Schedule III - Real Estate and Accumulated Depreciation (Details) $ in Thousands	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) ft²
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	$ 2,075,222
Initial Cost
Land	1,847,154
Building & Improvements	4,742,774
Cost Capitalized Subsequent To Acquisition
Land	(147,939)
Building & Improvements	717,643
Gross Amount at Which Carried at Close of Period
Land	1,699,215
Building & Improvements	5,460,417
Total	7,159,632	$ 6,607,741	$ 6,102,864	$ 9,198,799
Accumulated Depreciation	2,306,377	$ 2,126,081	$ 1,968,004	$ 2,039,554
420 Lexington Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	258,523
Initial Cost
Land	0
Building & Improvements	333,499
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	106,916
Gross Amount at Which Carried at Close of Period
Land	0
Building & Improvements	440,415
Total	440,415
Accumulated Depreciation	255,135
711 Third Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	19,844
Building & Improvements	115,769
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	23,046
Gross Amount at Which Carried at Close of Period
Land	19,844
Building & Improvements	138,815
Total	158,659
Accumulated Depreciation	91,323
555 W. 57th Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	18,846
Building & Improvements	140,946
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	25,859
Gross Amount at Which Carried at Close of Period
Land	18,846
Building & Improvements	166,805
Total	185,651
Accumulated Depreciation	109,532
461 Fifth Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	0
Building & Improvements	88,276
Cost Capitalized Subsequent To Acquisition
Land	28,873
Building & Improvements	19,632
Gross Amount at Which Carried at Close of Period
Land	28,873
Building & Improvements	107,908
Total	136,781
Accumulated Depreciation	54,641
750 Third Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	51,093
Building & Improvements	251,523
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	168,369
Gross Amount at Which Carried at Close of Period
Land	51,093
Building & Improvements	419,892
Total	470,985
Accumulated Depreciation	121,610
485 Lexington Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	450,000
Initial Cost
Land	78,282
Building & Improvements	452,631
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	1,027
Gross Amount at Which Carried at Close of Period
Land	78,282
Building & Improvements	453,658
Total	531,940
Accumulated Depreciation	236,495
810 Seventh Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	114,077
Building & Improvements	550,819
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	37,307
Gross Amount at Which Carried at Close of Period
Land	114,077
Building & Improvements	588,126
Total	702,203
Accumulated Depreciation	268,101
1185 Avenue of the Americas
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	0
Building & Improvements	791,106
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	68,298
Gross Amount at Which Carried at Close of Period
Land	0
Building & Improvements	859,404
Total	859,404
Accumulated Depreciation	445,591
1350 Avenue of the Americas
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	90,941
Building & Improvements	431,517
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	29,461
Gross Amount at Which Carried at Close of Period
Land	90,941
Building & Improvements	460,978
Total	551,919
Accumulated Depreciation	226,360
1-6 Landmark Square
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	100,000
Initial Cost
Land	27,852
Building & Improvements	161,343
Cost Capitalized Subsequent To Acquisition
Land	(6,939)
Building & Improvements	(5,495)
Gross Amount at Which Carried at Close of Period
Land	20,913
Building & Improvements	155,848
Total	176,761
Accumulated Depreciation	57,175
7 Landmark Square
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	1,721
Building & Improvements	8,417
Cost Capitalized Subsequent To Acquisition
Land	(1,338)
Building & Improvements	(6,207)
Gross Amount at Which Carried at Close of Period
Land	383
Building & Improvements	2,210
Total	2,593
Accumulated Depreciation	875
100 Church Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	365,000
Initial Cost
Land	34,994
Building & Improvements	183,932
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	18,086
Gross Amount at Which Carried at Close of Period
Land	34,994
Building & Improvements	202,018
Total	237,012
Accumulated Depreciation	89,348
125 Park Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	120,900
Building & Improvements	270,598
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	36,111
Gross Amount at Which Carried at Close of Period
Land	120,900
Building & Improvements	306,709
Total	427,609
Accumulated Depreciation	149,136
19 East 65th Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	8,603
Building & Improvements	2,074
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	10,967
Gross Amount at Which Carried at Close of Period
Land	8,603
Building & Improvements	13,041
Total	21,644
Accumulated Depreciation	10
304 Park Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	54,489
Building & Improvements	90,643
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	14,031
Gross Amount at Which Carried at Close of Period
Land	54,489
Building & Improvements	104,674
Total	159,163
Accumulated Depreciation	40,861
760 Madison Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	284,286
Building & Improvements	8,314
Cost Capitalized Subsequent To Acquisition
Land	(3,205)
Building & Improvements	93,372
Gross Amount at Which Carried at Close of Period
Land	281,081
Building & Improvements	101,686
Total	382,767
Accumulated Depreciation	7,703
110 Greene Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	45,120
Building & Improvements	228,393
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	5,817
Gross Amount at Which Carried at Close of Period
Land	45,120
Building & Improvements	234,210
Total	279,330
Accumulated Depreciation	70,977
7 Dey / 185 Broadway
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	190,149
Initial Cost
Land	45,540
Building & Improvements	27,865
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	211,211
Gross Amount at Which Carried at Close of Period
Land	45,540
Building & Improvements	239,076
Total	284,616
Accumulated Depreciation	31,567
885 Third Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	138,444
Building & Improvements	244,040
Cost Capitalized Subsequent To Acquisition
Land	(138,444)
Building & Improvements	(114,346)
Gross Amount at Which Carried at Close of Period
Land	0
Building & Improvements	129,694
Total	129,694
Accumulated Depreciation	20,508
Approximate Square Feet | ft²				218,796
690 Madison Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	13,820
Building & Improvements	51,732
Cost Capitalized Subsequent To Acquisition
Land	(7,985)
Building & Improvements	(27,336)
Gross Amount at Which Carried at Close of Period
Land	5,835
Building & Improvements	24,396
Total	30,231
Accumulated Depreciation	5,653
10 East 53rd Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	204,550
Initial Cost
Land	104,143
Building & Improvements	62,470
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	1,727
Gross Amount at Which Carried at Close of Period
Land	104,143
Building & Improvements	64,197
Total	168,340
Accumulated Depreciation	10,897
500 Park Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	80,000
Initial Cost
Land	91,920
Building & Improvements	15,762
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	0
Gross Amount at Which Carried at Close of Period
Land	91,920
Building & Improvements	15,762
Total	107,682
Accumulated Depreciation	1,776
315 West 33rd Street
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	250,000
Initial Cost
Land	179,391
Building & Improvements	179,776
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	0
Gross Amount at Which Carried at Close of Period
Land	179,391
Building & Improvements	179,776
Total	359,167
Accumulated Depreciation	1,650
346 Madison Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	162,262
Building & Improvements	1,797
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	0
Gross Amount at Which Carried at Close of Period
Land	162,262
Building & Improvements	1,797
Total	164,059
Accumulated Depreciation	0
800 Third Avenue
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	177,000
Initial Cost
Land	139,949
Building & Improvements	33,308
Cost Capitalized Subsequent To Acquisition
Land	0
Building & Improvements	0
Gross Amount at Which Carried at Close of Period
Land	139,949
Building & Improvements	33,308
Total	173,257
Accumulated Depreciation	1,122
Other
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Initial Cost
Land	20,637
Building & Improvements	16,224
Cost Capitalized Subsequent To Acquisition
Land	(18,901)
Building & Improvements	(210)
Gross Amount at Which Carried at Close of Period
Land	1,736
Building & Improvements	16,014
Total	17,750
Accumulated Depreciation	$ 8,331
885 Third Avenue
Gross Amount at Which Carried at Close of Period
Approximate Square Feet | ft²				414,317