Real Estate Transactions - Development Activities (Details) $ in Millions	1 Months Ended	9 Months Ended
	Oct. 31, 2019 property	Sep. 30, 2019 USD ($) property
Real Estate [Line Items]
Increase to development commitments | $		$ 56
Development commitments | $		$ 355
Medical office
Real Estate [Line Items]
Number of properties to be developed (in properties)		4
On-campus
Real Estate [Line Items]
Number of properties to be developed (in properties)		3
Subsequent Event | On-campus
Real Estate [Line Items]
Number of properties to be developed (in properties)	2