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Noncontrolling Interests (Property Partnerships) (Narrative) (Details) $ in Thousands |  | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | ---
Jul. 28, 2023 USD ($) | Sep. 30, 2023 USD ($) | Sep. 30, 2023 USD ($) | Dec. 31, 2022 USD ($)
Noncontrolling Interest [Line Items] |  |  |  |
Noncontrolling Interest in Limited Partnerships |  | $ 1,588,906 | $ 1,588,906 | $ 1,547,317
Contribution of Property |  | $ 17,519 | $ 17,519 |
Variable Interest Entity, Primary Beneficiary [Member] | 343 Madison Avenue |  |  |  |
Noncontrolling Interest [Line Items] |  |  |  |
Consolidated Entities, Ownership Percentage | 0.55 |  |  |
Payments to Acquire Investments | $ 5,900 |  |  |
Contribution of Property | $ 21,400 |  |  |
Variable Interest Entity, Not Primary Beneficiary | 343 Madison Avenue |  |  |  |
Noncontrolling Interest [Line Items] |  |  |  |
Consolidated Entities, Ownership Percentage | 0.45 |  |  |
Payments to Acquire Investments | $ 4,800 |  |  |
Contribution of Property | $ 17,500 |  |  |

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