Real Estate Assets, Discontinued Operations and Assets Held for Sale (Table Illustration of Number of Properties in Discontinued Operations) (Details) - buildings	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Number of properties held for sale in discontinued operations	8
Number of properties sold in discontinued operations	73	0
Total number of properties in discontinued operations	81
Continuing Operations, Number of In-service Properties Held for Sale	2
Continuing Operations, Number of Real Estate Properties Sold	12	32
Continuing Operations, Number of Real Estate Properties Sold or Classified as Held for Sale	46
Number of Real Estate Properties Held for Sale	10
Number of Real Estate Properties Sold	85	32
Total Properties Sold or Classified as Held for Sale	127
Medical Office Portfolio Sale [Member]
Continuing Operations, Number of Real Estate Properties Sold	4
Total Properties Sold or Classified as Held for Sale	77