Organization of The Parent Company and The Operating Partnership - Summary of Core Portfolio of Operating Properties and Excludes Development, Redevelopment and Held for Sale (Details)	Mar. 31, 2021 ft² property
Real Estate Properties [Line Items]
Number of properties | property	81
Net rentable area (in square feet) | ft²	13,651,396
Office properties
Real Estate Properties [Line Items]
Number of properties | property	71
Net rentable area (in square feet) | ft²	12,006,744
Mixed-use properties
Real Estate Properties [Line Items]
Number of properties | property	5
Net rentable area (in square feet) | ft²	942,334
Core Properties
Real Estate Properties [Line Items]
Number of properties | property	76
Net rentable area (in square feet) | ft²	12,949,078
Development property
Real Estate Properties [Line Items]
Number of properties | property	1
Net rentable area (in square feet) | ft²	204,000
Redevelopment properties
Real Estate Properties [Line Items]
Number of properties | property	4
Net rentable area (in square feet) | ft²	498,318