Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 7,121,147	$ 6,828,739
Corporate Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	906,948	639,190
Same Store [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	4,592,960	4,669,022
Redevelopment and Development [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	826,200	716,750
Acquisition and Other Real Estate [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	$ 795,039	$ 803,777