Real Estate Investments - Acquisitions (Details) - Real Estate Acquisitions [Member] $ in Millions					1 Months Ended		9 Months Ended
	Sep. 14, 2015 USD ($) ft² Bed	Sep. 01, 2015 USD ($) ft² Bed tenant	Jun. 26, 2015 USD ($) ft² Bed	Jan. 15, 2015 USD ($) ft² building Bed	Nov. 30, 2015 USD ($) ft² Bed	Oct. 31, 2015 USD ($) ft² Bed	Sep. 30, 2015 USD ($) ft²
Business Acquisition [Line Items]
Square footage | ft²							246,558
Purchase price							$ 87.8
Cash consideration							68.3
Real Estate							87.1
Purchase price credits							(0.6)
Other							0.1
Mortgage notes payable assumed							(18.9)
Fair value premium recorded upon acquisition							$ 0.5
Washington [Member]
Business Acquisition [Line Items]
Square footage | ft²		52,813	35,558
Purchase price		$ 28.0	$ 14.0
Cash consideration		18.6	4.4
Real Estate		27.8	13.8
Purchase price credits			(0.1)
Other		0.2	0.1
Mortgage notes payable assumed		(9.4)	(9.5)
Fair value premium recorded upon acquisition		$ 0.3	$ 0.2
Stated interest rate (percent)		5.00%	5.75%
Number of Beds | Bed		624	177
Percentage of medical office building leased		100.00%	93.00%
Number of Tenants Occupying Building | tenant		1
Percentage of property leased			69.00%
COLORADO
Business Acquisition [Line Items]
Square footage | ft²	47,508
Purchase price	$ 6.5
Cash consideration	6.3
Real Estate	6.3
Purchase price credits	$ (0.2)
Number of Beds | Bed	224
Percentage of property leased	73.00%
California [Member]
Business Acquisition [Line Items]
Purchase price				$ 39.3
Cash consideration				39.0
Real Estate				39.2
Purchase price credits				(0.3)
Other				$ (0.2)
Number of medical office buildings in health system | building				2
Percentage of medical office building leased				97.00%
Kaiser Permanente and Washington Hospital Healthcare System [Member] | California [Member]
Business Acquisition [Line Items]
Square footage | ft²				110,679
Percentage of property leased				59.00%
Kaiser Permanente [Member] | California [Member]
Business Acquisition [Line Items]
Number of Beds | Bed				106
Washington Hospital Healthcare System [Member] | California [Member]
Business Acquisition [Line Items]
Number of Beds | Bed				353
Subsequent Event [Member] | California [Member]
Business Acquisition [Line Items]
Square footage | ft²					99,942
Purchase price					$ 47.0
Cash consideration					$ 43.1
Percentage of medical office building leased					97.00%
Medical Office Building [Member] | Subsequent Event [Member] | Washington [Member]
Business Acquisition [Line Items]
Square footage | ft²						33,169
Purchase price						$ 8.8
Cash consideration						$ 7.5
Percentage of medical office building leased						100.00%
Office Building [Member] | Subsequent Event [Member] | Washington [Member]
Business Acquisition [Line Items]
Square footage | ft²						12,077
Tacoma General Hospital [Member] | Subsequent Event [Member] | Washington [Member]
Business Acquisition [Line Items]
Number of Beds | Bed						340
Sutter Health [Member] | Subsequent Event [Member] | California [Member]
Business Acquisition [Line Items]
Number of Beds | Bed					326