Commitments and Contingencies - Construction Activity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($) ft²	Mar. 31, 2020 ft²
Other Commitments [Line Items]
Approximate square feet | ft²	15,500,000
Medical office building expansion | Memphis, Tennessee
Other Commitments [Line Items]
Approximate square feet | ft²	110,883
Construction activity, total funding during the period, excluding purchase of land and building	$ 5,700
Medical office building | Washington
Other Commitments [Line Items]
Approximate square feet | ft²		151,031
Total amount funded	59,100
Estimated amount to complete project	5,000
Land and building | Medical office building | Memphis, Tennessee
Other Commitments [Line Items]
Construction activity, total funding during the period	$ 8,700