Real Estate Activities - Concentration of Credit Risks and Related Party Transactions - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) Investment	Dec. 31, 2018 USD ($) Investment	Dec. 31, 2017 USD ($)
Related Party Transactions [Member]
Business Acquisition [Line Items]
Lease and interest revenue earned from tenants | $	$ 451.1	$ 501.4	$ 422.4
Total Gross Assets [Member] | Geographic Concentration [Member] | U.S. [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	74.00%	80.00%
Total Gross Assets [Member] | Geographic Concentration [Member] | Europe [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	20.00%	20.00%
Total Gross Assets [Member] | Geographic Concentration [Member] | Australia [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	6.00%
Total Gross Assets [Member] | Geographic Concentration [Member] | Steward Health Care System LLC [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	24.00%	38.00%
Revenue [Member] | Customer Concentration Risk [Member] | General Acute Care Hospital and Healthcare System [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	87.00%	76.00%
Revenue [Member] | Customer Concentration Risk [Member] | Rehabilitation Hospital with Covenant Health System [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	10.00%	20.00%
Revenue [Member] | Customer Concentration Risk [Member] | Long-term Acute Care Hospital [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	3.00%	4.00%
Revenue [Member] | Credit Concentration Risk [Member] | Steward Health Care System LLC [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	42.00%	39.00%
Revenue [Member] | Credit Concentration Risk [Member] | Prime [Member]
Business Acquisition [Line Items]
Percentage of concentration risk	15.00%	16.00%
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	2.60%	4.00%