Organization and Basis of Presentation - Schedule of Commercial Office Properties (Details)	Jun. 30, 2022 ft² building
Real estate properties
Number of Buildings | building	50
Approximate Square Feet unaudited (sqft)	27,211,821
Weighted Average Occupancy unaudited (as a percent)	90.60%
Commercial properties
Real estate properties
Number of Buildings | building	49
Approximate Square Feet unaudited (sqft)	27,071,439
Weighted Average Occupancy unaudited (as a percent)	90.70%
Consolidated properties
Real estate properties
Number of Buildings | building	27
Approximate Square Feet unaudited (sqft)	11,293,134
Consolidated properties | Commercial properties
Real estate properties
Number of Buildings | building	26
Approximate Square Feet unaudited (sqft)	11,152,752
Unconsolidated properties
Real estate properties
Number of Buildings | building	23
Approximate Square Feet unaudited (sqft)	15,918,687
Unconsolidated properties | Commercial properties
Real estate properties
Number of Buildings | building	23
Approximate Square Feet unaudited (sqft)	15,918,687
Manhattan
Real estate properties
Number of Buildings | building	42
Approximate Square Feet unaudited (sqft)	26,208,639
Weighted Average Occupancy unaudited (as a percent)	91.20%
Manhattan | Office
Real estate properties
Number of Buildings | building	24
Approximate Square Feet unaudited (sqft)	22,178,726
Weighted Average Occupancy unaudited (as a percent)	91.20%
Manhattan | Retail
Real estate properties
Number of Buildings | building	11
Approximate Square Feet unaudited (sqft)	319,884
Weighted Average Occupancy unaudited (as a percent)	91.20%
Manhattan | Development/Redevelopment
Real estate properties
Number of Buildings | building	7
Approximate Square Feet unaudited (sqft)	3,710,029
Manhattan | Residential
Real estate properties
Number of Buildings | building	1
Approximate Square Feet unaudited (sqft)	140,382
Weighted Average Occupancy unaudited (as a percent)	76.10%
Manhattan | Consolidated properties
Real estate properties
Number of Buildings | building	19
Approximate Square Feet unaudited (sqft)	10,289,952
Manhattan | Consolidated properties | Office
Real estate properties
Number of Buildings | building	12
Approximate Square Feet unaudited (sqft)	8,180,345
Manhattan | Consolidated properties | Retail
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	17,888
Manhattan | Consolidated properties | Retail | 7 Dey / 185 Broadway
Real estate properties
Approximate Square Feet unaudited (sqft)	140,382
Manhattan | Consolidated properties | Development/Redevelopment
Real estate properties
Number of Buildings | building	5
Approximate Square Feet unaudited (sqft)	2,091,719
Manhattan | Consolidated properties | Residential
Real estate properties
Number of Buildings | building	1
Approximate Square Feet unaudited (sqft)	140,382
Manhattan | Consolidated properties | Residential | 7 Dey / 185 Broadway
Real estate properties
Approximate Square Feet unaudited (sqft)	50,206
Manhattan | Unconsolidated properties
Real estate properties
Number of Buildings | building	23
Approximate Square Feet unaudited (sqft)	15,918,687
Manhattan | Unconsolidated properties | Office
Real estate properties
Number of Buildings | building	12
Approximate Square Feet unaudited (sqft)	13,998,381
Manhattan | Unconsolidated properties | Retail
Real estate properties
Number of Buildings | building	9
Approximate Square Feet unaudited (sqft)	301,996
Manhattan | Unconsolidated properties | Development/Redevelopment
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	1,618,310
Manhattan | Unconsolidated properties | Residential
Real estate properties
Number of Buildings | building	0
Approximate Square Feet unaudited (sqft)	0
Suburban | Office
Real estate properties
Number of Buildings | building	7
Approximate Square Feet unaudited (sqft)	862,800
Weighted Average Occupancy unaudited (as a percent)	78.30%
Suburban | Consolidated properties | Office
Real estate properties
Number of Buildings | building	7
Approximate Square Feet unaudited (sqft)	862,800
Suburban | Unconsolidated properties | Office
Real estate properties
Number of Buildings | building	0
Approximate Square Feet unaudited (sqft)	0