Commitments and Contingencies - Construction Activity (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) ft²
Other Commitments [Line Items]
Approximate Square Feet | ft²	15,800,000
Medical Office Building Expansion | Memphis, Tennessee
Other Commitments [Line Items]
Approximate Square Feet | ft²	110,883
Medical Office Building | Memphis, Tennessee
Other Commitments [Line Items]
Construction Activity, Total Funding During the Period, Excluding Purchase of Land and Building	$ 1.5
Medical Office Building | Washington
Other Commitments [Line Items]
Approximate Square Feet | ft²	151,031
Total amount funded	$ 54.1
Estimated amount to complete project	10.0
Land and Building | Medical Office Building | Memphis, Tennessee
Other Commitments [Line Items]
Construction Activity, Total Funding During the Period	$ 8.7