Organization and Principles of Consolidation (Details)	9 Months Ended
	Sep. 30, 2018 retail_shopping_center
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Document Period End Date	Sep. 30, 2018
Operations commenced date	Dec. 31, 1993
Wholly Owned Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of Real Estate Properties	306
Unconsolidated Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of Real Estate Properties	120
Parent Company [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Ownership percentage of outstanding common partnership units	99.80%