Summary Of Significant Accounting Policies (Narrative) (Details)		12 Months Ended
		Dec. 31, 2023 USD ($)		Dec. 31, 2022 USD ($)		Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Interest capitalized		$ 42,633,000		$ 52,130,000		$ 53,097,000
Salaries And Related Costs Capitalized		16,100,000		16,100,000		13,700,000
Cash FDIC Insured Limit		250,000
Separate Unrestricted Cash For Deferred Compensation Plan.		36,100,000		32,300,000
Gains (losses) from investments in securities		$ 5,556,000		(6,453,000)		5,626,000
Accounts Receivable, Collection Period Expected		1
Straight Line Rent Adjustments		$ 99,100,000		108,000,000		104,300,000
Above and below market rent adjustments, net		$ 19,200,000		9,100,000		4,200,000
REIT Distribution Requirement		90.00%
Company's Taxable Income Distribution		100.00%
Unrealized Gain (Loss) on Investments		$ 239,000		(150,000)		0
Losses from interest rate contracts		79,000
Prepaid Expense and Other Assets		64,230,000		43,589,000
Carrying Amount [Member]
Summary Of Significant Accounting Policies [Line Items]
3-Month United States Treasury Bills	[1]	302,746,000		0
Unconsolidated Joint Ventures [Member]
Summary Of Significant Accounting Policies [Line Items]
Straight Line Rent Adjustments		28,700,000		62,900,000		17,200,000
Above and below market rent adjustments, net		800,000		400,000		400,000
Impairment loss on investment		$ (272,603,000)	[2]	(50,705,000)	[2]	$ 0
Unconsolidated Joint Ventures [Member] | Dock 72 [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment loss on investment				50,700,000
Interest Rate Cap
Summary Of Significant Accounting Policies [Line Items]
Derivative, Number of Instruments Held		2
Derivative, Notional Amount		$ 600,000,000
Losses from interest rate contracts		79,000
Environmental Focused Investment Fund
Summary Of Significant Accounting Policies [Line Items]
Unrealized Gain (Loss) on Investments		200,000		(200,000)
Prepaid Expense and Other Assets		$ 4,600,000		2,400,000
US Treasury Bill Securities
Summary Of Significant Accounting Policies [Line Items]
U.S. Treasury Bill, Term of Contract		3 months
Cash Equivalents, at Carrying Value				$ 0
3-Month United States Treasury Bills		$ 302,700,000
Unconsolidated Properties | Platform Sixteen, Three Six Zero Park Avenue South, Two Zero Zero Fifth Avenue and Safeco Plaza
Summary Of Significant Accounting Policies [Line Items]
Number of real estate properties		4
Unconsolidated Properties | Unconsolidated Joint Ventures [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment loss on investment		$ 272,600,000

[1] Per the guidance in ASC 326, the Company concluded that the risk of nonpayment is nonexistent because the U.S. Government has a long history with no credit losses and therefore, no credit loss allowance was recorded.

[2] During the year ended December 31, 2023, the Company recognized an other-than-temporary impairment loss on its investments in Platform 16, 360 Park Avenue South, 200 Fifth Avenue and Safeco Plaza of approximately $155.2 million, $54.0 million, $33.4 million and $29.9 million, respectively, as described below in this Note 6. During the year ended December 31, 2022, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture that owns Dock 72 in Brooklyn, New York totaling approximately $50.7 million.