Real Estate Activities - Concentration of Credit Risks and Related Party Transactions - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) Investment	Dec. 31, 2019 USD ($) Investment	Dec. 31, 2018 USD ($)
Related Party Transactions [Member]
Business Acquisition [Line Items]
Lease and interest revenue earned from tenants | $	$ 29.8	$ 85.3	$ 102.2
Total Gross Assets [Member] | Geographic Concentration [Member] | U.S. [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	65.00%	74.00%
Total Gross Assets [Member] | Geographic Concentration [Member] | Europe [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	28.00%	20.00%
Total Gross Assets [Member] | Geographic Concentration [Member] | Australia [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	6.00%	6.00%
Total Gross Assets [Member] | Geographic Concentration [Member] | South America [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	1.00%
Revenue [Member] | Customer Concentration Risk [Member] | General Acute Care Hospital and Healthcare System [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	87.00%	82.00%
Revenue [Member] | Customer Concentration Risk [Member] | Rehabilitation Hospital with Covenant Health System [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	8.00%	10.00%
Revenue [Member] | Customer Concentration Risk [Member] | Freestanding ER/Urgent Care Facilities and Behavioral Health Facilities [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	2.00%	5.00%
Revenue [Member] | Customer Concentration Risk [Member] | Long-term Acute Care Hospital [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	3.00%	3.00%
Revenue [Member] | Credit Concentration Risk [Member] | Steward Health Care System LLC [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	30.00%	42.00%
Revenue [Member] | Credit Concentration Risk [Member] | Circle [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	13.00%
Revenue [Member] | Credit Concentration Risk [Member] | Circle [Member] | Maximum [Member]
Business Acquisition [Line Items]
Percentage of concentration risk		10.00%
Revenue [Member] | Credit Concentration Risk [Member] | Prospect [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	12.00%
Revenue [Member] | Credit Concentration Risk [Member] | Prospect [Member] | Maximum [Member]
Business Acquisition [Line Items]
Percentage of concentration risk		10.00%
Pro Forma [Member] | Total Gross Assets [Member] | Customer Concentration Risk [Member]
Business Acquisition [Line Items]
Number of investment in property | Investment	0	0
Maximum percentage of entity's assets invested on single property	4.00%	4.00%