Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Schedule of Estimated Useful Lives

Properties other than Right of use assets - operating leases are depreciated using the straight-line method over the estimated useful lives of the assets. The estimated useful lives are as follows:

Category	Term
Building (fee ownership)	40 years
Building improvements	shorter of remaining life of the building or useful life
Building (leasehold interest)	lesser of 40 years or remaining term of the lease
Right of use assets - financing leases	lesser of 40 years or remaining lease term
Furniture and fixtures	4 to 7 years
Tenant improvements	shorter of remaining term of the lease or useful life

Schedule of Identified Intangible Assets and Intangible Liabilities

The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of December 31, 2023 and 2022 (in thousands):

	December 31, 2023		December 31, 2022
Identified intangible assets (included in other assets):
Gross amount	$	189,680	$	403,552
Accumulated amortization	(184,902)		(190,066)
Net	$	4,778	$	213,486
Identified intangible liabilities (included in deferred revenue):
Gross amount	$	205,394	$	361,338
Accumulated amortization	(202,089)		(212,191)
Net	$	3,305	$	149,147

Schedule of Estimated Annual Amortization of Acquired Above-market Leases, Net of Acquired Below-market Leases

The estimated annual amortization of acquired above-market leases, net of acquired (below-market) leases (a component of rental revenue), for each of the five succeeding years is as follows (in thousands):    

2024	$	36
2025	234
2026	205
2027	184
2028	70

Schedule of Estimated Annual Amortization of all Other Identifiable Assets

The estimated annual amortization of all other identifiable assets (a component of depreciation and amortization expense) including tenant improvements for each of the five succeeding years is as follows (in thousands):

2024	$	1,096
2025	728
2026	551
2027	312
2028	158

Schedule of Marketable Securities

As of December 31, 2023 and 2022, we held the following marketable securities (in thousands):

	December 31, 2023		December 31, 2022
Commercial mortgage-backed securities	$	9,591	$	11,240
Total investment in marketable securities	$	9,591	$	11,240

Schedule of Properties Contributed of Annualized Cash Rent

For the years ended December 31, 2023, 2022, and 2021, the following properties contributed more than 5.0% of our annualized cash rent from office properties, including our share of annualized cash rent from joint venture office properties:

Property	2023	Property	2022	Property	2021
One Vanderbilt Avenue	16.0%	One Vanderbilt Avenue	14.1%	11 Madison Avenue	10.8%
11 Madison Avenue	8.3%	245 Park Avenue	10.0%	420 Lexington Avenue	8.3%
420 Lexington Avenue	6.7%	11 Madison Avenue	7.8%	1515 Broadway	8.1%
1515 Broadway	6.4%	420 Lexington Avenue	6.3%	1185 Avenue of the Americas	8.0%
1185 Avenue of the Americas	5.6%	1515 Broadway	5.8%	280 Park Avenue	6.7%
280 Park Avenue	5.5%	1185 Avenue of the Americas	5.1%	919 Third Avenue	5.3%
245 Park Avenue	5.5%	280 Park Avenue	5.1%	485 Lexington Avenue	5.3%
				555 West 57th Street	5.2%