Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

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

Summary of identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases)

The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of December 31, 2022 and 2021 (in thousands):

	December 31,
	2022		2021
Identified intangible assets (included in other assets):
Gross amount	$	403,552	$	199,722
Accumulated amortization	(190,066)		(182,643)
Net (1)	$	213,486	$	17,079
Identified intangible liabilities (included in deferred revenue):
Gross amount	$	361,338	$	212,767
Accumulated amortization	(212,191)		(210,262)
Net (1)	$	149,147	$	2,505

(1)    As of December 31, 2022, no net intangible assets and no net intangible liabilities were reclassified to assets held for sale and liabilities related to assets held for sale. As of December 31, 2021, $1.8 million of net intangible assets and no net intangible liabilities were reclassified to assets held for sale and liabilities related to assets held for sale.

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):    

2023	$	(23,580)
2024	(14,878)
2025	(14,760)
2026	(11,775)
2027	(11,029)

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):

2023	$	65,130
2024	38,982
2025	37,298
2026	31,381
2027	25,058

Schedule of marketable securities

As of December 31, 2022 and 2021, we held the following marketable securities (in thousands):

	December 31,
	2022		2021
Commercial mortgage-backed securities	$	11,240	$	24,146
Total marketable securities available-for-sale	$	11,240	$	24,146
Equity marketable securities	$	—	$	10,606
Total investment in marketable securities	$	11,240	$	34,752

Schedules of concentration of risk, by risk factor

For the years ended December 31, 2022, 2021, and 2020, 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	2022	Property	2021	Property	2020
One Vanderbilt Avenue	14.1%	11 Madison Avenue	10.8%	11 Madison Avenue	8.2%
245 Park Avenue	10.0%	420 Lexington Avenue	8.3%	420 Lexington Avenue	7.5%
11 Madison Avenue	7.8%	1515 Broadway	8.1%	1185 Avenue of the Americas	6.9%
420 Lexington Avenue	6.3%	1185 Avenue of the Americas	8.0%	1515 Broadway	6.6%
1515 Broadway	5.8%	280 Park Avenue	6.7%	220 East 42nd Street	5.9%
1185 Avenue of the Americas	5.1%	919 Third Avenue	5.3%	280 Park Ave	5.4%
280 Park Avenue	5.1%	485 Lexington Avenue	5.3%
		555 West 57th Street	5.2%