Fair Value of Financial Instruments - Schedule of Financial Instruments that are Not Reported at Fair Value (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	$ 30,558	$ 84,724	$ 30,558	$ 84,724
Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	84,700		84,700
Significant Unobservable Inputs \| Gross Principal Balance \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	350,000		350,000		$ 350,000
Significant Unobservable Inputs \| Fair Value \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	$ 279,805		$ 279,805		287,460
Mortgage note payable — 1140 Avenue of the Americas \| Measurement Input, Default Rate \| Valuation Technique, Discounted Cash Flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Measurement Input	0.085		0.085
Mortgage note payable — 1140 Avenue of the Americas \| Measurement Input, Capitalization Rate \| Valuation Technique, Discounted Cash Flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Measurement Input	0.070		0.070
Mortgage note payable — 1140 Avenue of the Americas \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	$ 7,100		$ 7,100		66,100
Mortgage note payable — 1140 Avenue of the Americas \| Significant Unobservable Inputs \| Gross Principal Balance \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	99,000		99,000		99,000
Mortgage note payable — 1140 Avenue of the Americas \| Significant Unobservable Inputs \| Fair Value \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	60,521		60,521		69,238
Mortgage note payable — 123 William Street \| Significant Unobservable Inputs \| Gross Principal Balance \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	140,000		140,000		140,000
Mortgage note payable — 123 William Street \| Significant Unobservable Inputs \| Fair Value \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	$ 135,086		$ 135,086		132,474
400 E. 67th Street - Laurel Condominium / 200 Riverside Boulevard - ICON Garage \| Measurement Input, Default Rate \| Valuation Technique, Discounted Cash Flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Measurement Input	0.085		0.085
400 E. 67th Street - Laurel Condominium / 200 Riverside Boulevard - ICON Garage \| Measurement Input, Capitalization Rate \| Valuation Technique, Discounted Cash Flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Measurement Input	0.070		0.070
400 E. 67th Street - Laurel Condominium / 200 Riverside Boulevard - ICON Garage \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	$ 13,100		$ 13,100		25,800
400 E. 67th Street - Laurel Condominium / 200 Riverside Boulevard - ICON Garage \| Significant Unobservable Inputs \| Gross Principal Balance \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	50,000		50,000		50,000
400 E. 67th Street - Laurel Condominium / 200 Riverside Boulevard - ICON Garage \| Significant Unobservable Inputs \| Fair Value \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	28,239		28,239		31,671
Mortgage note payable — 8713 Fifth Avenue \| Significant Unobservable Inputs \| Gross Principal Balance \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	10,000		10,000		10,000
Mortgage note payable — 8713 Fifth Avenue \| Significant Unobservable Inputs \| Fair Value \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	$ 9,446		$ 9,446		9,181
Mortgage note payable — 196 Orchard Street \| Measurement Input, Default Rate \| Valuation Technique, Discounted Cash Flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Measurement Input	0.085		0.085
Mortgage note payable — 196 Orchard Street \| Measurement Input, Capitalization Rate \| Valuation Technique, Discounted Cash Flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Measurement Input	0.070		0.070
Mortgage note payable — 196 Orchard Street \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	$ 10,300		$ 10,300
Mortgage note payable — 196 Orchard Street \| Significant Unobservable Inputs \| Gross Principal Balance \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	51,000		51,000		51,000
Mortgage note payable — 196 Orchard Street \| Significant Unobservable Inputs \| Fair Value \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable	46,513		$ 46,513		$ 44,896
400 E. 67th Street Laurel Condominium \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	3,100
200 Riverside Boulevard \| Mortgages Note Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairments of real estate investments	$ 9,900