Real Estate Transactions - Construction, Tenant, and Other Capital Improvements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Real estate acquisitions [Line Items]
Funding for construction, tenant and other capital improvements	$ 788,895	$ 677,274	$ 560,875
Life Science
Real estate acquisitions [Line Items]
Funding for construction, tenant and other capital improvements	573,999	499,956	396,431
Medical Office
Real estate acquisitions [Line Items]
Funding for construction, tenant and other capital improvements	173,672	146,466	146,087
CCRC
Real estate acquisitions [Line Items]
Funding for construction, tenant and other capital improvements	41,224	0	0
Other
Real estate acquisitions [Line Items]
Funding for construction, tenant and other capital improvements	$ 0	$ 30,852	$ 18,357