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Investments in Unconsolidated Joint Ventures (Balance Sheets of the Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
ASSETS |  |  |  |  |  |
Total real estate |  | $ 20,593,459 |  | $ 19,496,442 |  |
Total assets |  | 26,026,149 |  | 24,207,669 |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Mortgage and notes payable, net |  | 4,166,379 |  | 3,272,368 |  |
Other Liabilities |  | 445,947 |  | 450,918 |  |
Members’/Partners’ equity |  | 5,876,697 |  | 6,132,919 |  |
Total liabilities and equity / capital |  | 26,026,149 |  | 24,207,669 |  |
Carying value of the Company's investment in unconsolidated joint ventures |  | 1,377,319 |  | 1,715,911 |  |
Right-of-use assets - finance leases |  | 401,680 | [1] | 237,510 |  |
Operating Lease, Right-of-Use Asset | [1] | 324,298 |  | 167,351 |  |
Lease liabilities - finance leases |  | 417,961 |  | 249,335 |  |
Lease Liabilities - Operating Leases |  | 350,391 |  | 204,686 |  |
Sales-type lease receivable, net |  | 13,953 |  | 13,028 |  |
Unconsolidated Joint Ventures [Member] |  |  |  |  |  |
ASSETS |  |  |  |  |  |
Total real estate | [2] | 5,811,763 |  | 6,537,554 |  |
Other assets |  | 682,291 | [3] | 756,786 |  |
Total assets |  | 6,494,054 |  | 7,294,340 |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Mortgage and notes payable, net |  | 3,351,873 |  | 4,022,746 |  |
Other Liabilities | [4] | 361,357 |  | 716,271 |  |
Members’/Partners’ equity |  | 2,780,824 |  | 2,555,323 |  |
Total liabilities and equity / capital |  | 6,494,054 |  | 7,294,340 |  |
Company's share of equity |  | 1,278,483 |  | 1,238,929 |  |
Basis differentials | [5] | 58,933 |  | 391,556 |  |
Carying value of the Company's investment in unconsolidated joint ventures | [6] | 1,337,416 |  | 1,630,485 |  |
Right-of-use assets - finance leases |  |  |  | 248,900 |  |
Operating Lease, Right-of-Use Asset |  | 20,100 |  | 21,200 |  |
Lease liabilities - finance leases |  |  |  | 382,200 |  |
Lease Liabilities - Operating Leases |  | 30,500 |  | 30,500 |  |
Impairment loss on investment |  | (272,603) | [7] | (50,705) | [7] | $ 0
Gain on Unconsolidated Joint Venture Investment |  | 35,756 | [8] | 0 |  | $ 0
Sales-type lease receivable, net |  | 13,900 |  |  |  |
Unconsolidated Joint Ventures [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Other Liabilities |  | 39,900 |  | 85,400 |  |
Colorado Center |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Basis differentials |  | 298,906 |  | 301,820 |  |
Carying value of the Company's investment in unconsolidated joint ventures | [9] | 237,815 |  | 233,862 |  |
200 Fifth Avenue JV LLC |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Basis differentials |  | 58,308 |  | 94,497 |  |
Carying value of the Company's investment in unconsolidated joint ventures | [9] | 75,718 |  | 120,083 |  |
Impairment loss on investment |  | 33,400 |  |  |  |
200 Fifth Avenue JV LLC | Unconsolidated Joint Ventures [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Impairment loss on investment |  | 33,400 |  |  |  |
Gateway Commons Complex [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Basis differentials |  | 48,971 |  | 47,808 |  |
Carying value of the Company's investment in unconsolidated joint ventures | [9] | 376,834 |  | 324,038 |  |
BP/CRF Metropolitan Square LLC [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Other Liabilities | [9] |  |  | 37,629 |  |
Gain on Unconsolidated Joint Venture Investment |  | 35,800 |  |  |  |
Safeco Plaza REIT LLC |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Basis differentials |  | (29,678) |  | (15) |  |
Carying value of the Company's investment in unconsolidated joint ventures | [9] | 44,734 |  | 69,785 |  |
Impairment loss on investment |  | 29,900 |  |  |  |
Safeco Plaza REIT LLC | Unconsolidated Joint Ventures [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Impairment loss on investment |  | 29,900 |  |  |  |
360 PAS Holdco LLC |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Basis differentials |  | (116,534) |  | 3,798 |  |
Carying value of the Company's investment in unconsolidated joint ventures |  | 42,988 |  | 114,992 | [9] |
Impairment loss on investment |  | 54,000 |  |  |  |
360 PAS Holdco LLC | Unconsolidated Joint Ventures [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Impairment loss on investment |  | 54,000 |  |  |  |
Dock 72 |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Other Liabilities | [9] | 11,890 |  | 19,921 |  |
Basis differentials |  | (95,521) |  | (98,980) |  |
Platform 16 |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Basis differentials |  | (143,052) |  | 7,108 |  |
Carying value of the Company's investment in unconsolidated joint ventures | [9] | 45,564 |  | $ 158,109 |  |
Impairment loss on investment |  | 155,200 |  |  |  |
Platform 16 | Unconsolidated Joint Ventures [Member] |  |  |  |  |  |
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY |  |  |  |  |  |
Impairment loss on investment |  | $ 155,200 |  |  |  |
[1] | See Note 4.
[2] | At December 31, 2022, this amount included right of use assets - finance leases totaling approximately $248.9 million. At December 31, 2023 and December 31, 2022, this amount included right of use assets - operating leases totaling approximately $20.1 million and $21.2 million, respectively.
[3] | At December 31, 2023, this amount included sales-type lease receivable, net totaling approximately $13.9 million.
[4] | At December 31, 2022, this amount included lease liabilities - finance leases totaling approximately $382.2 million. At December 31, 2023 and December 31, 2022, this amount included lease liabilities - operating leases totaling approximately $30.5 million.
[5] | 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 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 well as a $35.8 million gain on investment related to Metropolitan Square, as described below in this Note 6. 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:
| December 31, 2023 |  | December 31, 2022
Property | (in thousands)
Colorado Center | $ | 298,906 |  |  | $ | 301,820 |
200 Fifth Avenue | 58,308 |  |  | 94,497 |
Gateway Commons | 48,971 |  |  | 47,808 |
Safeco Plaza | (29,678) |  |  | (15) |
360 Park Avenue South | (116,534) |  |  | 3,798 |
Dock 72 | (95,521) |  |  | (98,980) |
Platform 16 | (143,052) |  |  | 7,108 |
These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.
[6] | Investments with deficit balances aggregating approximately $39.9 million and $85.4 million at December 31, 2023 and December 31, 2022, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.
[7] | 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.
[8] | During the year ended December 31, 2023, the Company completed a restructuring of its ownership in Metropolitan Square, as described below in this Note 6.
[9] | Investments with deficit balances aggregating approximately $39.9 million and $85.4 million at December 31, 2023 and December 31, 2022, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.

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