REAL ESTATE - Properties Represented More than 10% of Company’s Total Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($) ft² $ / ft²
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	7,800,000
Total Real Estate, Net	$ 2,031,345
Percentage of Total Assets	30.50%
Annualized Base Rent	$ 71,917
Occupancy	88.00%
Accenture Tower | Assets, Total
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	1,457,724
Total Real Estate, Net	$ 358,198
Percentage of Total Assets	13.60%
Annualized Base Rent	$ 32,832
Average Annualized Base Rent per sq. ft. | $ / ft²	27.88
Occupancy	80.80%