Mortgage Notes Payable - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Interest expense capitalized	$ 2,704	$ 3,751	$ 7,557	$ 12,752
Fair value of mortgage notes payable	4,357,015		4,357,015		$ 4,082,448
Green Acres Commons
Debt Instrument [Line Items]
Recourse mortgage notes	$ 65,000		$ 65,000