Acquisitions, Dispositions and New Construction - Additional Information (Detail)	1 Months Ended		2 Months Ended	3 Months Ended
	Mar. 31, 2016 USD ($) ft² Time	Feb. 28, 2015 USD ($) ft² Time Building	Feb. 28, 2015 USD ($) ft² Property Time	Mar. 31, 2016 USD ($) ft² Time	Mar. 31, 2015 USD ($)
Business Acquisitions And Dispositions [Line Items]
Net rentable area | ft²		16,000	16,000
Total purchase price		$ 4,100,000	$ 4,100,000
Maximum amount of investment for development and construction	$ 21,100,000			$ 21,100,000
Cash received for property exchange transaction				$ 0	$ 0
Number of Buildings purchased | Building		2
Mission and Weslaco Freestanding Emergency Departments
Business Acquisitions And Dispositions [Line Items]
Total purchase price		$ 12,800,000	$ 12,800,000
Number of real properties purchased | Property			2
Area of acquired building | ft²		13,600	13,600
Lease agreement period			10 years
Universal Health Services, Inc
Business Acquisitions And Dispositions [Line Items]
Number of term renewal options | Time	6			6
Additional renewal terms				5 years
Universal Health Services, Inc | Mission and Weslaco Freestanding Emergency Departments
Business Acquisitions And Dispositions [Line Items]
Number of term renewal options | Time		6	6
Additional renewal terms			5 years
Madison Professional Office Building
Business Acquisitions And Dispositions [Line Items]
Net rentable area | ft²	30,100			30,100
Renewal Term (years)	6 years 2 months 12 days
Total purchase price	$ 10,100,000			$ 10,100,000
Medical office buildings
Business Acquisitions And Dispositions [Line Items]
Lease term				6 years 2 months 12 days