Acquisitions and Dispositions - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) states healthcareproperty land	Jun. 30, 2017 USD ($)
Business Acquisition [Line Items]
Number of land parcels | land			1
Payments to acquire businesses, gross			$ 170,700
Revenues	$ 106,989	$ 76,599	212,212	$ 153,265
Net income	12,062	$ 10,331	$ 23,394	$ 17,047
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Number of operating healthcare properties | healthcareproperty			3
Number of states in which operating healthcare properties and land parcel located | states			4
Payments to acquire businesses, gross			$ 179,100
Revenues	3,500		5,400
Net income	1,500		2,000
Redeemable Noncontrolling Interest Buyouts
Business Acquisition [Line Items]
Net income (loss) attributable to redeemable noncontrolling interest			6,400
Loan Investment
Business Acquisition [Line Items]
Purchase price			$ 2,000
HMG Medical Plaza
Business Acquisition [Line Items]
Purchase price	$ 71,300