Real Estate Investments - Assets Held for Sale (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) ft² property	Dec. 31, 2016 property
Real Estate [Line Items]
Number of properties held for sale | property	3	2
PENNSYLVANIA | Inpatient Rehabilitation Facility
Real Estate [Line Items]
Area of real estate property held for sale	78,731
TEXAS | Inpatient Rehabilitation Facility
Real Estate [Line Items]
Area of real estate property held for sale	39,786
Expected gain on disposition | $	$ 8.5
ILLINOIS | Medical Office Building
Real Estate [Line Items]
Area of real estate property held for sale	5,100
Impairment charge | $	$ 0.3