Real Estate Activities and Lending Activities - 2019 Activity - Additional Information (Detail) SFr in Millions, $ in Millions, $ in Millions							6 Months Ended
	Jun. 28, 2019 CHF (SFr)	Jun. 10, 2019 USD ($) Hospital RenewalOption	Jun. 06, 2019 AUD ($) Hospital	May 31, 2019 USD ($)	May 27, 2019 CHF (SFr) _Campus	Apr. 03, 2019	Jun. 30, 2019 USD ($) Hospital
Business Acquisition [Line Items]
Term of lease extension, years							5 years
Weighted average remaining lease term					23 years		32 years 1 month 6 days
Other Acquisitions [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | $							$ 80.0
Swiss Healthcare Real Estate Company Infracore S A [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | SFr					SFr 236.6
Swiss Healthcare Real Estate Company Infracore S A [Member] | Joint Venture Partner [Member]
Business Acquisition [Line Items]
Ownership interest in joint venture under the equity method					46.00%
Aevis Victoria SA [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | SFr	SFr 47.0
Ownership interest in joint venture under the cost method	4.90%
Community Hospital [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Hospital		7
Purchase price of acquisition | $				$ 40.0
Leases fixed escalations		5 years
Lease extension options, description							two five-year extension options
Existence of option to extend		true
Number of lease extension options | RenewalOption		2
Term of lease extension, years		5 years
Community Hospital [Member] | Saint Luke’s Health System [Member]
Business Acquisition [Line Items]
Term of lease		14 years
Community Hospital [Member] | Kansas [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Hospital		7
Purchase price of acquisition | $		$ 145.4
Hospital [Member] | Healthscope Limited [Member]
Business Acquisition [Line Items]
Term of lease			20 years
Fixed annual escalations			2.50%
Hospital [Member] | Australia [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Hospital			11
Purchase price of acquisition | $			$ 1,200.0
Stamp duties and registration fees | $			$ 66.6
Acute Care Campus [Member] | Swiss Healthcare Real Estate Company Infracore S A [Member]
Business Acquisition [Line Items]
Number of facilities acquired | _Campus					13
Additional Properties [Member] | Switzerland [Member] | Swiss Healthcare Real Estate Company Infracore S A [Member]
Business Acquisition [Line Items]
Number of facilities acquired | _Campus					2
Acute Care Hospital [Member] | Poole, England [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Hospital							2
Acute Care Hospital [Member] | Poole, England [Member] | BMI Healthcare [Member]
Business Acquisition [Line Items]
Term of lease						14 years
Fixed annual escalators percentage						2.50%
Inpatient Rehabilitation Hospital [Member] | Germany [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Hospital							1