Subsequent Events (Narrative) (Details)		1 Months Ended	6 Months Ended
	Jul. 27, 2016 USD ($)	Aug. 01, 2016 USD ($) property	Jun. 30, 2016 USD ($) property	Mar. 31, 2016 USD ($)
Subsequent Event [Line Items]
Number of acquired centers | property			1
Gross acquisition purchase price			$ 93,200,000
Debt, net			$ 1,871,510,000
Unsecured Debt [Member]
Subsequent Event [Line Items]
Debt payable				$ 200,000,000
Unsecured Debt [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt payable	$ 200,000,000
Debt, net		$ 0
Optional extension term	1 year
Florida Center [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Number of acquired centers | property		1
Gross acquisition purchase price		$ 285,000,000