Investments in Partially Owned Entities (Urban Edge Properties and PREIT Associates L.P.) (Details) $ / shares in Units, $ in Thousands	Mar. 31, 2017 USD ($) $ / shares shares
Urban Edge Properties
Schedule Of Equity Method Investments
Ownership common shares, investee (in shares) | shares	5,717,184
Equity method ownership percentage	5.40%
Closing share price (in dollars per share) | $ / shares	$ 26.3
Equity Method Investment fair Value	$ 150,362
Excess of investee's fair value over carrying amount	$ 126,004
PREIT
Schedule Of Equity Method Investments
Ownership common shares, investee (in shares) | shares	6,250,000
Equity method ownership percentage	8.00%
Closing share price (in dollars per share) | $ / shares	$ 15.14
Equity Method Investment fair Value	$ 94,625
Excess of investee's carrying amount over fair value	25,018
Excess of investee's carrying amount over equity in net assets	$ 68,845