Dispositions (Narrative) (Details) ft² in Thousands, $ in Thousands				3 Months Ended	9 Months Ended
	Aug. 17, 2022 USD ($) ft²	Jun. 17, 2022 USD ($) ft²	Jan. 13, 2022 USD ($) property	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds from sale of real estate					$ 16,124	$ 97,683
Repayments of long-term debt					1,245,973	$ 1,578,843
SoHo Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties sold | property			2
Proceeds from sale of real estate held-for-investment			$ 84,500
Net proceeds from sale of real estate			81,399
Net gain on sale of real estate			$ 551
Center Building
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate held-for-investment		$ 172,750
Net proceeds from sale of real estate		58,946
Net gain on sale of real estate		$ 15,213
Square footage of real estate property (in sqft) | ft²		498
Center Building | 33‑00 Northern Boulevard Mortgage Loan
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of long-term debt		$ 100,000
40 Fulton Street Office And Retail Building
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate held-for-investment	$ 102,000
Square footage of real estate property (in sqft) | ft²	251
Disposal group, including discontinued operation, assets					$ 64,177
40 Fulton Street Office And Retail Building | Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on sale of real estate				$ 33,000