Schedule III - Real Estate and Accumulated Depreciation - Schedule of Real Estate and Accumulated Depreciation (Details) $ in Thousands	Dec. 31, 2023 USD ($)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	$ 879,195
Initial Cost to the Company
Land and Development Costs	364,266
Building & Improvements	1,095,880
Cost Capitalized Subsequent to Acquisition
Improvements	2,195,046
Gross Amount at which Carried
Land and Development Costs	374,535
Buildings & Improvements	3,280,657
Total	3,655,192
Accumulated Depreciation	(1,250,062)
111 West 33rd Street, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	13,630
Building & Improvements	244,461
Cost Capitalized Subsequent to Acquisition
Improvements	129,859
Gross Amount at which Carried
Land and Development Costs	13,630
Buildings & Improvements	374,320
Total	387,950
Accumulated Depreciation	(118,371)
1400 Broadway, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	0
Building & Improvements	96,338
Cost Capitalized Subsequent to Acquisition
Improvements	102,241
Gross Amount at which Carried
Land and Development Costs	0
Buildings & Improvements	198,579
Total	198,579
Accumulated Depreciation	(72,907)
1333 Broadway, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	159,039
Initial Cost to the Company
Land and Development Costs	91,434
Building & Improvements	120,190
Cost Capitalized Subsequent to Acquisition
Improvements	17,239
Gross Amount at which Carried
Land and Development Costs	91,435
Buildings & Improvements	137,429
Total	228,864
Accumulated Depreciation	(43,811)
1350 Broadway, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	0
Building & Improvements	102,518
Cost Capitalized Subsequent to Acquisition
Improvements	48,815
Gross Amount at which Carried
Land and Development Costs	0
Buildings & Improvements	151,333
Total	151,333
Accumulated Depreciation	(55,169)
250 West 57th Street, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	175,755
Initial Cost to the Company
Land and Development Costs	2,117
Building & Improvements	5,041
Cost Capitalized Subsequent to Acquisition
Improvements	179,876
Gross Amount at which Carried
Land and Development Costs	2,117
Buildings & Improvements	184,917
Total	187,034
Accumulated Depreciation	(74,936)
501 Seventh Avenue, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	1,100
Building & Improvements	2,600
Cost Capitalized Subsequent to Acquisition
Improvements	107,812
Gross Amount at which Carried
Land and Development Costs	1,100
Buildings & Improvements	110,412
Total	111,512
Accumulated Depreciation	(58,775)
1359 Broadway, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	1,233
Building & Improvements	1,809
Cost Capitalized Subsequent to Acquisition
Improvements	83,221
Gross Amount at which Carried
Land and Development Costs	1,233
Buildings & Improvements	85,029
Total	86,262
Accumulated Depreciation	(33,438)
350 Fifth Avenue (Empire State Building), New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	21,551
Building & Improvements	38,934
Cost Capitalized Subsequent to Acquisition
Improvements	1,060,121
Gross Amount at which Carried
Land and Development Costs	21,551
Buildings & Improvements	1,099,055
Total	1,120,606
Accumulated Depreciation	(428,926)
One Grand Central Place, New York, NY | office/ retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	7,240
Building & Improvements	17,490
Cost Capitalized Subsequent to Acquisition
Improvements	310,522
Gross Amount at which Carried
Land and Development Costs	7,222
Buildings & Improvements	328,030
Total	335,252
Accumulated Depreciation	(164,248)
First Stamford Place, Stamford, CT | office
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	177,181
Initial Cost to the Company
Land and Development Costs	22,952
Building & Improvements	122,738
Cost Capitalized Subsequent to Acquisition
Improvements	86,494
Gross Amount at which Carried
Land and Development Costs	24,860
Buildings & Improvements	207,324
Total	232,184
Accumulated Depreciation	(113,916)
One Station Place, Stamford, CT (Metro Center) | office
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	80,117
Initial Cost to the Company
Land and Development Costs	5,313
Building & Improvements	28,602
Cost Capitalized Subsequent to Acquisition
Improvements	40,955
Gross Amount at which Carried
Land and Development Costs	5,313
Buildings & Improvements	69,557
Total	74,870
Accumulated Depreciation	(41,494)
10 Union Square, New York, NY | retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	49,762
Initial Cost to the Company
Land and Development Costs	5,003
Building & Improvements	12,866
Cost Capitalized Subsequent to Acquisition
Improvements	5,742
Gross Amount at which Carried
Land and Development Costs	5,003
Buildings & Improvements	18,608
Total	23,611
Accumulated Depreciation	(10,102)
1542 Third Avenue, New York, NY | retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	29,804
Initial Cost to the Company
Land and Development Costs	2,239
Building & Improvements	15,266
Cost Capitalized Subsequent to Acquisition
Improvements	485
Gross Amount at which Carried
Land and Development Costs	2,239
Buildings & Improvements	15,751
Total	17,990
Accumulated Depreciation	(9,937)
1010 Third Avenue, New York, NY and 77 West 55th Street, New York, NY | retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	34,697
Initial Cost to the Company
Land and Development Costs	4,462
Building & Improvements	15,819
Cost Capitalized Subsequent to Acquisition
Improvements	4,211
Gross Amount at which Carried
Land and Development Costs	4,462
Buildings & Improvements	20,030
Total	24,492
Accumulated Depreciation	(10,937)
345 E 94th Street, New York, NY | multi-family
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	48,646
Initial Cost to the Company
Land and Development Costs	44,228
Building & Improvements	55,766
Cost Capitalized Subsequent to Acquisition
Improvements	4,237
Gross Amount at which Carried
Land and Development Costs	44,228
Buildings & Improvements	60,003
Total	104,231
Accumulated Depreciation	(3,485)
Victory 561 10th Ave, New York, NY | multi-family
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	124,194
Initial Cost to the Company
Land and Development Costs	91,437
Building & Improvements	124,997
Cost Capitalized Subsequent to Acquisition
Improvements	3,461
Gross Amount at which Carried
Land and Development Costs	91,437
Buildings & Improvements	128,458
Total	219,895
Accumulated Depreciation	(7,491)
298 Mulberry, New York, NY | multi-family
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	40,935
Building & Improvements	69,509
Cost Capitalized Subsequent to Acquisition
Improvements	1,475
Gross Amount at which Carried
Land and Development Costs	41,125
Buildings & Improvements	70,794
Total	111,919
Accumulated Depreciation	(1,923)
Williamsburg Retail, Brooklyn, NY | retail
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	4,851
Building & Improvements	20,936
Cost Capitalized Subsequent to Acquisition
Improvements	101
Gross Amount at which Carried
Land and Development Costs	4,860
Buildings & Improvements	21,028
Total	25,888
Accumulated Depreciation	(196)
Property for development at the Transportation Hub in Stamford, CT | land
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost to the Company
Land and Development Costs	4,541
Building & Improvements	0
Cost Capitalized Subsequent to Acquisition
Improvements	8,179
Gross Amount at which Carried
Land and Development Costs	12,720
Buildings & Improvements	0
Total	12,720
Accumulated Depreciation	$ 0