Investment in Unconsolidated Joint Ventures - Narrative (Details) $ in Thousands, ft² in Millions	1 Months Ended			3 Months Ended		9 Months Ended
	Apr. 30, 2020	Mar. 31, 2020 USD ($) ft²	Feb. 29, 2020 USD ($) a	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Schedule of Equity Method Investments [Line Items]
Gross purchase price						$ 435,539	$ 58,968
Gain on sale of interest				$ (59)	$ 0	$ 45,940	$ 0
Gateway
Schedule of Equity Method Investments [Line Items]
Area of property | ft²		1.1
Gross purchase price		$ 52,200
Internal rate of return		17.00%
Gain on sale of interest		$ 44,600
Wildwood Associates
Schedule of Equity Method Investments [Line Items]
Gross purchase price			$ 900
Gain on sale of interest			$ 1,300
Area of land | a			6.3
Elimination of the remaining negative basis in the joint venture			$ 520
Carolina Square Holdings LP | LIBOR
Schedule of Equity Method Investments [Line Items]
Basis spread on variable rate (percent)	1.25%	1.90%