Real Estate Activities and Lending Activities - 2019 Activity - Additional Information (Detail) £ in Millions, SFr in Millions, $ in Millions											9 Months Ended
	Aug. 30, 2019 USD ($) Hospital RenewalOption	Aug. 23, 2019 USD ($) Hospital Health_Center RenewalOption	Aug. 16, 2019 GBP (£) Hospital	Jun. 28, 2019 CHF (SFr)	Jun. 10, 2019 USD ($) Hospital RenewalOption	Jun. 06, 2019 AUD ($) Hospital	May 27, 2019 CHF (SFr) _Campus	Apr. 12, 2019 Hospital	Apr. 03, 2019	Aug. 28, 2018 Hospital	Sep. 30, 2019 USD ($) Hospital	Dec. 31, 2018 USD ($)	Aug. 31, 2018
Business Acquisition [Line Items]
Purchase price of acquisition | $		$ 1,400,000,000
Mortgage loan balance | $											$ 3,180,580,000	$ 1,586,520,000
Term loan | $		$ 112,900,000
Additional number of businesses acquired		2
Performance thresholds achievement period		3 years
Term of lease extension, years											5 years
Weighted average remaining lease term							23 years				31 years 10 months 24 days
Other Acquisitions [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | $											$ 135,000,000
Vibra Healthcare, LLC [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | $	$ 254,000,000
Term of lease	20 years
Number of lease extension options | RenewalOption	3
Lease annual escalations percentage	2.00%
Lease extension options, description											three five-year extension options
Existence of option to extend	true
Term of lease extension, years	5 years
Ramsay Health Care [Member]
Business Acquisition [Line Items]
Term of lease			18 years
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%
Maximum [Member]
Business Acquisition [Line Items]
Term of lease											15 years
Future purchase price adjustment | $		$ 250,000,000.0
Minimum [Member]
Business Acquisition [Line Items]
Term of lease											10 years
Prospect Medical Holdings Inc [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | $		$ 1,550,000,000
Term of lease		15 years
Number of lease extension options | RenewalOption		3
Secure Income REIT [Member]
Business Acquisition [Line Items]
Purchase price of acquisition | £			£ 347
Secure Income REIT [Member] | England [Member]
Business Acquisition [Line Items]
Number of private hospitals acquired			8
Acute Care Campus [Member]
Business Acquisition [Line Items]
Number of facilities acquired		11
Acute Care Campus [Member] | Swiss Healthcare Real Estate Company Infracore S A [Member]
Business Acquisition [Line Items]
Number of facilities acquired | _Campus							13
Acute Care Campus [Member] | Prospect Medical Holdings Inc [Member]
Business Acquisition [Line Items]
Number of facilities acquired		14
Behavioral Health Care Facility [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Health_Center		2
Behavioral Health Care Facility [Member] | Prospect Medical Holdings Inc [Member]
Business Acquisition [Line Items]
Number of facilities acquired | Health_Center		2
Acute Care Hospital [Member]
Business Acquisition [Line Items]
Number of facilities acquired											3
Acute Care Hospital [Member] | Germany [Member]
Business Acquisition [Line Items]
Ownership interest in joint venture under the equity method													50.00%
Acute Care Hospital [Member] | Vibra Healthcare, LLC [Member]
Business Acquisition [Line Items]
Number of facilities acquired	7
Acute Care Hospital [Member] | Steward Health Care System LLC [Member] | Texas [Member]
Business Acquisition [Line Items]
Number of facilities acquired								1
Acute Care Hospital [Member] | BMI Healthcare [Member] | Poole, England [Member]
Business Acquisition [Line Items]
Number of facilities acquired											1
Term of lease									14 years
Fixed annual escalators percentage									2.50%
Acute Care Hospital [Member] | Halsen Healthcare [Member] | California [Member]
Business Acquisition [Line Items]
Number of facilities acquired											1
Acute Care Hospital [Member] | Mortgage Loans [Member]
Business Acquisition [Line Items]
Mortgage loan balance | $		$ 51,300,000
Inpatient Rehabilitation Hospital [Member] | Germany [Member]
Business Acquisition [Line Items]
Number of facilities acquired										3	1
Inpatient Rehabilitation Hospital [Member] | Vibra Healthcare, LLC [Member]
Business Acquisition [Line Items]
Number of facilities acquired	3
Community Hospital [Member]
Business Acquisition [Line Items]
Number of facilities acquired					7
Number of lease extension options | RenewalOption					2
Lease extension options, description											two five-year extension options
Existence of option to extend					true
Term of lease extension, years					5 years
Leases fixed escalations					5 years
Community Hospital [Member] | Kansas [Member]
Business Acquisition [Line Items]
Number of facilities acquired					7
Purchase price of acquisition | $					$ 145,400,000
Community Hospital [Member] | Saint Luke's Health System [Member]
Business Acquisition [Line Items]
Term of lease					14 years
Hospital [Member] | Australia [Member]
Business Acquisition [Line Items]
Number of facilities acquired						11
Purchase price of acquisition | $						$ 1,200.0
Stamp duties and registration fees | $						$ 66.6
Hospital [Member] | Healthscope Limited [Member]
Business Acquisition [Line Items]
Term of lease						20 years
Fixed annual escalations						2.50%
Additional Properties [Member] | Swiss Healthcare Real Estate Company Infracore S A [Member] | Switzerland [Member]
Business Acquisition [Line Items]
Number of facilities acquired | _Campus							2