Real Estate and Lending Activities - Adeptus Health Transition Properties - Additional Information (Detail) - Adeptus Health Transition Properties [Member]		1 Months Ended	9 Months Ended
	Nov. 05, 2019 Property	Jul. 31, 2019 Property	Sep. 30, 2019 Property Facility
Business Acquisition [Line Items]
Number of facilities transitioned			16
Number of properties sold		2
Number of transitioned facilities not re-leased | Facility			3
Percentage of investment in remaining transition facilities on total assets			0.10%
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of re-leased properties	11