Mortgage Notes Payable - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Interest expense capitalized	$ 2,143	$ 4,670	$ 4,853	$ 9,001
Fair value of mortgage notes payable	4,372,627		4,372,627		$ 4,082,448
Green Acres Commons
Debt Instrument [Line Items]
Recourse mortgage notes	$ 65,000		$ 65,000