Investments In And Advances To Unconsolidated Real Estate Joint Ventures (Condensed Statements Of Operations For Equity Method Joint Ventures) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 94,319	$ 245,693	$ 298,405	$ 463,045
Net income (loss)	(36,651)	(7,624)	(67,466)	(2,986)
Equity in net earnings of unconsolidated real estate joint venture	145	8,759	696	8,742
Altis At Lakeline - Austin Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Total revenues				1,459
Gain on sale of real estate		17,150		17,150
Other revenue		(25)		(1,773)
Net income (loss)		17,125		16,836
Equity in net earnings of unconsolidated real estate joint venture		5,256		5,029
PGA Design Center Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Total revenues	31		62
Gain on sale of real estate		7,212		7,212
Other expenses	(1)	(88)	(1)	(183)
Net income (loss)	30	7,124	61	7,029
Equity in net earnings of unconsolidated real estate joint venture	$ 12	$ 2,849	$ 24	$ 2,812