Real Estate - Schedule of Construction in Progress (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Real Estate [Line Items]
Construction in progress	$ 74,476	$ 335,644
The Waycroft
Real Estate [Line Items]
Construction in progress	8,567	255,443
7316 Wisconsin Avenue
Real Estate [Line Items]
Construction in progress	49,629	44,638
Ashbrook Marketplace
Real Estate [Line Items]
Construction in progress	3,727	19,128
Other
Real Estate [Line Items]
Construction in progress	$ 12,553	$ 16,435