Investments in Unconsolidated Joint Ventures - Schedule of General Information on Joint Ventures (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Jul. 31, 2025 USD ($)	Mar. 31, 2026 USD ($) ft²	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2021
General information on each joint venture
Cash consideration | $		$ 45,924	$ 36,786
Carrying Value | $		118,083		$ 168,358
625 Madison Avenue | Preferred Equity
General information on each joint venture
Carrying value of investment in leasehold interest | $	$ 104,900	235,400
Joint venture sold (as a percent)	0.500
Cash consideration | $	$ 23,700
Proceeds from sale of interest in joint venture | $	$ 10,900
Carrying Value | $		$ 127,100		$ 122,400
Average yield (as a percent)		15.13%
Due from joint ventures | 100 Park Avenue
General information on each joint venture
Economic interest (as a percent)		50.80%
Approximate square feet unaudited (sqft)		834,000
New York State Teacher's Retirement System | Due from joint ventures | 919 Third Avenue
General information on each joint venture
Economic interest (as a percent)		51.00%
Approximate square feet unaudited (sqft)		1,454,000
Private Investor / Wharton Properties | Due from joint ventures | 11 West 34th Street
General information on each joint venture
Economic interest (as a percent)		30.00%
Approximate square feet unaudited (sqft)		17,150
Vornado Realty Trust | Due from joint ventures | 280 Park Avenue
General information on each joint venture
Economic interest (as a percent)		50.00%
Approximate square feet unaudited (sqft)		1,219,158
Wharton Properties | Due from joint ventures | 1552 Broadway
General information on each joint venture
Economic interest (as a percent)		50.00%
Approximate square feet unaudited (sqft)		57,718
Wharton Properties | Due from joint ventures | 650 Fifth Avenue
General information on each joint venture
Economic interest (as a percent)		50.00%
Approximate square feet unaudited (sqft)		69,214
PGIM Real Estate | Due from joint ventures | 11 Madison Avenue
General information on each joint venture
Economic interest (as a percent)		60.00%
Approximate square feet unaudited (sqft)		2,314,000
National Pension Service of Korea / Hines Interest LP / Mori Building Co., Ltd | Due from joint ventures | One Vanderbilt Avenue
General information on each joint venture
Economic interest (as a percent)		55.01%
Approximate square feet unaudited (sqft)		1,657,198
RXR Realty / New York REIT | Due from joint ventures | Worldwide Plaza
General information on each joint venture
Economic interest (as a percent)		25.05%
Approximate square feet unaudited (sqft)		2,048,725
Allianz Real Estate of America | Due from joint ventures | 1515 Broadway
General information on each joint venture
Economic interest (as a percent)		56.87%
Approximate square feet unaudited (sqft)		1,750,000
Israeli Institutional Investor | Due from joint ventures | 2 Herald Square
General information on each joint venture
Economic interest (as a percent)		95.00%
Approximate square feet unaudited (sqft)		369,000
Private Investor | Due from joint ventures | 115 Spring Street
General information on each joint venture
Economic interest (as a percent)		51.00%
Approximate square feet unaudited (sqft)		5,218
Private Investor | Due from joint ventures | 625 Madison Avenue
General information on each joint venture
Economic interest (as a percent)		50.00%
Approximate square feet unaudited (sqft)		563,000
A fund managed by Meritz Alternative Investment Management | Due from joint ventures | 15 Beekman
General information on each joint venture
Economic interest (as a percent)		20.00%
Approximate square feet unaudited (sqft)		221,884
A fund managed by Meritz Alternative Investment Management | Due from joint ventures | 220 East 42nd Street
General information on each joint venture
Economic interest (as a percent)		51.00%
Approximate square feet unaudited (sqft)		1,135,000
National Pension Service of Korea / Hines Interest LP / International Investor | One Madison Avenue
General information on each joint venture
Investment in joint venture aggregate maximum ownership percentage				25.00%	25.00%
National Pension Service of Korea / Hines Interest LP / International Investor | Due from joint ventures | One Madison Avenue
General information on each joint venture
Economic interest (as a percent)		25.50%
Approximate square feet unaudited (sqft)		1,048,700
Korean Institutional Investor / Israeli Institutional Investor | 450 Park Avenue | Third-Party
General information on each joint venture
Investment in joint venture, partners' ownership percentage		25.00%
Equity method investment, ownership percentage		49.90%
Korean Institutional Investor / Israeli Institutional Investor | Due from joint ventures | 450 Park Avenue
General information on each joint venture
Economic interest (as a percent)		25.10%
Approximate square feet unaudited (sqft)		337,000
Investment in joint venture, ownership percentage		25.10%
Equity method investment, ownership percentage		50.10%
U.S. Affiliate of Mori Trust Co., Ltd | Due from joint ventures | 245 Park Avenue
General information on each joint venture
Economic interest (as a percent)		50.10%
Approximate square feet unaudited (sqft)		1,782,793