Investments in Unconsolidated Joint Ventures (Balance Sheets of the Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands			3 Months Ended			9 Months Ended
		Sep. 13, 2023	Sep. 30, 2023		Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022	Dec. 31, 2022
ASSETS
Total real estate			$ 19,868,096			$ 19,868,096			$ 19,496,442
Total assets			24,739,148			24,739,148			24,207,669
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Mortgage and notes payable, net			3,275,974			3,275,974			3,272,368
Other Liabilities			380,014			380,014			450,918
Members’/Partners’ equity			5,788,083			5,788,083			6,132,919
Total liabilities and equity / capital			24,739,148			24,739,148			24,207,669
Carying value of the Company's investment in unconsolidated joint ventures			1,536,822			1,536,822			1,715,911
Right-of-use assets - finance leases			237,532			237,532			237,510
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)	[1]		322,790			322,790			167,351
Lease liabilities - finance leases			253,178			253,178			249,335
Lease Liabilities - Operating Leases			341,299			341,299			204,686
Unconsolidated Joint Ventures [Member]
ASSETS
Total real estate	[2]		6,852,171			6,852,171			6,537,554
Other assets			812,748			812,748			756,786
Total assets			7,664,919			7,664,919			7,294,340
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Mortgage and notes payable, net			4,048,987			4,048,987			4,022,746
Other Liabilities	[3]		782,238			782,238			716,271
Members’/Partners’ equity			2,833,694			2,833,694			2,555,323
Total liabilities and equity / capital			7,664,919			7,664,919			7,294,340
Company's share of equity			1,331,257			1,331,257			1,238,929
Basis differentials	[4]		165,591			165,591			391,556
Carying value of the Company's investment in unconsolidated joint ventures	[5]		1,496,848			1,496,848			1,630,485
Right-of-use assets - finance leases			248,900			248,900			248,900
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)			20,300			20,300			21,200
Lease liabilities - finance leases			378,400			378,400			382,200
Lease Liabilities - Operating Leases			30,500			30,500			30,500
Impairment loss on investment			272,603	[6]	$ 0	272,603	[6]	$ 0
Gain on Unconsolidated Joint Venture Investment			35,756	[7]	$ 0	35,756	[7]	$ 0
Unconsolidated Joint Ventures [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Other Liabilities			40,000			40,000			85,400
Colorado Center
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials			299,637			299,637			301,820
Carying value of the Company's investment in unconsolidated joint ventures	[8]		237,286			237,286			233,862
200 Fifth Avenue JV LLC
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials			60,874			60,874			94,497
Carying value of the Company's investment in unconsolidated joint ventures	[8]		83,244			83,244			120,083
Impairment loss on investment			33,400
Gateway Commons Complex [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials			48,199			48,199			47,808
Carying value of the Company's investment in unconsolidated joint ventures	[8]		362,995			362,995			324,038
BP/CRF Metropolitan Square LLC [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Other Liabilities	[8]		0			0			37,629
Basis differentials			37,053			37,053			1,320
Gain on Unconsolidated Joint Venture Investment		$ 35,800
Safeco Plaza REIT LLC
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials			(29,962)			(29,962)			(15)
Carying value of the Company's investment in unconsolidated joint ventures	[8]		42,330			42,330			69,785
Impairment loss on investment			29,900
360 PAS Holdco LLC
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials			(47,147)			(47,147)			3,798
Carying value of the Company's investment in unconsolidated joint ventures	[8]		59,979			59,979			114,992
Impairment loss on investment			54,000
Dock 72
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Other Liabilities	[8]		12,195			12,195			19,921
Basis differentials			(96,366)			(96,366)			(98,980)
Platform 16
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials			(143,803)			(143,803)			7,108
Carying value of the Company's investment in unconsolidated joint ventures	[8]		35,719			$ 35,719			$ 158,109
Impairment loss on investment			$ 155,200

[1] See Note 4.

[2] At September 30, 2023 and December 31, 2022, this amount included right of use assets - finance leases totaling approximately $248.9 million. At September 30, 2023 and December 31, 2022, this amount included right of use assets - operating leases totaling approximately $20.3 million and $21.2 million, respectively.

[3] At September 30, 2023 and December 31, 2022, this amount included lease liabilities - finance leases totaling approximately $378.4 million and $382.2 million, respectively. At September 30, 2023 and December 31, 2022, this amount included lease liabilities - operating leases totaling approximately $30.5 million.

[4] This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. During the three months ended September 30, 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 well as a $35.8 million gain on investment related to Metropolitan Square, as described below in this Note 5. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows: September 30, 2023December 31, 2022Property(in thousands)Colorado Center$299,637 $301,820 200 Fifth Avenue60,874 94,497 Gateway Commons48,199 47,808 Metropolitan Square37,053 1,320 Safeco Plaza(29,962)(15)360 Park Avenue South(47,147)3,798 Dock 72(96,366)(98,980)Platform 16(143,803)7,108  These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

[5] Investments with deficit balances aggregating approximately $40.0 million and $85.4 million at September 30, 2023 and December 31, 2022, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.

[6] During the three months ended September 30, 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 5.

[7] During the three months ended September 30, 2023, the Company completed a restructuring of its ownership in Metropolitan Square, as described below in this Note 5.

[8] Investments with deficit balances aggregating approximately $40.0 million and $85.4 million at September 30, 2023 and December 31, 2022, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.