Investment and Disposition Activity - Narrative (Details) $ in Thousands		3 Months Ended	9 Months Ended
	Sep. 27, 2019 USD ($)	Sep. 30, 2019 USD ($) construction_loan states healthcareproperty mezzanine_loan buyouts	Sep. 30, 2019 USD ($) construction_loan states healthcareproperty mezzanine_loan buyouts	Sep. 30, 2018 USD ($)
Noncash or Part Noncash Acquisitions [Line Items]
Building and improvements			$ 90,555	$ 242,827
Long-term debt			39,001	$ 2,000
Consideration transferred	$ 34,600	$ 95,184	$ 1,100
Number of noncontrolling interest buyouts | buyouts		2	2
Payments for loans receivable and payments to acquire real estate		$ 152,800	$ 152,800
Construction Loans
Noncash or Part Noncash Acquisitions [Line Items]
Notes receivable, face amount		$ 44,300	$ 44,300
Number of mezzanine loans collateralized | construction_loan		2	2
Long-term debt			$ 14,100
Real Estate Loan
Noncash or Part Noncash Acquisitions [Line Items]
Number of mezzanine loans collateralized | mezzanine_loan		4	4
Long-term debt			$ 17,900
Term Loan
Noncash or Part Noncash Acquisitions [Line Items]
Notes receivable, face amount		$ 7,000	$ 7,000
Number of mezzanine loans collateralized | construction_loan		1	1
Two Healthcare Properties Acquired in 2019
Noncash or Part Noncash Acquisitions [Line Items]
Number of operating healthcare properties | healthcareproperty		10	10
Number of states in which operating healthcare properties and land parcel located | states		4	4
Asset acquisition, consideration transferred			$ 105,200
Building and improvements			4,300
Loan Investments
Noncash or Part Noncash Acquisitions [Line Items]
Notes receivable, face amount		$ 39,000	$ 39,000
Consideration transferred		$ 11,945
Earn-out Investments
Noncash or Part Noncash Acquisitions [Line Items]
Number of operating healthcare properties | healthcareproperty		2	2
Consideration transferred			$ 3,200