Real Estate and Accumulated Depreciation - Schedule III (Summary of Real Estate Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	$ 350,000
Land	134,782
Building and Improvements	426,325
Costs Capitalized Subsequent to Acquisition	(90,275)
Gross amount carried	470,831	$ 668,200	$ 769,286	$ 765,176
Accumulated depreciation	77,947	118,252	$ 131,467	$ 112,641
Gross Carrying Amount	19,063	$ 56,929
Tax basis	555,500
Accumulated amortization	$ 13,200
Building
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Useful life	40 years
Land Improvements
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Useful life	15 years
Minimum | Furniture and Fixtures
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Useful life	5 years
Maximum | Furniture and Fixtures
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Useful life	7 years
400 E. 67th Street - Laurel Condominiums (7)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	$ 44,610
Land	10,653
Building and Improvements	55,682
Costs Capitalized Subsequent to Acquisition	(39,878)
Gross amount carried	26,457
Accumulated depreciation	177
200 Riverside Blvd - ICON Garage
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	5,390
Land	13,787
Building and Improvements	5,510
Costs Capitalized Subsequent to Acquisition	0
Gross amount carried	19,297
Accumulated depreciation	1,412
123 William Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	140,000
Land	50,064
Building and Improvements	182,917
Costs Capitalized Subsequent to Acquisition	36,455
Gross amount carried	269,436
Accumulated depreciation	69,296
1140 Avenue of the Americas
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	99,000
Land	0
Building and Improvements	148,647
Costs Capitalized Subsequent to Acquisition	(88,266)
Gross amount carried	60,381
Accumulated depreciation	2,194
8713 Fifth Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	10,000
Land	4,730
Building and Improvements	9,245
Costs Capitalized Subsequent to Acquisition	1,414
Gross amount carried	15,389
Accumulated depreciation	1,574
196 Orchard Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	51,000
Land	55,548
Building and Improvements	24,324
Costs Capitalized Subsequent to Acquisition	0
Gross amount carried	79,871
Accumulated depreciation	$ 3,294