Real Estate Investments - Acquisitions (Details) $ in Thousands													9 Months Ended
	Oct. 07, 2020 USD ($) ft²	Sep. 28, 2020 USD ($) ft²	Sep. 24, 2020 USD ($) ft²	Jul. 31, 2020 USD ($) ft²	Jul. 23, 2020 USD ($) ft²	Jul. 17, 2020 USD ($) ft²	Jul. 01, 2020 USD ($) ft²	Mar. 13, 2020 USD ($) ft²	Mar. 09, 2020 USD ($) ft² property	Feb. 25, 2020 USD ($) ft²	Feb. 13, 2020 USD ($) ft²	Jan. 03, 2020 USD ($) ft²	Sep. 30, 2020 USD ($) ft² land_parcel
Business Acquisition [Line Items]
Number of land parcels acquired | land_parcel													4
Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price													$ 210,200
Mortgage notes payable													(19,300)
Cash consideration													194,400
Real estate													215,700
Other													$ (2,000)
Square footage | ft²													568,587
Land Acquisition
Business Acquisition [Line Items]
Purchase price													$ 1,600
Mortgage notes payable													0
Cash consideration													1,700
Real estate													1,700
Other													$ 0
Square footage | ft²													0
Land Acquisition, Subsequently Disposed
Business Acquisition [Line Items]
Purchase price													$ 1,000
Mortgage notes payable													0
Cash consideration													1,100
Real estate													1,100
Other													$ 0
Square footage | ft²													0
Real Estate and Land Acquisitions
Business Acquisition [Line Items]
Purchase price													$ 212,800
Mortgage notes payable													(19,300)
Cash consideration													197,200
Real estate													218,500
Other													$ (2,000)
Square footage | ft²													568,587
Medical office building | Los Angeles, CA | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price		$ 14,000				$ 35,000						$ 42,000
Mortgage notes payable		0				0						(19,300)
Cash consideration		14,000				37,700						22,800
Real estate		13,900				37,700						42,400
Other		$ 100				$ 0						$ (300)
Square footage | ft²		24,252				49,785						86,986
Medical office building | Atlanta, GA | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price				$ 20,500							$ 12,000
Mortgage notes payable				0							0
Cash consideration				21,600							11,800
Real estate				21,300							12,100
Other				$ 300							$ (300)
Square footage | ft²				48,145							64,624
Medical office building | Raleigh, NC | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price										$ 6,300
Mortgage notes payable										0
Cash consideration										6,500
Real estate										6,500
Other										$ 0
Square footage | ft²										15,964
Medical office building | Colorado Springs, CO | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price									$ 8,200
Mortgage notes payable									0
Cash consideration									8,300
Real estate									8,600
Other									$ (300)
Square footage | ft²									34,210
Medical office building | Denver, CO | Total real estate acquisitions
Business Acquisition [Line Items]
Number of properties acquired | property									3
Purchase price								$ 33,500
Mortgage notes payable								0
Cash consideration								33,200
Real estate								34,000
Other								$ (800)
Square footage | ft²								136,994
Medical office building | San Diego, CA | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price							$ 16,700
Mortgage notes payable							0
Cash consideration							16,700
Real estate							16,900
Other							$ (200)
Square footage | ft²							46,083
Medical office building | Seattle, WA | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price					$ 11,000
Mortgage notes payable					0
Cash consideration					10,900
Real estate					11,300
Other					$ (400)
Square footage | ft²					21,309
Medical office building | Houston, TX | Total real estate acquisitions
Business Acquisition [Line Items]
Purchase price			$ 11,000
Mortgage notes payable			0
Cash consideration			10,900
Real estate			11,000
Other			$ (100)
Square footage | ft²			40,235
Subsequent event | Medical office building | Colorado Springs, CO
Business Acquisition [Line Items]
Purchase price	$ 8,900
Square footage | ft²	36,720