Related Party Transactions - Schedule of fees charged to unconsolidated joint ventures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Management fees
Related Party Transaction [Line Items]
Management fees	$ 40,709	$ 43,480	$ 43,394
Unconsolidated joint ventures and third party managed properties
Related Party Transaction [Line Items]
Management fees	34,804	34,164	34,663
Unconsolidated joint ventures and third party managed properties | Management fees
Related Party Transaction [Line Items]
Management fees	18,748	19,752	19,105
Unconsolidated joint ventures and third party managed properties | Development and leasing fees
Related Party Transaction [Line Items]
Management fees	$ 16,056	$ 14,412	$ 15,558