REAL ESTATE - Properties Represented More than 10% of Company’s Total Assets (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($) ft² $ / ft²
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	7,500,000
Total Real Estate, Net	$ 1,934,562
Annualized Base Rent	$ 66,208
Occupancy	85.00%
Accenture Tower | Assets, Total
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	1,457,724
Total Real Estate, Net	$ 364,617
Annualized Base Rent	$ 28,726
Average Annualized Base Rent per sq. ft. | $ / ft²	26.54
Occupancy	74.20%
Accenture Tower | Assets, Total | Customer Concentration Risk
Real Estate Properties [Line Items]
Percentage of Total Assets	14.80%