Debt - Schedule of Long-Term Debt (Details) - USD ($)		3 Months Ended	6 Months Ended
	Mar. 08, 2024	Mar. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Outstanding borrowings		$ 120,000,000		$ 0
Total principal		2,255,529,000
Deferred financing costs, net		(20,072,000)		(12,365,000)
Revolving credit facility | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	0.10%
Mortgages, senior notes, and unsecured term loan facilities, not including unsecured revolving credit facility
Debt Instrument [Line Items]
Total principal		2,255,529,000		2,256,998,000
Deferred financing costs, net		(9,834,000)		(9,488,000)
Unamortized debt discount		(6,769,000)		(6,964,000)
Total		2,238,926,000		2,240,546,000
Metro Center | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 79,425,000		80,070,000
Stated Rate (as a percent)		3.59%
Effective Rate (as a percent)		3.67%
10 Union Square | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 50,000,000		50,000,000
Stated Rate (as a percent)		3.70%
Effective Rate (as a percent)		3.97%
1542 Third Avenue | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 30,000,000		30,000,000
Stated Rate (as a percent)		4.29%
Effective Rate (as a percent)		4.53%
First Stamford Place | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 175,860,000		175,860,000
Stated Rate (as a percent)		4.28%
Effective Rate (as a percent)		4.73%
First Stamford Place - First Lien | Fixed rate mortgage debt
Debt Instrument [Line Items]
Stated Rate (as a percent)		4.09%
Face amount of debt instrument		$ 164,000,000
First Stamford Place - Second Lien | Fixed rate mortgage debt
Debt Instrument [Line Items]
Stated Rate (as a percent)		6.25%
Face amount of debt instrument		$ 11,900,000
1010 Third Avenue and 77 West 55th Street | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 34,734,000		34,958,000
Stated Rate (as a percent)		4.01%
Effective Rate (as a percent)		4.21%
250 West 57th Street | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 180,000,000		180,000,000
Stated Rate (as a percent)		2.83%
Effective Rate (as a percent)		3.21%
1333 Broadway | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 160,000,000		160,000,000
Stated Rate (as a percent)		4.21%
Effective Rate (as a percent)		4.29%
345 East 94th Street - Series A | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 43,600,000		43,600,000
Effective Rate (as a percent)		3.56%
345 East 94th Street - Series A | Fixed rate mortgage debt | SOFR
Debt Instrument [Line Items]
Variable rate, effective percentage (as a percent)		70.00%
Basis spread on variable rate (as a percent)		0.95%
345 East 94th Street - Series B | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 7,035,000		7,209,000
Effective Rate (as a percent)		3.56%
345 East 94th Street - Series B | Fixed rate mortgage debt | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		2.24%
561 10th Avenue - Series A | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 114,500,000		114,500,000
Effective Rate (as a percent)		3.85%
561 10th Avenue - Series A | Fixed rate mortgage debt | SOFR
Debt Instrument [Line Items]
Variable rate, effective percentage (as a percent)		70.00%
Basis spread on variable rate (as a percent)		1.07%
561 10th Avenue - Series B | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 15,375,000		15,801,000
Effective Rate (as a percent)		3.85%
561 10th Avenue - Series B | Fixed rate mortgage debt | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		2.45%
Total mortgage debt | Fixed rate mortgage debt
Debt Instrument [Line Items]
Fixed rate mortgage debt		$ 890,529,000		891,998,000
Series A | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 100,000,000		100,000,000
Stated Rate (as a percent)		3.93%
Effective Rate (as a percent)		3.96%
Series B | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 125,000,000		125,000,000
Stated Rate (as a percent)		4.09%
Effective Rate (as a percent)		4.12%
Series C | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 125,000,000		125,000,000
Stated Rate (as a percent)		4.18%
Effective Rate (as a percent)		4.21%
Series D | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 115,000,000		115,000,000
Stated Rate (as a percent)		4.08%
Effective Rate (as a percent)		4.11%
Series E | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 160,000,000		160,000,000
Stated Rate (as a percent)		4.26%
Effective Rate (as a percent)		4.27%
Series F | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 175,000,000		175,000,000
Stated Rate (as a percent)		4.44%
Effective Rate (as a percent)		4.45%
Series G | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 100,000,000		100,000,000
Stated Rate (as a percent)		3.61%
Effective Rate (as a percent)		4.89%
Series H | Senior unsecured notes
Debt Instrument [Line Items]
Total		$ 75,000,000		75,000,000
Stated Rate (as a percent)		3.73%
Effective Rate (as a percent)		5.00%
Unsecured term loan facility | Revolving credit facility
Debt Instrument [Line Items]
Outstanding borrowings		$ 175,000,000		175,000,000
Effective Rate (as a percent)		4.51%
Unsecured term loan facility | Revolving credit facility | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		1.50%
Unsecured term loan facility | Revolving credit facility
Debt Instrument [Line Items]
Outstanding borrowings		$ 95,000,000		215,000,000
Effective Rate (as a percent)		4.47%
Unsecured term loan facility | Revolving credit facility | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.50%	1.50%
Unsecured revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Outstanding borrowings		$ 120,000,000		$ 0
Effective Rate (as a percent)		4.03%
Unsecured revolving credit facility | Revolving credit facility | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.30%	1.30%
Maturing In July 2027 | Forecast
Debt Instrument [Line Items]
Debt expected to eliminate			$ 175,900,000