Acquisitions and Dispositions - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) parking_deck states healthcareproperty condominium_units	Jun. 30, 2016 USD ($)
Business Acquisition [Line Items]
Number of parking decks | parking_deck			1
Number of states in which operating healthcare properties and land parcel located | states			13
Buyout of redeemable noncontrolling interest			$ 2,800
Purchase price	$ 588,176		836,500
Real estate revenues	76,599	$ 53,216	153,265	$ 97,350
Net income	10,331	$ 7,184	17,047	$ 12,608
Loans
Business Acquisition [Line Items]
Mortgage loans on real estate, new mortgage loans			$ 8,600
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Number of operating healthcare properties | healthcareproperty			20
Number of condominium units | condominium_units			2
Payments to acquire businesses, gross			$ 825,100
Real estate revenues	5,500		7,300
Net income	$ 1,100		(1,700)
Closing costs			$ 4,400