August 2018, the FASB issued Accounting Standards Update ("ASU") No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force), which contain amendments that align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). Accordingly, for entities in a hosting arrangement that is a service contract, costs for implementation activities in the application development stage are capitalized depending on the nature of the costs, while costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. The amendments in ASU No. 2018-15 also require the entity (customer) to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement. The amendments are effective for public business entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption of the amendments is permitted, including adoption in any interim period. The amendments in ASU No. 2018-15 should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We are evaluating the impact of adopting this new accounting standard on our consolidated financial statements. During January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which contain amendments that modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. Because these amendments eliminate Step 2 from the goodwill impairment test, they should reduce the cost and complexity of evaluating goodwill for impairment. ASU No. 2017-04 should be applied on a prospective basis and the amendments adopted for the annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We are evaluating the impact of adopting this new accounting standard on our consolidated financial statements. During June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which contains amendments that replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU No. 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Earlier adoption as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, is permitted. The amendments must be adopted through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified retrospective approach). We do not anticipate the adoption of this new accounting standard to have a material impact on our consolidated financial statements. During February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires that a lessee recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. In addition, lessors may only capitalize incremental direct leasing costs. Subsequent amendments to ASU No. 2016-02 also provide lessors with a practical expedient, by class of underlying asset, to not separate nonlease components from the associated lease component provided that (1) the timing and pattern of transfer are the same for the nonlease components and associated lease component and (2) the lease component, if accounted separately, would be classified as an operating lease. We adopted this standard and related amendments on January 1, 2019 and elected the available practical expedients. Such adoption resulted in the recognition of right-of-use assets and lease liabilities for our operating leases on our balance sheet of approximately $29.5 million .

Deferred Costs, Acquired Lease

Deferred Costs, Acquired Lease Intangibles and Goodwill	9 Months Ended
	Sep. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs, Acquired Lease Intangibles and Goodwill	Deferred Costs, Acquired Lease Intangibles and Goodwill Deferred costs, net, consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Leasing costs $ 185,698 $ 178,120 Acquired in-place lease value and deferred leasing costs 206,026 214,550 Acquired above-market leases 49,906 52,136 441,630 444,806 Less: accumulated amortization (222,651 ) (209,839 ) Total deferred costs, net, excluding net deferred financing costs $ 218,979 $ 234,967 At September 30, 2019 and December 31, 2018, $4.7 million and $6.3 million , respectively, of net deferred financing costs associated with the unsecured revolving credit facility was included in deferred costs, net on the condensed consolidated balance sheet. Amortization expense related to deferred leasing costs and acquired deferred leasing costs was $6.2 million and $6.3 million for the three months ended September 30, 2019 and 2018, respectively, and $18.3 million and $18.4 million for the nine months ended September 30, 2019 and 2018, respectively. Amortization expense related to acquired lease intangibles was $2.4 million and $2.9 million for the three months ended September 30, 2019 and 2018, respectively, and $8.2 million and $9.3 million for the nine months ended September 30, 2019 and 2018, respectively. Amortizing acquired intangible assets and liabilities consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Acquired below-market ground leases $ 396,916 $ 396,916 Less: accumulated amortization (42,392 ) (36,518 ) Acquired below-market ground leases, net $ 354,524 $ 360,398 September 30, 2019 December 31, 2018 Acquired below-market leases $ (113,625 ) $ (118,462 ) Less: accumulated amortization 70,970 66,012 Acquired below-market leases, net $ (42,655 ) $ (52,450 ) Rental revenue related to the amortization of below-market leases, net of above-market leases, was $1.7 million and $1.7 million for the three months ended September 30, 2019 and 2018, respectively, and $5.8 million and $4.4 million for the nine months ended September 30, 2019 and 2018, respectively. As of September 30, 2019 , we had goodwill of $491.5 million . Goodwill was allocated $227.5 million to the observatory reportable segment and $264.0 million to the real estate segment.

Debt

Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt	Debt Debt consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): Principal Balance As of September 30, 2019 September 30, 2019 December 31, 2018 Stated Effective (1) Maturity (2) Mortgage debt collateralized by: Fixed rate mortgage debt Metro Center $ 90,205 $ 91,838 3.59 % 3.67 % 11/5/2024 10 Union Square 50,000 50,000 3.70 % 3.97 % 4/1/2026 1542 Third Avenue 30,000 30,000 4.29 % 4.53 % 5/1/2027 First Stamford Place (3) 180,000 180,000 4.28 % 4.44 % 7/1/2027 1010 Third Avenue and 77 West 55th Street 38,440 38,995 4.01 % 4.21 % 1/5/2028 10 Bank Street 33,138 33,779 4.23 % 4.36 % 6/1/2032 383 Main Avenue 30,000 30,000 4.44 % 4.55 % 6/30/2032 1333 Broadway 160,000 160,000 4.21 % 4.29 % 2/5/2033 Total mortgage debt 611,783 614,612 Senior unsecured notes - exchangeable — 250,000 — — — Senior unsecured notes: (6) Series A 100,000 100,000 3.93 % 3.96 % 3/27/2025 Series B 125,000 125,000 4.09 % 4.12 % 3/27/2027 Series C 125,000 125,000 4.18 % 4.21 % 3/27/2030 Series D 115,000 115,000 4.08 % 4.11 % 1/22/2028 Series E 160,000 160,000 4.26 % 4.27 % 3/22/2030 Series F 175,000 175,000 4.44 % 4.45 % 3/22/2033 Unsecured revolving credit facility (6) — — (4) (4) 8/29/2021 Unsecured term loan facility (6) 265,000 265,000 (5) (5) 8/29/2022 Total principal 1,676,783 1,929,612 Unamortized discount, net of unamortized premium — (1,647 ) Deferred financing costs, net (7,606 ) (9,032 ) Total $ 1,669,177 $ 1,918,933 ______________ (1) The effective rate is the yield as of September 30, 2019 , including the effects of debt issuance costs and the amortization of the fair value of debt adjustment. (2) Pre-payment is generally allowed for each loan upon payment of a customary pre-payment penalty. (3) Represents a $164 million mortgage loan bearing interest at 4.09% and a $16 million loan bearing interest at 6.25% . (4) At September 30, 2019 , the unsecured revolving credit facility bears a floating rate at 30 day LIBOR plus 1.10% . The rate at September 30, 2019 was 3.12% . (5) The unsecured term loan facility bears a floating rate at 30 day LIBOR plus 1.20% . Pursuant to an interest rate swap agreement, the LIBOR rate is fixed at 2.1485% through maturity. The rate at September 30, 2019 was 3.35% . (6) At September 30, 2019 , we were in compliance with all debt covenants. Principal Payments Aggregate required principal payments at September 30, 2019 are as follows (amounts in thousands): Year Amortization Maturities Total 2019 $ 961 $ — $ 961 2020 3,938 — 3,938 2021 4,090 — 4,090 2022 5,628 265,000 270,628 2023 7,876 — 7,876 Thereafter 33,868 1,355,422 1,389,290 Total $ 56,361 $ 1,620,422 $ 1,676,783 Deferred Financing Costs Deferred financing costs, net, consisted of the following at September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Financing costs $ 25,315 $ 25,315 Less: accumulated amortization (12,991 ) (10,027 ) Total deferred financing costs, net $ 12,324 $ 15,288 At September 30, 2019 and December 31, 2018, $4.7 million and $6.3 million , respectively, of net deferred financing costs associated with the unsecured revolving credit facility was included in deferred costs, net on the condensed consolidated balance sheet. Amortization expense related to deferred financing costs was $0.9 million and $1.1 million for the three months ended September 30, 2019 and 2018, respectively, and $2.9 million and $3.1 million for the nine months ended September 30, 2019 and 2018, respectively. Unsecured Revolving Credit and Term Loan Facility During August 2017, we entered into an amended and restated senior unsecured revolving credit and term loan facility (the “Facility”) with Bank of America, N.A., as administrative agent, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC as Joint Lead Arrangers and Joint Bookrunners, Wells Fargo, National Association and Capital One, National Association, as co-syndication agents, and the lenders party thereto. The Facility is in the original principal amount of up to $1.365 billion , which consists of a $1.1 billion revolving credit facility and a $265 million term loan facility. We may request the Facility be increased through one or more increases in the revolving credit facility or one or more increases in the term loan facility or the addition of new pari passu term loan tranches, for a maximum aggregate principal amount not to exceed $1.75 billion . The initial maturity of the unsecured revolving credit facility is August 2021. We have the option to extend the initial term for up to two additional 6 -month periods, subject to certain conditions, including the payment of an extension fee equal to 0.0625% and 0.075% of the then outstanding commitments under the unsecured revolving credit facility on the first and the second extensions, respectively. T he term loan facility matures in August 2022. We may prepay the loans under the Facility at any time, subject to reimbursement of the lenders’ breakage and redeployment costs in the case of prepayment of Eurodollar Rate borrowings. Exchangeable Senior Notes During August 2014, we issued $250.0 million 2.625% Exchangeable Senior Notes (“ 2.625% Exchangeable Senior Notes”) that were due on August 15, 2019. The 2.625% Exchangeable Senior Notes were exchangeable into cash, shares of Class A common stock or a combination of cash and shares of Class A common stock, at our election. On August 15, 2019, we settled the principal amount of the 2.625% Exchangeable Senior Notes in cash. For the three and nine months ended September 30, 2019 , total interest expense related to the 2.625% Exchangeable Senior Notes was $1.2 million and $6.1 million , respectively, consisting of (i) the contractual interest expense of $0.8 million and $4.1 million , respectively, (ii) the additional non-cash interest expense of $0.3 million and $1.6 million , respectively, relating to the accretion of the debt discount and (iii) the amortization of deferred financing costs of $0.1 million and $0.4 million , respectively. For the three and nine months ended September 30, 2018 , total interest expense related to the 2.625% Exchangeable Senior Notes was $2.4 million and $7.3 million , respectively, consisting of (i) the contractual interest expense of $1.6 million and $4.9 million , respectively, (ii) the additional non-cash interest expense of $0.7 million and $2.0 million , respectively, relating to the accretion of the debt discount, and (iii) the amortization of deferred financing costs of $0.1 million and $0.4 million , respectively.

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	9 Months Ended
	Sep. 30, 2019
Payables and Accruals [Abstract]
Accounts Payable and Accrued Expenses	Accounts Payable and Accrued Expenses Accounts payable and accrued expenses consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Accrued capital expenditures $ 77,142 $ 85,242 Accounts payable and accrued expenses 34,328 34,585 Interest rate swap agreements liability 28,850 5,243 Accrued interest payable 2,851 4,990 Due to affiliated companies 30 616 Total accounts payable and accrued expenses $ 143,201 $ 130,676

Financial Instruments and Fair

Financial Instruments and Fair Values	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Values	Financial Instruments and Fair Values Derivative Financial Instruments We use derivative financial instruments primarily to manage interest rate risk and such derivatives are not considered speculative. These derivative instruments are typically in the form of interest rate swap and forward agreements and the primary objective is to minimize interest rate risks associated with investing and financing activities. The counterparties of these arrangements are major financial institutions with which we may also have other financial relationships. We are exposed to credit risk in the event of non-performance by these counterparties; however, we currently do not anticipate that any of the counterparties will fail to meet their obligations. We have agreements with our derivative counterparties that contain a provision where if we either default or are capable of being declared in default on any of our indebtedness, then we could also be declared in default on our derivative obligations. As of September 30, 2019 , the fair value of derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was $29.3 million . If we had breached any of these provisions at September 30, 2019 , we could have been required to settle our obligations under the agreements at their termination value of $29.3 million . As of September 30, 2019 and December 31, 2018, we had interest rate LIBOR swaps with an aggregate notional value of $515.0 million and $515.0 million , respectively. The notional value does not represent exposure to credit, interest rate or market risks. As of September 30, 2019 , the fair value of our derivative instruments amounted to $(28.8) million which is included in accounts payable and accrued expenses on the condensed consolidated balance sheet. As of December 31, 2018, the fair value of our derivative instruments amounted to $2.5 million which is included in prepaid expenses and other assets and $(5.2) million which is included in accounts payable and accrued expenses on the condensed consolidated balance sheet. These interest rate swaps have been designated as cash flow hedges and hedge the variability in future cash flows associated with our existing variable-rate term loan facility and with a forecast refinancing of our exchangeable senior notes. As of September 30, 2019 and 2018, our cash flow hedges are deemed highly effective and a net unrealized gain (loss) of $(5.9) million and $4.3 million for the three months ended September 30, 2019 and 2018, respectively, and a net unrealized gain (loss) of $(25.4) million and $11.4 million for the nine months ended September 30, 2019 and 2018, respectively, relating to both active and terminated hedges of interest rate risk, are reflected in the condensed consolidated statements of comprehensive income. Amounts reported in accumulated other comprehensive income (loss) related to derivatives will be reclassified to interest expense as interest payments are made on the debt. We estimate that $(5.6) million net loss of the current balance held in accumulated other comprehensive income (loss) will be reclassified into interest expense within the next 12 months. The table below summarizes the terms of agreements and the fair values of our derivative financial instruments as of September 30, 2019 and December 31, 2018 (dollar amounts in thousands): September 30, 2019 December 31, 2018 Derivative Notional Amount Receive Rate Pay Rate Effective Date Expiration Date Asset Liability Asset Liability Interest rate swap $ 265,000 1 Month LIBOR 2.1485% August 31, 2017 August 24, 2022 $ — $ (5,594 ) $ 2,536 $ — Interest rate swap 125,000 3 Month LIBOR 2.9580% July 1, 2019 July 1, 2026 — (11,628 ) — (2,623 ) Interest rate swap 125,000 3 Month LIBOR 2.9580% July 1, 2019 July 1, 2026 — (11,628 ) — (2,620 ) $ — $ (28,850 ) $ 2,536 $ (5,243 ) The table below shows the effect of our derivative financial instruments designated as cash flow hedges on accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2019 and 2018 (amounts in thousands): Three Months Ended Nine Months Ended Effects of Cash Flow Hedges September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Amount of gain (loss) recognized in other comprehensive income (loss) $ (6,256 ) $ 3,884 $ (25,992 ) $ 9,827 Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense (319 ) (427 ) (637 ) (1,562 ) The table below shows the effect of our derivative financial instruments designated as cash flow hedges on the condensed consolidated statements of income for the three and nine months ended September 30, 2019 and 2018 (amounts in thousands): Three Months Ended Nine Months Ended Effects of Cash Flow Hedges September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Total interest (expense) presented in the condensed consolidated statements of income in which the effects of cash flow hedges are recorded $ (19,426 ) $ (20,658 ) $ (60,712 ) $ (58,774 ) Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense (319 ) (427 ) (637 ) (1,562 ) Fair Valuation The estimated fair values at September 30, 2019 and December 31, 2018 were determined by management, using available market information and appropriate valuation methodologies. Considerable judgment is necessary to interpret market data and develop estimated fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts we could realize on disposition of the financial instruments. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. The fair value of our senior unsecured notes - exchangeable was derived from quoted prices in active markets and is classified as Level 2 since trading volumes are low. The fair value of derivative instruments is determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. Although the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by ourselves and our counterparties. The impact of such credit valuation adjustments, determined based on the fair value of each individual contract, was not significant to the overall valuation. As a result, all of our derivatives were classified as Level 2 of the fair value hierarchy. The fair value of our mortgage notes payable, senior unsecured notes - Series A, B, C, D, E and F, unsecured term loan facility and ground lease liabilities which are determined using Level 3 inputs, are estimated by discounting the future cash flows using current interest rates at which similar borrowings could be made to us. The following tables summarize the carrying and estimated fair values of our financial instruments as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 Estimated Fair Value Carrying Total Level 1 Level 2 Level 3 Interest rate swaps included in prepaid expenses and other assets $ — $ — $ — $ — $ — Interest rate swaps included in accounts payable and accrued expenses 28,850 28,850 — 28,850 — Mortgage notes payable 606,313 643,159 — — 643,159 Senior unsecured notes - Series A, B, C, D, E and F 798,347 861,245 — — 861,245 Unsecured term loan facility 264,517 265,000 — — 265,000 Ground lease liabilities 29,355 29,355 — — 29,355 December 31, 2018 Estimated Fair Value Carrying Total Level 1 Level 2 Level 3 Interest rate swaps included in prepaid expenses and other assets $ 2,536 $ 2,536 $ — $ 2,536 $ — Interest rate swaps included in accounts payable and accrued expenses 5,243 5,243 — 5,243 — Mortgage notes payable 608,567 597,424 — — 597,424 Senior unsecured notes - Exchangeable 247,930 250,625 — 250,625 — Senior unsecured notes - Series A, B, C, D, E and F 798,289 795,662 — — 795,662 Unsecured term loan facility 264,147 265,000 — — 265,000 Disclosure about the fair value of financial instruments is based on pertinent information available to us as of September 30, 2019

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Leases Lessor We lease various spaces to tenants over terms ranging from one to 21 years. Certain leases have renewal options for additional terms. The leases provide for base monthly rentals and reimbursements for real estate taxes, escalations linked to the consumer price index or common area maintenance known as operating expense escalation. Operating expense reimbursements are reflected in our September 30, 2019 condensed consolidated statement of income as rental revenue and in our September 30, 2018 condensed consolidated statement of income as tenant expense reimbursement. Rental revenue includes fixed and variable payments. Fixed payments primarily relate to base rent and variable payments primarily relate to tenant expense reimbursements for certain property operating costs. The components of rental revenue for the three and nine months ended September 30, 2019 are as follows (amounts in thousands): Three months ended September 30, 2019 Nine months ended September 30, 2019 Fixed payments $ 129,030 $ 380,647 Variable payments 21,195 54,066 Total rental revenue $ 150,225 $ 434,713 As of September 30, 2019, we were entitled to the following future contractual minimum lease payments (excluding operating expense reimbursements) on non-cancellable operating leases to be received which expire on various dates through 2038 (amounts in thousands): Remainder of 2019 $ 124,080 2020 496,805 2021 477,068 2022 446,300 2023 419,857 Thereafter 1,954,810 $ 3,918,920 As of December 31, 2018, we were entitled to the following future contractual minimum lease payments (excluding operating expense reimbursements) on non-cancellable operating leases to be received which expire on various dates through 2038 (amounts in thousands): 2019 $ 485,441 2020 460,127 2021 423,365 2022 391,395 2023 362,738 Thereafter 1,536,461 $ 3,659,527 The above future minimum lease payments exclude tenant recoveries, amortization of deferred rent receivables and the net accretion of above-below-market lease intangibles. Some leases are subject to termination options generally upon payment of a termination fee. The preceding tables are prepared assuming such options are not exercised. Lessee We make payments under ground leases related to three of our properties. Minimum rent is expensed on a straight-line basis over the non-cancellable term of the leases. The ground leases are due to expire between the years 2050 and 2077, inclusive of extension options, and have no variable payments or residual value guarantees. As of September 30, 2019, our balance sheet included $29.4 million and $29.4 million in right-of-use assets and lease liabilities, respectively, that are associated with these three ground leases. The rate implicit in the lease was not determinable for any of these ground leases and accordingly, we measured the related lease liabilities using discount rates based on estimated incremental borrowing rates. Our estimates required significant judgment given that the lease terms of our ground leases are significantly longer than the terms of borrowings on a fully-collateralized basis and considered factors such as U.S. Treasury rates and our own credit rating. Information relating to the measurement of our lease liabilities as of September 30, 2019 are as follows: Weighted average remaining lease term (in years) 50.8 Weighted average discount rate 4.49 % Cash paid for operating leases nine months ended September 30, 2019 (in thousands) $ 1,139 Future minimum lease payments to be paid over the terms of the leases as of September 30, 2019 are as follows (amounts in thousands): Remainder of 2019 $ 380 2020 1,518 2021 1,518 2022 1,518 2023 1,518 Thereafter 68,298 Total undiscounted cash flows 74,750 Present value discount (45,395 ) Ground lease liabilities $ 29,355 Future minimum lease payments to be paid over the terms of the leases as of December 31, 2018 are as follows (amounts in thousands): 2019 $ 1,518 2020 1,518 2021 1,518 2022 1,518 2023 1,518 Thereafter 68,298 $ 75,888
Leases	Leases Lessor We lease various spaces to tenants over terms ranging from one to 21 years. Certain leases have renewal options for additional terms. The leases provide for base monthly rentals and reimbursements for real estate taxes, escalations linked to the consumer price index or common area maintenance known as operating expense escalation. Operating expense reimbursements are reflected in our September 30, 2019 condensed consolidated statement of income as rental revenue and in our September 30, 2018 condensed consolidated statement of income as tenant expense reimbursement. Rental revenue includes fixed and variable payments. Fixed payments primarily relate to base rent and variable payments primarily relate to tenant expense reimbursements for certain property operating costs. The components of rental revenue for the three and nine months ended September 30, 2019 are as follows (amounts in thousands): Three months ended September 30, 2019 Nine months ended September 30, 2019 Fixed payments $ 129,030 $ 380,647 Variable payments 21,195 54,066 Total rental revenue $ 150,225 $ 434,713 As of September 30, 2019, we were entitled to the following future contractual minimum lease payments (excluding operating expense reimbursements) on non-cancellable operating leases to be received which expire on various dates through 2038 (amounts in thousands): Remainder of 2019 $ 124,080 2020 496,805 2021 477,068 2022 446,300 2023 419,857 Thereafter 1,954,810 $ 3,918,920 As of December 31, 2018, we were entitled to the following future contractual minimum lease payments (excluding operating expense reimbursements) on non-cancellable operating leases to be received which expire on various dates through 2038 (amounts in thousands): 2019 $ 485,441 2020 460,127 2021 423,365 2022 391,395 2023 362,738 Thereafter 1,536,461 $ 3,659,527 The above future minimum lease payments exclude tenant recoveries, amortization of deferred rent receivables and the net accretion of above-below-market lease intangibles. Some leases are subject to termination options generally upon payment of a termination fee. The preceding tables are prepared assuming such options are not exercised. Lessee We make payments under ground leases related to three of our properties. Minimum rent is expensed on a straight-line basis over the non-cancellable term of the leases. The ground leases are due to expire between the years 2050 and 2077, inclusive of extension options, and have no variable payments or residual value guarantees. As of September 30, 2019, our balance sheet included $29.4 million and $29.4 million in right-of-use assets and lease liabilities, respectively, that are associated with these three ground leases. The rate implicit in the lease was not determinable for any of these ground leases and accordingly, we measured the related lease liabilities using discount rates based on estimated incremental borrowing rates. Our estimates required significant judgment given that the lease terms of our ground leases are significantly longer than the terms of borrowings on a fully-collateralized basis and considered factors such as U.S. Treasury rates and our own credit rating. Information relating to the measurement of our lease liabilities as of September 30, 2019 are as follows: Weighted average remaining lease term (in years) 50.8 Weighted average discount rate 4.49 % Cash paid for operating leases nine months ended September 30, 2019 (in thousands) $ 1,139 Future minimum lease payments to be paid over the terms of the leases as of September 30, 2019 are as follows (amounts in thousands): Remainder of 2019 $ 380 2020 1,518 2021 1,518 2022 1,518 2023 1,518 Thereafter 68,298 Total undiscounted cash flows 74,750 Present value discount (45,395 ) Ground lease liabilities $ 29,355 Future minimum lease payments to be paid over the terms of the leases as of December 31, 2018 are as follows (amounts in thousands): 2019 $ 1,518 2020 1,518 2021 1,518 2022 1,518 2023 1,518 Thereafter 68,298 $ 75,888

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings Except as described below, as of September 30, 2019 , we were not involved in any material litigation, nor, to our knowledge, was any material litigation threatened against us or our properties, other than routine litigation arising in the ordinary course of business such as disputes with tenants. We believe that the costs and related liabilities, if any, which may result from such actions will not materially affect our condensed consolidated financial position, operating results or liquidity. As previously disclosed, in October 2014, 12 former investors in Empire State Building Associates L.L.C. (“ESBA”), which prior to the initial public offering of our company (the "Offering"), owned the fee title to the Empire State Building, filed an arbitration with the American Arbitration Association against Peter L. Malkin, Anthony E. Malkin, Thomas N. Keltner, Jr., and our subsidiary ESRT MH Holdings LLC, the former supervisor of ESBA, as respondents. The statement of claim (also filed later in federal court in New York for the expressed purpose of tolling the statute of limitations) alleges breach of fiduciary duty and related claims in connection with the Offering and formation transactions and seeks monetary damages and declaratory relief. These investors had opted out of a prior class action bringing similar claims that was settled with court approval. The respondents filed an answer and counterclaims. In March 2015, the federal court action was stayed on consent of all parties pending the arbitration. Arbitration hearings for a select number of sessions started in May 2016 and concluded in August 2018. Post-hearing briefing is currently scheduled to be completed by March 2020. The respondents believe the allegations in the arbitration are entirely without merit, and they intend to continue to defend them vigorously. Pursuant to indemnification agreements which were made with our directors, executive officers and chairman emeritus as part of our formation transactions, Anthony E. Malkin, Peter L. Malkin and Thomas N. Keltner, Jr. have defense and indemnity rights from us with respect to this arbitration. Unfunded Capital Expenditures At September 30, 2019 , we estimate that we will incur approximately $144.2 million of capital expenditures (including tenant improvements and leasing commissions) on our properties pursuant to existing lease agreements. We expect to fund these capital expenditures with operating cash flow, additional property level mortgage financings, our unsecured credit facility, cash on hand and other borrowings. Future property acquisitions may require substantial capital investments for refurbishment and leasing costs. We expect that these financing requirements will be met in a similar fashion. Concentration of Credit Risk Financial instruments that subject us to credit risk consist primarily of cash and cash equivalents, restricted cash, short-term investments, tenant and other receivables and deferred rent receivables. At September 30, 2019 , we held on deposit at various major financial institutions cash and cash equivalents and restricted cash balances in excess of amounts insured by the Federal Deposit Insurance Corporation. Asset Retirement Obligations We are required to accrue costs that we are legally obligated to incur on retirement of our properties which result from acquisition, construction, development and/or normal operation of such properties. Retirement includes sale, abandonment or disposal of a property. Under that standard, a conditional asset retirement obligation represents a legal obligation to perform an asset retirement activity in which the timing and/or method of settlement is conditional on a future event that may or may not be within a company’s control and a liability for a conditional asset retirement obligation must be recorded if the fair value of the obligation can be reasonably estimated. Environmental site assessments and investigations have identified asbestos or asbestos-containing building materials in certain of our properties. As of September 30, 2019 , management has no plans to remove or alter these properties in a manner that would trigger federal and other applicable regulations for asbestos removal, and accordingly, the obligations to remove the asbestos or asbestos-containing building materials from these properties have indeterminable settlement dates. As such, we are unable to reasonably estimate the fair value of the associated conditional asset retirement obligation. However, ongoing asbestos abatement, maintenance programs and other required documentation are carried out as required and related costs are expensed as incurred. Other Environmental Matters Certain of our properties have been inspected for soil contamination due to pollutants, which may have occurred prior to our ownership of these properties or subsequently in connection with its development and/or its use. Required remediation to such properties has been completed, and as of September 30, 2019 , management believes that there are no obligations related to environmental remediation other than maintaining the affected sites in conformity with the relevant authority’s mandates and filing the required documents. All such maintenance costs are expensed as incurred. We expect that resolution of the environmental matters relating to the above will not have a material impact on our business, assets, consolidated financial condition, results of operations or liquidity. However, we cannot be certain that we have identified all environmental liabilities at our properties, that all necessary remediation actions have been or will be undertaken at our properties or that we will be indemnified, in full or at all, in the event that such environmental liabilities arise. Insurance Coverage

Capital

Capital	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note Disclosure, Disclosure of Compensation Related Costs, Share-based Payments and Earnings Per Share [Abstract]
Capital	Capital As of September 30, 2019 , there were 304,256,572 operating partnership units outstanding, of which 180,149,553 , or 59.2% , were owned by ESRT and 124,107,019 , or 40.8% , were owned by other partners, including ESRT directors, members of senior management and other employees. On May 16, 2019, the Empire State Realty Trust, Inc. Empire State Realty OP, L.P. 2019 Equity Incentive Plan (“2019 Plan”) was approved by our shareholders. The 2019 Plan provides for grants to directors, employees and consultants of ESRT and the Operating Partnership, including options, restricted stock, restricted stock units, stock appreciation rights, performance awards, dividend equivalents and other equity-based awards. An aggregate of approximately 11.0 million shares of ESRT common stock is authorized for issuance under awards granted pursuant to the 2019 Plan. We will not issue any new equity awards under the First Amended and Restated Empire State Realty Trust, Inc. and Empire State Realty OP, L.P. 2013 Equity Incentive Plan ("2013 Plan", and collectively with the 2019 Plan, "the Plans"). The shares of ESRT Class A common stock underlying any awards under the 2019 Plan and the 2013 Plan that are forfeited, canceled or otherwise terminated, other than by exercise, will be added back to the shares of ESRT Class A common stock available for issuance under the 2019 Plan. Shares tendered or held back upon exercise of a stock option or settlement of an award under the 2019 Plan and the 2013 Plan to cover the exercise price or tax withholding and shares subject to a stock appreciation right that are not issued in connection with the stock settlement of the stock appreciation right upon exercise thereof, will not be added back to the shares of ESRT Class A common stock available for issuance under the 2019 Plan. In addition, shares of ESRT Class A common stock repurchased on the open market will not be added back to the shares of ESRT Class A common stock available for issuance under the 2019 Plan. Long-term incentive plan ("LTIP") units are a special class of partnership interests. Each LTIP unit awarded will be deemed equivalent to an award of one share of ESRT stock under the Plans, reducing the availability for other equity awards on a one-for-one basis. The vesting period for LTIP units, if any, will be determined at the time of issuance. Under the terms of the LTIP units, we will revalue for tax purposes its assets upon the occurrence of certain specified events, and any increase in valuation from the time of grant until such event will be allocated first to the holders of LTIP units to equalize the capital accounts of such holders with the capital accounts of unitholders. Subject to any agreed upon exceptions, once vested and having achieved parity with unitholders, LTIP units are convertible into Series PR operating partnership units on a one-for-one basis. LTIP units subject to time based vesting, whether vested or not, receive the same per unit distributions as operating partnership units, which equal per share dividends (both regular and special) on our common stock. Performance based LTIP units receive 10% of such distributions currently, unless and until such LTIP units are earned based on performance, at which time they will receive the accrued and unpaid 90% and will commence receiving 100% of such distributions thereafter. Private Perpetual Preferred Units During September 2019, we commenced an offer to exchange 15,000,000 newly issued Series 2019 Private Perpetual Preferred Units ("Series 2019 Preferred Units") for outstanding Series ES operating partnership units, Series 60 operating partnership units, Series 250 operating partnership units and Series PR operating partnership units on a one-for-one basis, in reliance upon an exemption from registration under Section 3(a)(9) of the Securities Act of 1933, as amended. The Series 2019 Preferred Units have a liquidation preference of $13.52 per unit and are entitled to receive cumulative preferential annual cash distributions of $0.70 per unit payable in arrears on a quarterly basis. The Series 2019 Preferred Units are not redeemable at the option of the holders and are redeemable at our option only upon the occurrence of certain events involving a change in control and the payment of an amount equal to 200% of such liquidation preference. The offering is set to expire on November 22, 2019. Distributions Total distributions paid to OP unitholders were $31.9 million and $95.7 million for the three and nine months ended September 30, 2019 , respectively, and $31.9 million and $95.3 million for the three and nine months ended September 30, 2018, respectively. Total distributions paid to preferred unitholders were $0.2 million and $0.7 million for the three and nine months ended September 30, 2019 , respectively, and $0.2 million and $0.7 million for the three and nine months ended September 30, 2018, respectively. Incentive and Share-Based Compensation The Plans provide for grants to directors, employees and consultants consisting of stock options, restricted stock, dividend equivalents, stock payments, performance shares, LTIP units, stock appreciation rights and other incentive awards. An aggregate of 11.0 million shares of ESRT common stock is authorized for issuance under awards granted pursuant to the 2019 Plan, and as of September 30, 2019 , 11.5 million shares of ESRT common stock remain available for future issuance. In March 2019, we made grants of LTIP units to executive officers under the 2013 Plan. At such time, we granted to executive officers a total of 461,693 LTIP units that are subject to time-based vesting and 1,806,520 LTIP units that are subject to performance-based vesting, with fair market values of $6.4 million for the time-based vesting awards and $12.8 million for the performance-based vesting awards. In March 2019, we made grants of LTIP units and restricted stock to certain other employees under the 2013 Plan. At such time, we granted to certain other employees a total of 61,432 LTIP units and 69,358 shares of restricted stock that are subject to time-based vesting and 113,383 LTIP units that are subject to performance-based vesting, with fair market values of $2.0 million for the time-based vesting awards and $0.9 million for the performance-based vesting awards. The awards subject to time-based vesting vest ratably over four years from January 1, 2019, subject generally to the grantee's continued employment. The first installment vests on January 1, 2020 and the remainder will vest thereafter in three equal annual installments. The vesting of the LTIP units subject to performance-based vesting is based on the achievement of relative total stockholder return hurdles over a three -year performance period, commencing on January 1, 2019. Following the completion of the three -year performance period, our compensation committee will determine the number of LTIP units to which the grantee is entitled based on our performance relative to the performance hurdles set forth in the LTIP unit award agreements the grantee entered into in connection with the award grant. These units then vest in two installments, with the first installment vesting on January 1, 2022 and the second installment vesting on January 1, 2023, subject generally to the grantee's continued employment on those dates. Our named executive officers can elect to receive their annual incentive bonus in any combination of (i) cash or vested LTIP's at the face amount of such bonus or (ii) time-vesting LTIP's which would vest over three years , subject to continued employment, at 125% of such face amount. In March 2019, we made grants of LTIP units to executive officers under the 2013 Plan in connection with the 2018 bonus election program. We granted to executive officers a total of 334,952 LTIP units that are subject to time based vesting with a fair market value of $4.6 million . Of these LTIP units, 26,056 LTIP units vested immediately on the grant date and 308,896 LTIP units vest ratably over three years from January 1, 2019, subject generally to the grantee's continued employment. The first installment vests on January 1, 2020 and the remainder will vest thereafter in two equal annual installments. In May 2019, we made grants of LTIP units to our non-employee directors under the 2019 Plan. At such time, we granted a total of 70,746 LTIP units that are subject to time-based vesting with fair market values of $1.0 million . The awards vest ratably over three years from the date of the grant, subject generally to the director's continued service on our Board of Directors. Share-based compensation is measured at the fair value of the award on the date of grant and recognized as an expense on a straight-line basis over the vesting period. For the performance-based LTIP units, the fair value of the awards was estimated using a Monte Carlo Simulation model and discounted for the restriction period during which the LTIP units cannot be redeemed or transferred and the uncertainty regarding if, and when, the book capital account of the LTIP units will equal that of the common units. Our stock price, along with the prices of the comparative indexes, is assumed to follow the Geometric Brownian Motion Process. Geometric Brownian Motion is a common assumption when modeling in financial markets, as it allows the modeled quantity (in this case the stock price) to vary randomly from its current value and take any value greater than zero. The volatilities of the returns on our stock price and the comparative indexes were estimated based on implied volatilities and historical volatilities using a six -year look-back period. The expected growth rate of the stock prices over the performance period is determined with consideration of the risk free rate as of the grant date. For LTIP unit awards that are time-based, the fair value of the awards was estimated based on the fair value of our stock at the grant date discounted for the restriction period during which the LTIP units cannot be redeemed or transferred and the uncertainty regarding if, and when, the book capital account of the LTIP units will equal that of the common units. For restricted stock awards that are time-based, we estimate the stock compensation expense based on the fair value of the stock at the grant date. LTIP units and ESRT restricted stock issued during the nine months ended September 30, 2019 were valued at $27.9 million . The weighted-average per unit or share fair value was $9.55 for grants issued in 2019. The per unit or share granted in 2019 was estimated on the respective dates of grant using the following assumptions: an expected life from 2.0 to 5.3 years, a dividend rate of 2.40% , a risk-free interest rate from 2.48% to 2.63% , and an expected price volatility from 17.0% to 22.0% . No other stock options, dividend equivalents, or stock appreciation rights were issued or outstanding in 2019. The following is a summary of ESRT restricted stock and LTIP unit activity for the nine months ended September 30, 2019 : Restricted Stock LTIP Units Weighted Average Grant Fair Value Unvested balance at December 31, 2018 91,158 5,702,821 $ 9.68 Vested (35,724 ) (598,402 ) 15.98 Granted 69,358 2,848,726 9.55 Forfeited or unearned (5,762 ) (1,972,548 ) 7.34 Unvested balance at September 30, 2019 119,030 5,980,597 $ 9.72 The LTIP unit and ESRT restricted stock awards will immediately vest upon the later of (i) the date the grantee attains the age of 60 and (ii) the date on which grantee has first completed ten years of continuous service with our company or its affiliates. For award agreements that qualify, we recognize noncash compensation expense on the grant date for the time-based awards and ratably over the vesting period for the performance-based awards, and accordingly, we recognized $0.3 million and $1.8 million for the three and nine months ended September 30, 2019 , respectively, and $0.4 million and $1.7 million for the three and nine months ended September 30, 2018, respectively. Unrecognized compensation expense was $1.4 million at September 30, 2019 , which will be recognized over a weighted average period of 2.3 years. For the remainder of the LTIP unit and ESRT restricted stock awards, we recognize noncash compensation expense ratably over the vesting period, and accordingly, we recognized noncash compensation expense of $3.4 million and $13.6 million for the three and nine months ended September 30, 2019 , respectively, and $4.5 million and $12.4 million for the three and nine months ended September 30, 2018, respectively. Unrecognized compensation expense was $33.8 million at September 30, 2019 , which will be recognized over a weighted average period of 2.3 years. Earnings Per Unit Earnings per unit for the three and nine months ended September 30, 2019 and 2018 is computed as follows (amounts in thousands, except per share amounts): Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Numerator: Net income $ 26,784 $ 29,230 $ 55,570 $ 77,472 Private perpetual preferred unit distributions (234 ) (234 ) (702 ) (702 ) Earnings allocated to unvested units (243 ) (212 ) (646 ) (586 ) Net income attributable to common unitholders - basic and diluted $ 26,307 $ 28,784 $ 54,222 $ 76,184 Denominator: Weighted average units outstanding - basic 298,151 297,478 298,117 297,180 Effect of dilutive securities: Stock-based compensation plans — — — 1 Weighted average units outstanding - diluted 298,151 297,478 298,117 297,181 Earnings per share: Basic $ 0.09 $ 0.10 $ 0.18 $ 0.26 Diluted $ 0.09 $ 0.10 $ 0.18 $ 0.26 There were 452,457 and 288,053 antidilutive shares and LTIP units for the three and nine months ended September 30, 2019 , respectively, and 541,947 and 458,698 antidilutive shares and LTIP units for the three and nine months ended September 30, 2018, respectively.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Supervisory Fee Revenue We earned supervisory fees from entities affiliated with Anthony E. Malkin, our Chairman and Chief Executive Officer, of $0.2 million and $0.2 million for the three months ended September 30, 2019 and 2018, respectively, and $0.7 million and $0.9 million for the nine months ended September 30, 2019 and 2018, respectively. These fees are included within third-party management and other fees. Property Management Fee Revenue We earned property management fees from entities affiliated with Anthony E. Malkin of $0.1 million and $0.1 million for the three months ended September 30, 2019 and 2018, respectively, and $0.2 million and $0.3 million for the nine months ended September 30, 2019 and 2018, respectively. These fees are included within third-party management and other fees. Other We receive rent generally at market rental rate for 5,351 square feet of leased space from entities affiliated with Anthony E. Malkin at one of our properties. Under the lease, the tenant has the right to cancel such lease without special payment on 90 days’ notice. We also have a shared use agreement with such tenant, to occupy a portion of the leased premises as the office location for Peter L. Malkin, our chairman emeritus and employee, utilizing approximately 15% of the space, for which we pay to such tenant an allocable pro rata share of the cost. We also have agreements with these entities and excluded properties and businesses to provide them with general computer-related support services. Total revenue aggregated $0.1 million and $0.1 million for the three months ended September 30, 2019 and 2018, respectively, and $0.2 million and $0.3 million for the nine months ended September 30, 2019 and 2018, respectively. One of ESRT's directors, James D. Robinson IV, is a general partner in an investment fund, which owns more than a 10% economic and voting interest in one of our tenants, OnDeck Capital, with an annualized rent of $4.6 million as of September 30, 2019 .

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting We have identified two reportable segments: (1) real estate and (2) observatory. Our real estate segment includes all activities related to the ownership, management, operation, acquisition, redevelopment, repositioning and disposition of our traditional real estate assets. Our observatory segment includes the operation of the 86th and 102nd floor observatories at the Empire State Building. These two lines of businesses are managed separately because each business requires different support infrastructures, provides different services and has dissimilar economic characteristics such as investments needed, stream of revenues and marketing strategies. We account for intersegment sales and rent as if the sales or rent were to third parties, that is, at current market prices. The following tables provide components of segment profit for each segment for the three and nine months ended September 30, 2019 and 2018 (amounts in thousands): Three Months Ended September 30, 2019 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 150,225 $ — $ — $ 150,225 Intercompany rental revenue 23,242 — (23,242 ) — Observatory revenue — 37,575 — 37,575 Lease termination fees 2,361 — — 2,361 Third-party management and other fees 304 — — 304 Other revenue and fees 2,408 — — 2,408 Total revenues 178,540 37,575 (23,242 ) 192,873 Operating expenses: Property operating expenses 47,894 — — 47,894 Intercompany rent expense — 23,242 (23,242 ) — Ground rent expense 2,331 — — 2,331 General and administrative expenses 14,421 — — 14,421 Observatory expenses — 9,089 — 9,089 Real estate taxes 29,599 — — 29,599 Depreciation and amortization 44,253 7 — 44,260 Total operating expenses 138,498 32,338 (23,242 ) 147,594 Total operating income 40,042 5,237 — 45,279 Other income (expense): Interest income 2,269 — — 2,269 Interest expense (19,426 ) — — (19,426 ) Income before income taxes 22,885 5,237 — 28,122 Income tax expense (267 ) (1,071 ) — (1,338 ) Net income $ 22,618 $ 4,166 $ — $ 26,784 Segment assets $ 3,659,592 $ 265,725 $ — $ 3,925,317 Expenditures for segment assets $ 42,901 $ 18,375 $ — $ 61,276 Three Months Ended September 30, 2018 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 123,621 $ — $ — $ 123,621 Intercompany rental revenue 23,805 — (23,805 ) — Tenant expense reimbursement 18,627 — — 18,627 Observatory revenue — 40,241 — 40,241 Lease termination fees 1,185 — — 1,185 Third-party management and other fees 312 — — 312 Other revenue and fees 2,416 — — 2,416 Total revenues 169,966 40,241 (23,805 ) 186,402 Operating expenses: Property operating expenses 42,772 — — 42,772 Intercompany rent expense — 23,805 (23,805 ) — Ground rent expense 2,331 — — 2,331 General and administrative expenses 13,148 — — 13,148 Observatory expenses — 8,854 — 8,854 Real estate taxes 28,284 — — 28,284 Depreciation and amortization 42,458 17 — 42,475 Total operating expenses 128,993 32,676 (23,805 ) 137,864 Total operating income 40,973 7,565 — 48,538 Other income (expense): Interest income 3,485 — — 3,485 Interest expense (20,658 ) — — (20,658 ) Income before income taxes 23,800 7,565 — 31,365 Income tax expense (277 ) (1,858 ) — (2,135 ) Net income $ 23,523 $ 5,707 $ — $ 29,230 Segment assets $ 3,904,454 $ 262,378 $ — $ 4,166,832 Expenditures for segment assets $ 52,613 $ 14,507 $ — $ 67,120 Nine Months Ended September 30, 2019 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 434,713 $ — $ — $ 434,713 Intercompany rental revenue 58,754 — (58,754 ) — Observatory revenue — 91,039 — 91,039 Lease termination fees 3,112 — — 3,112 Third-party management and other fees 955 — — 955 Other revenue and fees 6,591 — — 6,591 Total revenues 504,125 91,039 (58,754 ) 536,410 Operating expenses: Property operating expenses 131,076 — — 131,076 Intercompany rent expense — 58,754 (58,754 ) — Ground rent expense 6,994 — — 6,994 General and administrative expenses 44,445 — — 44,445 Observatory expenses — 25,024 — 25,024 Real estate taxes 86,098 — — 86,098 Depreciation and amortization 135,157 22 — 135,179 Total operating expenses 403,770 83,800 (58,754 ) 428,816 Total operating income 100,355 7,239 — 107,594 Other income (expense): Interest income 9,907 — — 9,907 Interest expense (60,712 ) — — (60,712 ) Income before income taxes 49,550 7,239 — 56,789 Income tax expense (762 ) (457 ) — (1,219 ) Net income $ 48,788 $ 6,782 $ — $ 55,570 Expenditures for segment assets $ 134,865 $ 46,703 $ — $ 181,568 Nine Months Ended September 30, 2018 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 369,970 $ — $ — $ 369,970 Intercompany rental revenue 59,356 — (59,356 ) — Tenant expense reimbursement 52,626 — — 52,626 Observatory revenue — 96,691 — 96,691 Lease termination fees 2,164 — — 2,164 Third-party management and other fees 1,151 — — 1,151 Other revenue and fees 9,600 — — 9,600 Total revenues 494,867 96,691 (59,356 ) 532,202 Operating expenses: Property operating expenses 126,375 — — 126,375 Intercompany rent expense — 59,356 (59,356 ) — Ground rent expense 6,994 — — 6,994 General and administrative expenses 39,001 — — 39,001 Observatory expenses — 23,868 — 23,868 Real estate taxes 81,771 — — 81,771 Depreciation and amortization 121,775 51 — 121,826 Total operating expenses 375,916 83,275 (59,356 ) 399,835 Total operating income 118,951 13,416 — 132,367 Other income (expense): Interest income 7,209 — — 7,209 Interest expense (58,774 ) — — (58,774 ) Income before income taxes 67,386 13,416 — 80,802 Income tax expense (852 ) (2,478 ) — (3,330 ) Net income $ 66,534 $ 10,938 $ — $ 77,472 Expenditures for segment assets $ 148,429 $ 41,930 $ — $ 190,359

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events None.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Recently Issued or Adopted Accounting Standards	During August 2018, the FASB issued Accounting Standards Update ("ASU") No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force), which contain amendments that align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). Accordingly, for entities in a hosting arrangement that is a service contract, costs for implementation activities in the application development stage are capitalized depending on the nature of the costs, while costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. The amendments in ASU No. 2018-15 also require the entity (customer) to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement. The amendments are effective for public business entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption of the amendments is permitted, including adoption in any interim period. The amendments in ASU No. 2018-15 should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We are evaluating the impact of adopting this new accounting standard on our consolidated financial statements. During January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which contain amendments that modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. Because these amendments eliminate Step 2 from the goodwill impairment test, they should reduce the cost and complexity of evaluating goodwill for impairment. ASU No. 2017-04 should be applied on a prospective basis and the amendments adopted for the annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We are evaluating the impact of adopting this new accounting standard on our consolidated financial statements. During June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which contains amendments that replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU No. 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Earlier adoption as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, is permitted. The amendments must be adopted through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified retrospective approach). We do not anticipate the adoption of this new accounting standard to have a material impact on our consolidated financial statements. During February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires that a lessee recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. In addition, lessors may only capitalize incremental direct leasing costs. Subsequent amendments to ASU No. 2016-02 also provide lessors with a practical expedient, by class of underlying asset, to not separate nonlease components from the associated lease component provided that (1) the timing and pattern of transfer are the same for the nonlease components and associated lease component and (2) the lease component, if accounted separately, would be classified as an operating lease. We adopted this standard and related amendments on January 1, 2019 and elected the available practical expedients. Such adoption resulted in the recognition of right-of-use assets and lease liabilities for our operating leases on our balance sheet of approximately $29.5 million . We adopted FASB Topic 842, Lease Accounting, using the modified retrospective approach on January 1, 2019 and elected to apply the transition provisions of the standard at adoption. As such, the prior period amounts presented under Topic 840 were not restated to conform with the 2019 presentation. We adopted the practical expedient in Topic 842, which allows us to avoid separating lease and non-lease rental income. Consequently, all rental income earned pursuant to tenant leases in 2019 is reflected as one category, “Rental Revenue,” in the 2019 consolidated statement of income. Topic 842 also requires that a lessee recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The adoption of this standard resulted in the recognition of right-of-use assets and lease liabilities for our operating leases on our balance sheet of approximately $29.5 million . In addition, under Topic 842, lessors may only capitalize incremental direct leasing costs. As a result, we no longer capitalize our non-contingent leasing costs and instead expense these costs as incurred. These costs totaled $3.7 million
Basis of Quarterly Presentation	The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), for interim financial information, and with the rules and regulations of the Securities and Exchange Commission (the "SEC"). Accordingly, certain information and footnote disclosures required by GAAP for complete financial statements have been condensed or omitted in accordance with such rules and regulations. In the opinion of management, all adjustments and eliminations (including intercompany balances and transactions), consisting of normal recurring adjustments, considered necessary for the fair presentation of the financial statements have been included.
Principles of Consolidation	The results of operations for the periods presented are not necessarily indicative of the results that may be expected for the corresponding full years. These financial statements should be read in conjunction with the financial statements and accompanying notes included in the financial statements for the year ended December 31, 2018 contained in our Annual Report on Form 10-K. We do not consider our business to be subject to material seasonal fluctuations, except that our observatory business is subject to tourism seasonality.
Principles of Consolidation for Variable Interest Entities	We consolidate entities in which we have a controlling financial interest. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, authority to make decisions, and contractual and substantive participating rights of the partners/members. For variable interest entities ("VIE"), we consolidate the entity if we are deemed to have a variable interest in the entity and through that interest we are deemed the primary beneficiary. The primary beneficiary of a VIE 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. The primary beneficiary is required to consolidate the VIE. We had no VIEs as of September 30, 2019 and December 31, 2018. We will assess the accounting treatment for each investment we may have in the future. This assessment will include a review of each entity’s organizational agreement to determine which party has what rights and whether those rights are protective or participating. For all VIEs, we will review such agreements in order to determine which party has the power to direct the activities that most significantly impact the entity’s economic performance and benefit. In situations where we or our partner could approve, among other things, the annual budget, or leases that cover more than a nominal amount of space relative to the total rentable space at each property, we would not consolidate the investment as we consider these to be substantive participation rights that result in shared power of the activities that would most significantly impact the performance and benefit of such joint venture investment. A non-controlling interest in a consolidated subsidiary is defined as the portion of the equity (net assets) in a subsidiary not attributable, directly or indirectly, to a parent. Non-controlling interests are required to be presented as a separate component of equity in the condensed consolidated balance sheets and in the condensed consolidated statements of income by requiring earnings and other comprehensive income to be attributed to controlling and non-controlling interests.
Accounting Estimates	The preparation of the condensed consolidated financial statements in accordance with GAAP requires management to use estimates and assumptions that in certain circumstances affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported revenues and expenses. Significant items subject to such estimates and assumptions include allocation of the purchase price of acquired real estate properties among tangible and intangible assets, determination of the useful life of real estate properties and other long-lived assets, valuation and impairment analysis of commercial real estate properties, right of use assets and other long-lived assets, estimate of tenant expense reimbursements, valuation of the allowance for doubtful accounts, and valuation of derivative instruments, ground lease liabilities, senior unsecured notes, mortgage notes payable, unsecured term loan and revolving credit facilities, and equity based compensation. These estimates are prepared using management’s best judgment, after considering past, current, and expected events and economic conditions. Actual results could differ from those estimates.

Deferred Costs, Acquired Leas_2

Deferred Costs, Acquired Lease Intangibles and Goodwill (Tables)	9 Months Ended
	Sep. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs, Net	Deferred costs, net, consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Leasing costs $ 185,698 $ 178,120 Acquired in-place lease value and deferred leasing costs 206,026 214,550 Acquired above-market leases 49,906 52,136 441,630 444,806 Less: accumulated amortization (222,651 ) (209,839 ) Total deferred costs, net, excluding net deferred financing costs $ 218,979 $ 234,967 Deferred financing costs, net, consisted of the following at September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Financing costs $ 25,315 $ 25,315 Less: accumulated amortization (12,991 ) (10,027 ) Total deferred financing costs, net $ 12,324 $ 15,288
Amortizing Acquired Intangible Assets and Liabilities	Amortizing acquired intangible assets and liabilities consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Acquired below-market ground leases $ 396,916 $ 396,916 Less: accumulated amortization (42,392 ) (36,518 ) Acquired below-market ground leases, net $ 354,524 $ 360,398 September 30, 2019 December 31, 2018 Acquired below-market leases $ (113,625 ) $ (118,462 ) Less: accumulated amortization 70,970 66,012 Acquired below-market leases, net $ (42,655 ) $ (52,450 )

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	Debt consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): Principal Balance As of September 30, 2019 September 30, 2019 December 31, 2018 Stated Effective (1) Maturity (2) Mortgage debt collateralized by: Fixed rate mortgage debt Metro Center $ 90,205 $ 91,838 3.59 % 3.67 % 11/5/2024 10 Union Square 50,000 50,000 3.70 % 3.97 % 4/1/2026 1542 Third Avenue 30,000 30,000 4.29 % 4.53 % 5/1/2027 First Stamford Place (3) 180,000 180,000 4.28 % 4.44 % 7/1/2027 1010 Third Avenue and 77 West 55th Street 38,440 38,995 4.01 % 4.21 % 1/5/2028 10 Bank Street 33,138 33,779 4.23 % 4.36 % 6/1/2032 383 Main Avenue 30,000 30,000 4.44 % 4.55 % 6/30/2032 1333 Broadway 160,000 160,000 4.21 % 4.29 % 2/5/2033 Total mortgage debt 611,783 614,612 Senior unsecured notes - exchangeable — 250,000 — — — Senior unsecured notes: (6) Series A 100,000 100,000 3.93 % 3.96 % 3/27/2025 Series B 125,000 125,000 4.09 % 4.12 % 3/27/2027 Series C 125,000 125,000 4.18 % 4.21 % 3/27/2030 Series D 115,000 115,000 4.08 % 4.11 % 1/22/2028 Series E 160,000 160,000 4.26 % 4.27 % 3/22/2030 Series F 175,000 175,000 4.44 % 4.45 % 3/22/2033 Unsecured revolving credit facility (6) — — (4) (4) 8/29/2021 Unsecured term loan facility (6) 265,000 265,000 (5) (5) 8/29/2022 Total principal 1,676,783 1,929,612 Unamortized discount, net of unamortized premium — (1,647 ) Deferred financing costs, net (7,606 ) (9,032 ) Total $ 1,669,177 $ 1,918,933 ______________ (1) The effective rate is the yield as of September 30, 2019 , including the effects of debt issuance costs and the amortization of the fair value of debt adjustment. (2) Pre-payment is generally allowed for each loan upon payment of a customary pre-payment penalty. (3) Represents a $164 million mortgage loan bearing interest at 4.09% and a $16 million loan bearing interest at 6.25% . (4) At September 30, 2019 , the unsecured revolving credit facility bears a floating rate at 30 day LIBOR plus 1.10% . The rate at September 30, 2019 was 3.12% . (5) The unsecured term loan facility bears a floating rate at 30 day LIBOR plus 1.20% . Pursuant to an interest rate swap agreement, the LIBOR rate is fixed at 2.1485% through maturity. The rate at September 30, 2019 was 3.35% . (6) At September 30, 2019 , we were in compliance with all debt covenants.
Aggregate Required Principal Payments	Aggregate required principal payments at September 30, 2019 are as follows (amounts in thousands): Year Amortization Maturities Total 2019 $ 961 $ — $ 961 2020 3,938 — 3,938 2021 4,090 — 4,090 2022 5,628 265,000 270,628 2023 7,876 — 7,876 Thereafter 33,868 1,355,422 1,389,290 Total $ 56,361 $ 1,620,422 $ 1,676,783
Deferred Costs, Net	Deferred costs, net, consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Leasing costs $ 185,698 $ 178,120 Acquired in-place lease value and deferred leasing costs 206,026 214,550 Acquired above-market leases 49,906 52,136 441,630 444,806 Less: accumulated amortization (222,651 ) (209,839 ) Total deferred costs, net, excluding net deferred financing costs $ 218,979 $ 234,967 Deferred financing costs, net, consisted of the following at September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Financing costs $ 25,315 $ 25,315 Less: accumulated amortization (12,991 ) (10,027 ) Total deferred financing costs, net $ 12,324 $ 15,288

Accounts Payable and Accrued _2

Accounts Payable and Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Payables and Accruals [Abstract]
Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses consisted of the following as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 December 31, 2018 Accrued capital expenditures $ 77,142 $ 85,242 Accounts payable and accrued expenses 34,328 34,585 Interest rate swap agreements liability 28,850 5,243 Accrued interest payable 2,851 4,990 Due to affiliated companies 30 616 Total accounts payable and accrued expenses $ 143,201 $ 130,676

Financial Instruments and Fai_2

Financial Instruments and Fair Values (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Summary of the Terms of Agreements and the Fair Value of Derivative Financial Instruments	The table below summarizes the terms of agreements and the fair values of our derivative financial instruments as of September 30, 2019 and December 31, 2018 (dollar amounts in thousands): September 30, 2019 December 31, 2018 Derivative Notional Amount Receive Rate Pay Rate Effective Date Expiration Date Asset Liability Asset Liability Interest rate swap $ 265,000 1 Month LIBOR 2.1485% August 31, 2017 August 24, 2022 $ — $ (5,594 ) $ 2,536 $ — Interest rate swap 125,000 3 Month LIBOR 2.9580% July 1, 2019 July 1, 2026 — (11,628 ) — (2,623 ) Interest rate swap 125,000 3 Month LIBOR 2.9580% July 1, 2019 July 1, 2026 — (11,628 ) — (2,620 ) $ — $ (28,850 ) $ 2,536 $ (5,243 )
Effect of Derivative Financial Instruments Designated as Cash Flow Hedges	The table below shows the effect of our derivative financial instruments designated as cash flow hedges on accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2019 and 2018 (amounts in thousands): Three Months Ended Nine Months Ended Effects of Cash Flow Hedges September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Amount of gain (loss) recognized in other comprehensive income (loss) $ (6,256 ) $ 3,884 $ (25,992 ) $ 9,827 Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense (319 ) (427 ) (637 ) (1,562 ) The table below shows the effect of our derivative financial instruments designated as cash flow hedges on the condensed consolidated statements of income for the three and nine months ended September 30, 2019 and 2018 (amounts in thousands): Three Months Ended Nine Months Ended Effects of Cash Flow Hedges September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Total interest (expense) presented in the condensed consolidated statements of income in which the effects of cash flow hedges are recorded $ (19,426 ) $ (20,658 ) $ (60,712 ) $ (58,774 ) Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense (319 ) (427 ) (637 ) (1,562 )
Summary of the Carrying and Estimated Fair Values of Financial Instruments	The following tables summarize the carrying and estimated fair values of our financial instruments as of September 30, 2019 and December 31, 2018 (amounts in thousands): September 30, 2019 Estimated Fair Value Carrying Total Level 1 Level 2 Level 3 Interest rate swaps included in prepaid expenses and other assets $ — $ — $ — $ — $ — Interest rate swaps included in accounts payable and accrued expenses 28,850 28,850 — 28,850 — Mortgage notes payable 606,313 643,159 — — 643,159 Senior unsecured notes - Series A, B, C, D, E and F 798,347 861,245 — — 861,245 Unsecured term loan facility 264,517 265,000 — — 265,000 Ground lease liabilities 29,355 29,355 — — 29,355 December 31, 2018 Estimated Fair Value Carrying Total Level 1 Level 2 Level 3 Interest rate swaps included in prepaid expenses and other assets $ 2,536 $ 2,536 $ — $ 2,536 $ — Interest rate swaps included in accounts payable and accrued expenses 5,243 5,243 — 5,243 — Mortgage notes payable 608,567 597,424 — — 597,424 Senior unsecured notes - Exchangeable 247,930 250,625 — 250,625 — Senior unsecured notes - Series A, B, C, D, E and F 798,289 795,662 — — 795,662 Unsecured term loan facility 264,147 265,000 — — 265,000

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Schedule of Components of Rental Revenue	The components of rental revenue for the three and nine months ended September 30, 2019 are as follows (amounts in thousands): Three months ended September 30, 2019 Nine months ended September 30, 2019 Fixed payments $ 129,030 $ 380,647 Variable payments 21,195 54,066 Total rental revenue $ 150,225 $ 434,713
Schedule of Future Contractual Minimum Lease Payments On Non-Cancellable Operating Leases To Be Received	As of September 30, 2019, we were entitled to the following future contractual minimum lease payments (excluding operating expense reimbursements) on non-cancellable operating leases to be received which expire on various dates through 2038 (amounts in thousands): Remainder of 2019 $ 124,080 2020 496,805 2021 477,068 2022 446,300 2023 419,857 Thereafter 1,954,810 $ 3,918,920
Schedule of Future Contractual Minimum Lease Payments On Non-Cancellable Operating Leases To Be Received	Future minimum lease payments to be paid over the terms of the leases as of December 31, 2018 are as follows (amounts in thousands): 2019 $ 1,518 2020 1,518 2021 1,518 2022 1,518 2023 1,518 Thereafter 68,298 $ 75,888 As of December 31, 2018, we were entitled to the following future contractual minimum lease payments (excluding operating expense reimbursements) on non-cancellable operating leases to be received which expire on various dates through 2038 (amounts in thousands): 2019 $ 485,441 2020 460,127 2021 423,365 2022 391,395 2023 362,738 Thereafter 1,536,461 $ 3,659,527
Schedule of Information Relating to the Measurement of Lease Liabilities	Information relating to the measurement of our lease liabilities as of September 30, 2019 are as follows: Weighted average remaining lease term (in years) 50.8 Weighted average discount rate 4.49 % Cash paid for operating leases nine months ended September 30, 2019 (in thousands) $ 1,139
Schedule of Future Minimum Lease Payments	Future minimum lease payments to be paid over the terms of the leases as of September 30, 2019 are as follows (amounts in thousands): Remainder of 2019 $ 380 2020 1,518 2021 1,518 2022 1,518 2023 1,518 Thereafter 68,298 Total undiscounted cash flows 74,750 Present value discount (45,395 ) Ground lease liabilities $ 29,355

Capital (Tables)

Capital (Tables)	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note Disclosure, Disclosure of Compensation Related Costs, Share-based Payments and Earnings Per Share [Abstract]
Summary of ERST Restricted Stock and LTIP Unit	The following is a summary of ESRT restricted stock and LTIP unit activity for the nine months ended September 30, 2019 : Restricted Stock LTIP Units Weighted Average Grant Fair Value Unvested balance at December 31, 2018 91,158 5,702,821 $ 9.68 Vested (35,724 ) (598,402 ) 15.98 Granted 69,358 2,848,726 9.55 Forfeited or unearned (5,762 ) (1,972,548 ) 7.34 Unvested balance at September 30, 2019 119,030 5,980,597 $ 9.72
Earnings Per Unit	Earnings per unit for the three and nine months ended September 30, 2019 and 2018 is computed as follows (amounts in thousands, except per share amounts): Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Numerator: Net income $ 26,784 $ 29,230 $ 55,570 $ 77,472 Private perpetual preferred unit distributions (234 ) (234 ) (702 ) (702 ) Earnings allocated to unvested units (243 ) (212 ) (646 ) (586 ) Net income attributable to common unitholders - basic and diluted $ 26,307 $ 28,784 $ 54,222 $ 76,184 Denominator: Weighted average units outstanding - basic 298,151 297,478 298,117 297,180 Effect of dilutive securities: Stock-based compensation plans — — — 1 Weighted average units outstanding - diluted 298,151 297,478 298,117 297,181 Earnings per share: Basic $ 0.09 $ 0.10 $ 0.18 $ 0.26 Diluted $ 0.09 $ 0.10 $ 0.18 $ 0.26

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Components of Segment Profit for Each Segment	The following tables provide components of segment profit for each segment for the three and nine months ended September 30, 2019 and 2018 (amounts in thousands): Three Months Ended September 30, 2019 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 150,225 $ — $ — $ 150,225 Intercompany rental revenue 23,242 — (23,242 ) — Observatory revenue — 37,575 — 37,575 Lease termination fees 2,361 — — 2,361 Third-party management and other fees 304 — — 304 Other revenue and fees 2,408 — — 2,408 Total revenues 178,540 37,575 (23,242 ) 192,873 Operating expenses: Property operating expenses 47,894 — — 47,894 Intercompany rent expense — 23,242 (23,242 ) — Ground rent expense 2,331 — — 2,331 General and administrative expenses 14,421 — — 14,421 Observatory expenses — 9,089 — 9,089 Real estate taxes 29,599 — — 29,599 Depreciation and amortization 44,253 7 — 44,260 Total operating expenses 138,498 32,338 (23,242 ) 147,594 Total operating income 40,042 5,237 — 45,279 Other income (expense): Interest income 2,269 — — 2,269 Interest expense (19,426 ) — — (19,426 ) Income before income taxes 22,885 5,237 — 28,122 Income tax expense (267 ) (1,071 ) — (1,338 ) Net income $ 22,618 $ 4,166 $ — $ 26,784 Segment assets $ 3,659,592 $ 265,725 $ — $ 3,925,317 Expenditures for segment assets $ 42,901 $ 18,375 $ — $ 61,276 Three Months Ended September 30, 2018 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 123,621 $ — $ — $ 123,621 Intercompany rental revenue 23,805 — (23,805 ) — Tenant expense reimbursement 18,627 — — 18,627 Observatory revenue — 40,241 — 40,241 Lease termination fees 1,185 — — 1,185 Third-party management and other fees 312 — — 312 Other revenue and fees 2,416 — — 2,416 Total revenues 169,966 40,241 (23,805 ) 186,402 Operating expenses: Property operating expenses 42,772 — — 42,772 Intercompany rent expense — 23,805 (23,805 ) — Ground rent expense 2,331 — — 2,331 General and administrative expenses 13,148 — — 13,148 Observatory expenses — 8,854 — 8,854 Real estate taxes 28,284 — — 28,284 Depreciation and amortization 42,458 17 — 42,475 Total operating expenses 128,993 32,676 (23,805 ) 137,864 Total operating income 40,973 7,565 — 48,538 Other income (expense): Interest income 3,485 — — 3,485 Interest expense (20,658 ) — — (20,658 ) Income before income taxes 23,800 7,565 — 31,365 Income tax expense (277 ) (1,858 ) — (2,135 ) Net income $ 23,523 $ 5,707 $ — $ 29,230 Segment assets $ 3,904,454 $ 262,378 $ — $ 4,166,832 Expenditures for segment assets $ 52,613 $ 14,507 $ — $ 67,120 Nine Months Ended September 30, 2019 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 434,713 $ — $ — $ 434,713 Intercompany rental revenue 58,754 — (58,754 ) — Observatory revenue — 91,039 — 91,039 Lease termination fees 3,112 — — 3,112 Third-party management and other fees 955 — — 955 Other revenue and fees 6,591 — — 6,591 Total revenues 504,125 91,039 (58,754 ) 536,410 Operating expenses: Property operating expenses 131,076 — — 131,076 Intercompany rent expense — 58,754 (58,754 ) — Ground rent expense 6,994 — — 6,994 General and administrative expenses 44,445 — — 44,445 Observatory expenses — 25,024 — 25,024 Real estate taxes 86,098 — — 86,098 Depreciation and amortization 135,157 22 — 135,179 Total operating expenses 403,770 83,800 (58,754 ) 428,816 Total operating income 100,355 7,239 — 107,594 Other income (expense): Interest income 9,907 — — 9,907 Interest expense (60,712 ) — — (60,712 ) Income before income taxes 49,550 7,239 — 56,789 Income tax expense (762 ) (457 ) — (1,219 ) Net income $ 48,788 $ 6,782 $ — $ 55,570 Expenditures for segment assets $ 134,865 $ 46,703 $ — $ 181,568 Nine Months Ended September 30, 2018 Real Estate Observatory Intersegment Elimination Total Revenues: Rental revenue $ 369,970 $ — $ — $ 369,970 Intercompany rental revenue 59,356 — (59,356 ) — Tenant expense reimbursement 52,626 — — 52,626 Observatory revenue — 96,691 — 96,691 Lease termination fees 2,164 — — 2,164 Third-party management and other fees 1,151 — — 1,151 Other revenue and fees 9,600 — — 9,600 Total revenues 494,867 96,691 (59,356 ) 532,202 Operating expenses: Property operating expenses 126,375 — — 126,375 Intercompany rent expense — 59,356 (59,356 ) — Ground rent expense 6,994 — — 6,994 General and administrative expenses 39,001 — — 39,001 Observatory expenses — 23,868 — 23,868 Real estate taxes 81,771 — — 81,771 Depreciation and amortization 121,775 51 — 121,826 Total operating expenses 375,916 83,275 (59,356 ) 399,835 Total operating income 118,951 13,416 — 132,367 Other income (expense): Interest income 7,209 — — 7,209 Interest expense (58,774 ) — — (58,774 ) Income before income taxes 67,386 13,416 — 80,802 Income tax expense (852 ) (2,478 ) — (3,330 ) Net income $ 66,534 $ 10,938 $ — $ 77,472 Expenditures for segment assets $ 148,429 $ 41,930 $ — $ 190,359

Description of Business and O_2

Description of Business and Organization (Details)	Sep. 30, 2019ft²parceloffice_and_property
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	10,100,000
Office Building
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	9,400,000
Number of properties | office_and_property	14
Office Building | Manhattan
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	7,600,000
Number of properties | office_and_property	9
Office Building | Fairfield County, Connecticut and Westchester County, New York
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	1,800,000
Number of properties | office_and_property	5
Development Parcel
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties | parcel	3
Retail Site | Manhattan and Westport, Connecticut
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	205,595
Retail Site | Manhattan
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	511,755
Number of properties | office_and_property	4
Retail Site | Westport, Connecticut
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties | office_and_property	2
Other Property | Stamford, Connecticut
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property (in square feet)	380,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Jan. 01, 2019
Accounting Policies [Line Items]
Operating lease, right-of-use assets	$ 29,355
Operating lease, liabilities	29,355
Leasing cost	$ 3,700
Minimum
Accounting Policies [Line Items]
Observatory revenue realized during the first quarter, previous ten years (as a percent)	16.00%
Observatory revenue realized during the second quarter, previous ten years (as a percent)	26.00%
Observatory revenue realized during the third quarter, previous ten years (as a percent)	31.00%
Observatory revenue realized during the fourth quarter, previous ten years (as a percent)	23.00%
Maximum
Accounting Policies [Line Items]
Observatory revenue realized during the first quarter, previous ten years (as a percent)	18.00%
Observatory revenue realized during the second quarter, previous ten years (as a percent)	28.00%
Observatory revenue realized during the third quarter, previous ten years (as a percent)	33.00%
Observatory revenue realized during the fourth quarter, previous ten years (as a percent)	25.00%
ASU 2016-02
Accounting Policies [Line Items]
Operating lease, right-of-use assets		$ 29,500
Operating lease, liabilities		$ 29,500

Deferred Costs, Acquired Leas_3

Deferred Costs, Acquired Lease Intangibles and Goodwill - Deferred Costs, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Leasing costs	$ 185,698	$ 178,120
Deferred costs, gross	441,630	444,806
Less: accumulated amortization	(222,651)	(209,839)
Total deferred costs, net, excluding net deferred financing costs	218,979	234,967
Acquired in-place lease value and deferred leasing costs
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	206,026	214,550
Acquired above-market leases
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	$ 49,906	$ 52,136

Deferred Costs, Acquired Leas_4

Deferred Costs, Acquired Lease Intangibles and Goodwill - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Deferred Costs [Line Items]
Amortization expense related to deferred leasing costs	$ 6,200		$ 18,300
Amortization expense related to deferred leasing costs		$ 6,300		$ 18,400
Rental revenue related to amortization of below-market leases, net of above-market leases	1,700	1,700	5,780	4,387
Goodwill	491,479		491,479		$ 491,479
Lease agreements
Deferred Costs [Line Items]
Amortization expense related to acquired lease intangibles	2,400	$ 2,900	8,200	$ 9,300
Observatory
Deferred Costs [Line Items]
Goodwill	227,500		227,500
Real estate
Deferred Costs [Line Items]
Goodwill	264,000		264,000
Revolving credit facility | Unsecured revolving credit facility
Deferred Costs [Line Items]
Net deferred financing costs	$ 4,700		$ 4,700		$ 6,300

Deferred Costs, Acquired Leas_5

Deferred Costs, Acquired Lease Intangibles and Goodwill - Amortizing Acquired Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Acquired below-market ground leases
Acquired below-market ground leases, gross	$ 396,916	$ 396,916
Less: accumulated amortization	(42,392)	(36,518)
Acquired below-market ground leases, net	354,524	360,398
Acquired below-market leases
Acquired below-market leases, gross	(113,625)	(118,462)
Less: accumulated amortization	70,970	66,012
Acquired below-market leases, net	$ (42,655)	$ (52,450)

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Aug. 31, 2014
Debt Instrument [Line Items]
Total	$ 606,313,000	$ 608,567,000
Unsecured facility	0	0
Deferred financing costs, net	(12,324,000)	(15,288,000)
Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	611,783,000	614,612,000
Total	1,669,177,000	1,918,933,000
Total principal	1,676,783,000	1,929,612,000
Unamortized discount, net of unamortized premium	0	(1,647,000)
Deferred financing costs, net	(7,606,000)	(9,032,000)
Metro Center | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 90,205,000	91,838,000
Stated rate (as a percent)	3.59%
Effective Rate (as a percentage)	3.67%
10 Union Square | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 50,000,000	50,000,000
Stated rate (as a percent)	3.70%
Effective Rate (as a percentage)	3.97%
1542 Third Avenue | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 30,000,000	30,000,000
Stated rate (as a percent)	4.29%
Effective Rate (as a percentage)	4.53%
First Stamford Place | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 180,000,000	180,000,000
Stated rate (as a percent)	4.28%
Effective Rate (as a percentage)	4.44%
First Stamford Place - First Lien | Mortgages
Debt Instrument [Line Items]
Face amount	$ 164,000,000
Stated rate (as a percent)	4.09%
First Stamford Place - Second Lien | Mortgages
Debt Instrument [Line Items]
Face amount	$ 16,000,000
Stated rate (as a percent)	6.25%
1010 Third Avenue and 77 West 55th Street | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 38,440,000	38,995,000
Stated rate (as a percent)	4.01%
Effective Rate (as a percentage)	4.21%
10 Bank Street | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 33,138,000	33,779,000
Stated rate (as a percent)	4.23%
Effective Rate (as a percentage)	4.36%
383 Main Avenue | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 30,000,000	30,000,000
Stated rate (as a percent)	4.44%
Effective Rate (as a percentage)	4.55%
1333 Broadway | Mortgages
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 160,000,000	160,000,000
Stated rate (as a percent)	4.21%
Effective Rate (as a percentage)	4.29%
Senior unsecured notes - exchangeable | Convertible debt
Debt Instrument [Line Items]
Fixed rate mortgage debt	$ 0	250,000,000
Face amount			$ 250,000,000
Stated rate (as a percent)	0.00%		2.625%
Effective Rate (as a percentage)	0.00%
Senior unsecured notes, Series A | Senior notes
Debt Instrument [Line Items]
Total	$ 100,000,000	100,000,000
Stated rate (as a percent)	3.93%
Effective Rate (as a percentage)	3.96%
Senior unsecured notes, Series B | Senior notes
Debt Instrument [Line Items]
Total	$ 125,000,000	125,000,000
Stated rate (as a percent)	4.09%
Effective Rate (as a percentage)	4.12%
Senior unsecured notes, Series C | Senior notes
Debt Instrument [Line Items]
Total	$ 125,000,000	125,000,000
Stated rate (as a percent)	4.18%
Effective Rate (as a percentage)	4.21%
Senior unsecured notes, Series D | Senior notes
Debt Instrument [Line Items]
Total	$ 115,000,000	115,000,000
Stated rate (as a percent)	4.08%
Effective Rate (as a percentage)	4.11%
Senior unsecured notes, Series E | Senior notes
Debt Instrument [Line Items]
Total	$ 160,000,000	160,000,000
Stated rate (as a percent)	4.26%
Effective Rate (as a percentage)	4.27%
Senior unsecured notes, Series F | Senior notes
Debt Instrument [Line Items]
Total	$ 175,000,000	175,000,000
Stated rate (as a percent)	4.44%
Effective Rate (as a percentage)	4.45%
Unsecured revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Unsecured facility	$ 0	0
Effective Rate (as a percentage)	3.12%
Unsecured revolving credit facility | Revolving credit facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percentage)	1.10%
Unsecured term loan facility | Revolving credit facility
Debt Instrument [Line Items]
Unsecured facility	$ 265,000,000	$ 265,000,000
Stated rate (as a percent)	3.35%
Pay rate (as a percent)	2.1485%
Unsecured term loan facility | Revolving credit facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percentage)	1.20%

Debt - Aggregate Required Princ

Debt - Aggregate Required Principal Payments (Details) - Mortgages - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Amortization
2019	$ 961
2020	3,938
2021	4,090
2022	5,628
2023	7,876
Thereafter	33,868
Total	56,361
Maturities
2019	0
2020	0
2021	0
2022	265,000
2023	0
Thereafter	1,355,422
Total	1,620,422
Total
2019	961
2020	3,938
2021	4,090
2022	270,628
2023	7,876
Thereafter	1,389,290
Total	$ 1,676,783	$ 1,929,612

Debt - Deferred Financing Costs

Debt - Deferred Financing Costs, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Financing costs	$ 25,315		$ 25,315		$ 25,315
Less: accumulated amortization	(12,991)		(12,991)		(10,027)
Total deferred financing costs, net	12,324		12,324		15,288
Amortization expense related to deferred financing costs	900	$ 1,100	2,900	$ 3,100
Revolving credit facility | Unsecured revolving credit facility
Debt Instrument [Line Items]
Net deferred financing costs	$ 4,700		$ 4,700		$ 6,300

Debt - Unsecured Revolving Cred

Debt - Unsecured Revolving Credit and Term Loan Facility (Details) - Revolving Credit Facility	1 Months Ended
	Aug. 31, 2017USD ($)option
Unsecured Revolving Credit Facility and Term Loan
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 1,365,000,000
Unsecured revolving credit facility, higher borrowing capacity option	1,750,000,000
Unsecured revolving credit facility
Line of Credit Facility [Line Items]
Current borrowing capacity	$ 1,100,000,000
Number of options to extend maturity | option	2
Extension period (in months)	6 months
Unsecured term loan facility
Line of Credit Facility [Line Items]
Current borrowing capacity	$ 265,000,000
Minimum | Unsecured revolving credit facility
Line of Credit Facility [Line Items]
Extension fee, as a percent of outstanding commitments under revolving credit facility (percentage)	0.0625%
Maximum | Unsecured revolving credit facility
Line of Credit Facility [Line Items]
Extension fee, as a percent of outstanding commitments under revolving credit facility (percentage)	0.075%

Debt - Exchangeable Senior Note

Debt - Exchangeable Senior Notes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Aug. 31, 2014
Debt Instrument [Line Items]
Amortization of deferred financing costs	$ 900,000	$ 1,100,000	$ 2,900,000	$ 3,100,000
Convertible debt | Exchangeable Senior Notes due August 15, 2019
Debt Instrument [Line Items]
Face amount					$ 250,000,000
Stated rate (as a percent)	0.00%		0.00%		2.625%
Debt interest expense	$ 1,200,000	2,400,000	$ 6,100,000	7,300,000
Contractual interest expense	800,000	1,600,000	4,100,000	4,900,000
Additional non-cash interest expense	300,000	700,000	1,600,000	2,000,000
Amortization of deferred financing costs	$ 100,000	$ 100,000	$ 400,000	$ 400,000

Accounts Payable and Accrued _3

Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued capital expenditures	$ 77,142	$ 85,242
Accounts payable and accrued expenses	34,328	34,585
Interest rate swap agreements liability	28,850	5,243
Accrued interest payable	2,851	4,990
Due to affiliated companies	30	616
Total accounts payable and accrued expenses	$ 143,201	$ 130,676

Financial Instruments and Fai_3

Financial Instruments and Fair Values - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements liability	$ 28,850,000		$ 28,850,000		$ 5,243,000
Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements liability	29,300,000		29,300,000
Designated as Hedging Instrument | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loss to be reclassified into interest expense within the next 12 months			(5,600,000)
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate notional value	515,000,000		515,000,000		515,000,000
Net unrealized gain (loss)	(5,900,000)	$ 4,300,000	(25,400,000)	$ 11,400,000
Accounts payable and accrued expenses | Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements liability	$ 28,800,000		$ 28,800,000		5,200,000
Prepaid expenses and other assets | Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements asset					$ 2,500,000

Financial Instruments and Fai_4

Financial Instruments and Fair Values - Summary of the Terms of Agreements and the Fair Value of Derivative Financial Instruments (Details) - Cash Flow Hedging - Designated as Hedging Instrument - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset	$ 0	$ 2,536,000
Liability	(28,850,000)	(5,243,000)
LIBOR | Interest Rate Swap, One Month LIBOR, 2.1485%
Derivatives, Fair Value [Line Items]
Notional Amount	$ 265,000,000
Pay Rate	2.1485%
Asset	$ 0	2,536,000
Liability	(5,594,000)	0
LIBOR | Interest Rate Swap, Three Month LIBOR, 2.9580%, Swap 1
Derivatives, Fair Value [Line Items]
Notional Amount	$ 125,000,000
Pay Rate	2.958%
Asset	$ 0	0
Liability	(11,628,000)	(2,623,000)
LIBOR | Interest Rate Swap, Three Month LIBOR, 2.9580%, Swap 2
Derivatives, Fair Value [Line Items]
Notional Amount	$ 125,000,000
Pay Rate	2.958%
Asset	$ 0	0
Liability	$ (11,628,000)	$ (2,620,000)

Financial Instruments and Fai_5

Financial Instruments and Fair Values - Effect of Derivative Financial Instruments Designated as Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss)	$ (6,256)	$ 3,884	$ (25,992)	$ 9,827
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense	(319)	(427)	(637)	(1,562)
Interest expense	(19,426)	(20,658)	(60,712)	(58,774)
Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss)	(6,256)	3,884	(25,992)	9,827
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense	(319)	(427)	(637)	(1,562)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated other comprehensive income (loss) | Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	$ (319)	$ (427)	$ (637)	$ (1,562)

Financial Instruments and Fai_6

Financial Instruments and Fair Values - Summary of the Carrying and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	$ 28,850	$ 5,243
Ground lease liabilities	29,355
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Ground lease liabilities	29,355
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Ground lease liabilities	29,355
Mortgages | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	606,313	608,567
Mortgages | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	643,159	597,424
Senior unsecured notes - Exchangeable | Exchangeable notes | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		247,930
Senior unsecured notes - Exchangeable | Exchangeable notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		250,625
Senior unsecured notes - Series A, B, C, D, E and F | Senior notes | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	798,347	798,289
Senior unsecured notes - Series A, B, C, D, E and F | Senior notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	861,245	795,662
Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Ground lease liabilities	0
Fair Value, Inputs, Level 1 | Mortgages | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Fair Value, Inputs, Level 1 | Senior unsecured notes - Exchangeable | Exchangeable notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		0
Fair Value, Inputs, Level 1 | Senior unsecured notes - Series A, B, C, D, E and F | Senior notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Fair Value, Inputs, Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Ground lease liabilities	0
Fair Value, Inputs, Level 2 | Mortgages | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Fair Value, Inputs, Level 2 | Senior unsecured notes - Exchangeable | Exchangeable notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		250,625
Fair Value, Inputs, Level 2 | Senior unsecured notes - Series A, B, C, D, E and F | Senior notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Fair Value, Inputs, Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Ground lease liabilities	29,355
Fair Value, Inputs, Level 3 | Mortgages | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	643,159	597,424
Fair Value, Inputs, Level 3 | Senior unsecured notes - Exchangeable | Exchangeable notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		0
Fair Value, Inputs, Level 3 | Senior unsecured notes - Series A, B, C, D, E and F | Senior notes | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	861,245	795,662
Revolving Credit Facility | Unsecured term loan facility | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	264,517	264,147
Revolving Credit Facility | Unsecured term loan facility | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	265,000	265,000
Revolving Credit Facility | Fair Value, Inputs, Level 1 | Unsecured term loan facility | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Revolving Credit Facility | Fair Value, Inputs, Level 2 | Unsecured term loan facility | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Revolving Credit Facility | Fair Value, Inputs, Level 3 | Unsecured term loan facility | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	265,000	265,000
Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	29,300
Interest Rate Swap | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	2,536
Interest rate swaps included in accounts payable and accrued expenses	28,850	5,243
Interest Rate Swap | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	2,536
Interest rate swaps included in accounts payable and accrued expenses	28,850	5,243
Interest Rate Swap | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	0
Interest rate swaps included in accounts payable and accrued expenses	0	0
Interest Rate Swap | Fair Value, Inputs, Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	2,536
Interest rate swaps included in accounts payable and accrued expenses	28,850	5,243
Interest Rate Swap | Fair Value, Inputs, Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	0
Interest rate swaps included in accounts payable and accrued expenses	$ 0	$ 0

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands	Sep. 30, 2019USD ($)property
Operating Leases [Line Items]
Number of properties subject to ground leases | property	3
Right-of-use assets	$ 29,355
Lease liabilities	$ 29,355
Minimum
Operating Leases [Line Items]
Term of lease	1 year
Maximum
Operating Leases [Line Items]
Term of lease	21 years

Leases - Components of Rental R

Leases - Components of Rental Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Fixed payments	$ 129,030	$ 380,647
Variable payments	21,195	54,066
Total rental revenue	$ 150,225	$ 434,713

Leases - Future Contractual Min

Leases - Future Contractual Minimum Lease Payments On Non-Cancellable Operating Leases To Be Received (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Remainder of 2019	$ 124,080
2020	496,805
2021	477,068
2022	446,300
2023	419,857
Thereafter	1,954,810
Total future minimum lease payments on non-cancellable operating leases to be received	$ 3,918,920
2019		$ 485,441
2020		460,127
2021		423,365
2022		391,395
2023		362,738
Thereafter		1,536,461
Total future minimum lease payments on non-cancellable operating leases to be received		$ 3,659,527

Leases - Information Relating t

Leases - Information Relating to the Measurement of Lease Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Leases [Abstract]
Weighted average remaining lease term (in years)	50 years 9 months 18 days
Weighted average discount rate	4.49%
Cash paid for operating leases nine months ended September 30, 2019 (in thousands)	$ 1,139

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments on Ground Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Remainder of 2019	$ 380
2020	1,518
2021	1,518
2022	1,518
2023	1,518
Thereafter	68,298
Total undiscounted cash flows	74,750
Present value discount	(45,395)
Ground lease liabilities	$ 29,355
2019		$ 1,518
2020		1,518
2021		1,518
2022		1,518
2023		1,518
Thereafter		68,298
Total future minimum lease payments		$ 75,888

Commitments and Contingencies

Commitments and Contingencies - Legal Proceedings (Details)	1 Months Ended
	Oct. 31, 2014participant
New York State Supreme Court, New York County
Loss Contingencies [Line Items]
Number of participants opting out of settlement	12

Commitments and Contingencies_2

Commitments and Contingencies - Unfunded Capital Expenditures (Details) $ in Millions	Sep. 30, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Estimated capital expenditures to be incurred	$ 144.2

Capital - Additional Informatio

Capital - Additional Information and Private Perpetual Preferred Units (Details) - $ / shares	9 Months Ended
	Sep. 30, 2019	May 16, 2019
Shares and Units [Abstract]
OP units outstanding (in shares)	304,256,572
Dividends on common stock received until performance criteria met for LTIP units (as a percent)	10.00%
Dividends on common stock received after performance criteria met for LTIP units (as a percent)	90.00%
Dividends on common stock received in periods after performance criteria met for LTIP units (as a percent)	100.00%
2019 Plan
Shares and Units [Abstract]
Number of shares authorized under the plan (in shares)	11,000,000	11,000,000
Private Perpetual Preferred Units
Shares and Units [Abstract]
Maximum number of shares offered in exchange (in shares)	15,000,000
Liquidation preference (in USD per share)	$ 13.52
Cumulative preferential annual cash distributions per unit (in USD per share)	$ 0.70
Percentage of liquidation preference	200.00%
Empire State Realty Trust
Shares and Units [Abstract]
OP units owned by the Company (in shares)	180,149,553
Other Partners, Certain Directors, Officers And Other Members Of Executive Management
Shares and Units [Abstract]
OP units not owned by the Company (in shares)	124,107,019
Empire State Realty OP | Empire State Realty Trust
Shares and Units [Abstract]
OP units owned by the Company (as a percent)	59.20%
Empire State Realty OP | Other Partners, Certain Directors, Officers And Other Members Of Executive Management
Shares and Units [Abstract]
OP units not owned by the Company (as a percent)	40.80%

Capital - Distributions (Detail

Capital - Distributions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stockholders' Equity Note Disclosure, Disclosure of Compensation Related Costs, Share-based Payments and Earnings Per Share [Abstract]
Distributions paid to OP unitholders	$ 31.9	$ 31.9	$ 95.7	$ 95.3
Distributions paid to preferred unitholders	$ 0.2	$ 0.2	$ 0.7	$ 0.7

Capital - Incentive and Share-b

Capital - Incentive and Share-based Compensation (Details) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	May 31, 2019USD ($)shares	Mar. 31, 2019USD ($)vesting_installmentshares	Sep. 30, 2019USD ($)shares	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)	May 16, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate look-back period (in years)					6 years
Weighted-average per unit or share fair value (in USD per share) | $ / shares					$ 9.55
Age of grantee at which LTIP unit and restricted stock awards immediately vest					60 years
Period of service, upon completion of which, grantee's LTIP unit and restricted stock awards will immediately vest (in years)					10 years
Awards that meet age and service requirements for vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Noncash share-based compensation expense recognized | $			$ 0.3	$ 0.4	$ 1.8	$ 1.7
Unrecognized compensation expense | $			1.4		$ 1.4
Unrecognized compensation expense, period for recognition					2 years 3 months 18 days
Awards that do not meet age and service requirements for vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Noncash share-based compensation expense recognized | $			3.4	$ 4.5	$ 13.6	$ 12.4
Unrecognized compensation expense | $			$ 33.8		$ 33.8
Unrecognized compensation expense, period for recognition					2 years 3 months 18 days
Long-Term Incentive Plan Units and Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of share-based awards granted in period | $					$ 27.9
Weighted-average per unit or share fair value (in USD per share) | $ / shares					$ 9.55
Dividend rate (as a percent)					2.40%
Risk free interest rate, minimum (as a percent)					2.48%
Risk free interest rate, maximum (as a percent)					2.63%
Expected price volatility, minimum (as a percent)					17.00%
Expected price volatility, maximum (as a percent)					22.00%
Time Based Long-Tern Incentive Plan Unit | 2013 Plan Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		61,432
Fair value of share-based awards granted in period | $		$ 2
Award vesting period		4 years
Number of vesting installments | vesting_installment		3
Performance Based Long-Term Incentive Plan Unit | 2013 Plan Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		113,383
Fair value of share-based awards granted in period | $		$ 0.9
Award vesting period		3 years
Number of vesting installments | vesting_installment		2
Time Restricted Shares | 2013 Plan Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		69,358
Executive Officer | Time Based Long-Tern Incentive Plan Unit | 2013 Plan Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		461,693
Fair value of share-based awards granted in period | $		$ 6.4
Executive Officer | Time Based Long-Tern Incentive Plan Unit | 2013 Plan Units, connected with bonus program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		334,952
Fair value of share-based awards granted in period | $		$ 4.6
Award vesting period					3 years
Vesting percentage of award face amount			125.00%		125.00%
Executive Officer | Time Based Long-Tern Incentive Plan Unit | Vesting immediately
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		26,056
Executive Officer | Time Based Long-Tern Incentive Plan Unit | Vest ratably over three years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		308,896
Award vesting period		3 years
Executive Officer | Time Based Long-Tern Incentive Plan Unit | Vest in two equal annual installments
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting installments | vesting_installment		2
Executive Officer | Performance Based Long-Term Incentive Plan Unit | 2013 Plan Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares		1,806,520
Fair value of share-based awards granted in period | $		$ 12.8
Director | Time Based Long-Tern Incentive Plan Unit | 2019 Plan Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) | shares	70,746
Fair value of share-based awards granted in period | $	$ 1
Award vesting period	3 years
2019 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under the plan (in shares) | shares			11,000,000		11,000,000		11,000,000
Number of shares that remain available for future issuance (in shares) | shares			11,500,000		11,500,000
Minimum | Long-Term Incentive Plan Units and Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term					2 years
Maximum | Long-Term Incentive Plan Units and Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term					5 years 3 months 18 days

Capital - Summary of ESRT Restr

Capital - Summary of ESRT Restricted Stock and LTIP Unit Activity (Details)	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Weighted Average Grant Fair Value
Beginning balance, Unvested (in USD per share) | $ / shares	$ 9.68
Vested (in USD per share) | $ / shares	15.98
Granted (in USD per share) | $ / shares	9.55
Forfeited or unearned (in USD per share) | $ / shares	7.34
Ending balance, Unvested (in USD per share) | $ / shares	$ 9.72
Restricted Stock
Restricted Stock and LTIP Units
Beginning balance, Unvested (in shares)	91,158
Vested (in shares)	(35,724)
Granted (in shares)	69,358
Forfeited or unearned (in shares)	(5,762)
Ending balance, Unvested (in shares)	119,030
LTIP Units
Restricted Stock and LTIP Units
Beginning balance, Unvested (in shares)	5,702,821
Vested (in shares)	(598,402)
Granted (in shares)	2,848,726
Forfeited or unearned (in shares)	(1,972,548)
Ending balance, Unvested (in shares)	5,980,597

Capital - Earnings Per Unit (De

Capital - Earnings Per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income	$ 26,784	$ 29,230	$ 55,570	$ 77,472
Private perpetual preferred unit distributions	(234)	(234)	(702)	(702)
Earnings allocated to unvested units	(243)	(212)	(646)	(586)
Net income attributable to common unitholders - basic and diluted	$ 26,307	$ 28,784	$ 54,222	$ 76,184
Denominator:
Weighted average units outstanding - basic (in units)	298,151,000	297,478,000	298,117,000	297,180,000
Effect of dilutive securities:
Stock-based compensation plans (in units)	0	0	0	1,000
Weighted average units outstanding - diluted (in units)	298,151,000	297,478,000	298,117,000	297,181,000
Earnings per share:
Basic (in USD per unit)	$ 0.09	$ 0.10	$ 0.18	$ 0.26
Diluted (in USD per unit)	$ 0.09	$ 0.10	$ 0.18	$ 0.26
Antidilutive securities (in units)	452,457	541,947	288,053	458,698

Related Party Transactions (Det

Related Party Transactions (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)ft²propertydirector	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)ft²propertydirector	Sep. 30, 2018USD ($)
Related Party Transaction [Line Items]
Area of real estate property (in square feet) | ft²	10,100,000		10,100,000
Number of directors | director	1		1
Affliliated entity | Supervisory fee revenue
Related Party Transaction [Line Items]
Revenue from related parties	$ 0.2	$ 0.2	$ 0.7	$ 0.9
Affliliated entity | Property management fee revenue
Related Party Transaction [Line Items]
Revenue from related parties	0.1	0.1	0.2	0.3
Affliliated entity | Leased space rental
Related Party Transaction [Line Items]
Revenue from related parties	$ 0.1	$ 0.1	$ 0.2	$ 0.3
Number of properties | property	1		1
Lease cancellation, notice period (in days)			90 days
Affliliated entity | Annualized rent revenue
Related Party Transaction [Line Items]
Revenue from related parties			$ 4.6
Undivided Interest
Related Party Transaction [Line Items]
Area of real estate property (in square feet) | ft²	5,351		5,351
Chairman emeritus | Leased space rental
Related Party Transaction [Line Items]
Percentage of lease space occupied by Chairman emeritus and employee			15.00%

Segment Reporting - Narrative

Segment Reporting - Narrative (Details)	9 Months Ended
	Sep. 30, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Reporting - Components

Segment Reporting - Components of Segment Profit for Each Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenues:
Rental revenue	$ 150,225		$ 434,713
Rental revenue		$ 123,621		$ 369,970
Intercompany rental revenue	0	0	0	0
Tenant expense reimbursement	0	18,627	0	52,626
Observatory revenue	37,575	40,241	91,039	96,691
Lease termination fees	2,361	1,185	3,112	2,164
Third-party management and other fees	304	312	955	1,151
Other revenue and fees	2,408	2,416	6,591	9,600
Total revenues	192,873	186,402	536,410	532,202
Operating expenses:
Property operating expenses	47,894	42,772	131,076	126,375
Intercompany rent expense	0	0	0	0
Ground rent expense	2,331	2,331	6,994	6,994
General and administrative expenses	14,421	13,148	44,445	39,001
Observatory expenses	9,089	8,854	25,024	23,868
Real estate taxes	29,599	28,284	86,098	81,771
Depreciation and amortization	44,260	42,475	135,179	121,826
Total operating expenses	147,594	137,864	428,816	399,835
Total operating income	45,279	48,538	107,594	132,367
Other income (expense):
Interest income	2,269	3,485	9,907	7,209
Interest expense	(19,426)	(20,658)	(60,712)	(58,774)
Income before income taxes	28,122	31,365	56,789	80,802
Income tax expense	(1,338)	(2,135)	(1,219)	(3,330)
Net income	26,784	29,230	55,570	77,472
Segment assets	3,925,317	4,166,832	3,925,317	4,166,832	$ 4,195,780
Expenditures for segment assets	61,276	67,120	181,568	190,359
Intersegment Elimination
Revenues:
Rental revenue	0		0
Rental revenue		0		0
Intercompany rental revenue	(23,242)	(23,805)	(58,754)	(59,356)
Tenant expense reimbursement		0		0
Observatory revenue	0	0	0	0
Lease termination fees	0	0	0	0
Third-party management and other fees	0	0	0	0
Other revenue and fees	0	0	0	0
Total revenues	(23,242)	(23,805)	(58,754)	(59,356)
Operating expenses:
Property operating expenses	0	0	0	0
Intercompany rent expense	(23,242)	(23,805)	(58,754)	(59,356)
Ground rent expense	0	0	0	0
General and administrative expenses	0	0	0	0
Observatory expenses	0	0	0	0
Real estate taxes	0	0	0	0
Depreciation and amortization	0	0	0	0
Total operating expenses	(23,242)	(23,805)	(58,754)	(59,356)
Total operating income	0	0	0	0
Other income (expense):
Interest income	0	0	0	0
Interest expense	0	0	0	0
Income before income taxes	0	0	0	0
Income tax expense	0	0	0	0
Net income	0	0	0	0
Segment assets	0	0	0	0
Expenditures for segment assets	0	0	0	0
Real Estate | Operating Segments
Revenues:
Rental revenue	150,225		434,713
Rental revenue		123,621		369,970
Intercompany rental revenue	23,242	23,805	58,754	59,356
Tenant expense reimbursement		18,627		52,626
Observatory revenue	0	0	0	0
Lease termination fees	2,361	1,185	3,112	2,164
Third-party management and other fees	304	312	955	1,151
Other revenue and fees	2,408	2,416	6,591	9,600
Total revenues	178,540	169,966	504,125	494,867
Operating expenses:
Property operating expenses	47,894	42,772	131,076	126,375
Intercompany rent expense	0	0	0	0
Ground rent expense	2,331	2,331	6,994	6,994
General and administrative expenses	14,421	13,148	44,445	39,001
Observatory expenses	0	0	0	0
Real estate taxes	29,599	28,284	86,098	81,771
Depreciation and amortization	44,253	42,458	135,157	121,775
Total operating expenses	138,498	128,993	403,770	375,916
Total operating income	40,042	40,973	100,355	118,951
Other income (expense):
Interest income	2,269	3,485	9,907	7,209
Interest expense	(19,426)	(20,658)	(60,712)	(58,774)
Income before income taxes	22,885	23,800	49,550	67,386
Income tax expense	(267)	(277)	(762)	(852)
Net income	22,618	23,523	48,788	66,534
Segment assets	3,659,592	3,904,454	3,659,592	3,904,454
Expenditures for segment assets	42,901	52,613	134,865	148,429
Observatory | Operating Segments
Revenues:
Rental revenue	0		0
Rental revenue		0		0
Intercompany rental revenue	0	0	0	0
Tenant expense reimbursement		0		0
Observatory revenue	37,575	40,241	91,039	96,691
Lease termination fees	0	0	0	0
Third-party management and other fees	0	0	0	0
Other revenue and fees	0	0	0	0
Total revenues	37,575	40,241	91,039	96,691
Operating expenses:
Property operating expenses	0	0	0	0
Intercompany rent expense	23,242	23,805	58,754	59,356
Ground rent expense	0	0	0	0
General and administrative expenses	0	0	0	0
Observatory expenses	9,089	8,854	25,024	23,868
Real estate taxes	0	0	0	0
Depreciation and amortization	7	17	22	51
Total operating expenses	32,338	32,676	83,800	83,275
Total operating income	5,237	7,565	7,239	13,416
Other income (expense):
Interest income	0	0	0	0
Interest expense	0	0	0	0
Income before income taxes	5,237	7,565	7,239	13,416
Income tax expense	(1,071)	(1,858)	(457)	(2,478)
Net income	4,166	5,707	6,782	10,938
Segment assets	265,725	262,378	265,725	262,378
Expenditures for segment assets	$ 18,375	$ 14,507	$ 46,703	$ 41,930