Real Estate Investments - Assets Held for Sale (Details) $ in Millions					3 Months Ended		9 Months Ended
	Sep. 07, 2017 USD ($)	Jun. 29, 2017 USD ($) ft²	Jun. 16, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2017 USD ($) ft² property	Mar. 31, 2017 USD ($)	Sep. 30, 2017 USD ($) ft² property	Dec. 31, 2016 property
Real Estate [Line Items]
Number of properties held for sale | property					1		1	2
Number of properties reclassified to held for sale | property							4
Number of properties sold | property							5
PENNSYLVANIA | Inpatient Rehabilitation Facility
Real Estate [Line Items]
Area of real estate property held for sale | ft²					78,731		78,731
TEXAS | Inpatient Rehabilitation Facility
Real Estate [Line Items]
Area of real estate property held for sale | ft²		39,786
ILLINOIS | Medical Office Building
Real Estate [Line Items]
Area of real estate property held for sale | ft²					5,100		5,100
Impairment charge						$ 0.3
Real Estate Dispositions
Real Estate [Line Items]
Gain/(Impairment)							$ 34.4
Real Estate Dispositions | TEXAS
Real Estate [Line Items]
Gain/(Impairment)		$ 8.3		$ 15.8
Real Estate Dispositions | ILLINOIS
Real Estate [Line Items]
Gain/(Impairment)			$ 0.0
Impairment charge						$ 0.3
Real Estate Dispositions | MISSOURI
Real Estate [Line Items]
Gain/(Impairment)	$ (5.1)				$ 5.1