Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 7,048,245	$ 6,828,739
Corporate Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	837,708	629,001
Same Store [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	4,643,371	4,679,211
Redevelopment and Development [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	731,811	694,188
Acquisition [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	102,217	89,405
Other Real Estate [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	$ 733,138	$ 736,934