Investment and Disposition Activity - Narrative (Details) $ in Thousands		3 Months Ended	6 Months Ended
	May 06, 2019 USD ($)	Jun. 30, 2019 USD ($) construction_loan states healthcareproperty mezzanine_loan	Jun. 30, 2019 USD ($) construction_loan states healthcareproperty mezzanine_loan	Jun. 30, 2018 USD ($)
Noncash or Part Noncash Acquisitions [Line Items]
Building and improvements			$ 23,007	$ 157,322
Long-term debt			27,056	$ 2,000
Consideration transferred		$ 33,348
Payments for loans receivable and payments to acquire real estate		57,600	57,600
Construction Loans
Noncash or Part Noncash Acquisitions [Line Items]
Notes receivable, face amount		$ 44,300	44,300
Long-term debt			$ 10,300
Number of mezzanine loans collateralized | construction_loan		2	2
Real Estate Loan
Noncash or Part Noncash Acquisitions [Line Items]
Long-term debt			$ 16,800
Number of mezzanine loans collateralized | mezzanine_loan		3	3
Two Healthcare Properties Acquired in 2019
Noncash or Part Noncash Acquisitions [Line Items]
Number of operating healthcare properties | healthcareproperty		2	2
Number of states in which operating healthcare properties and land parcel located | states		2	2
Asset acquisition, consideration transferred			$ 23,300
Building and improvements			4,300
Loan Investments
Noncash or Part Noncash Acquisitions [Line Items]
Notes receivable, face amount		$ 27,100	$ 27,100
Consideration transferred		$ 7,028
Earn-out Investments
Noncash or Part Noncash Acquisitions [Line Items]
Number of operating healthcare properties | healthcareproperty		2	2
Consideration transferred		$ 2,468	$ 2,500
NCI Buyout - MN Portfolio
Noncash or Part Noncash Acquisitions [Line Items]
Consideration transferred	$ 540		$ 500