Real Estate and Lending Activities - Summary of Status on Current Development Projects (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Business Acquisition [Line Items]
Commitment	$ 92,105
Costs Incurred as of March 31, 2020	71,473
Circle [Member] | Birmingham, England [Member]
Business Acquisition [Line Items]
Commitment	44,531
Costs Incurred as of March 31, 2020	$ 41,207
Estimated Rent Commencement Date	3Q 2020
Circle Rehabilitation [Member] | Birmingham, England [Member]
Business Acquisition [Line Items]
Commitment	$ 20,074
Costs Incurred as of March 31, 2020	$ 17,097
Estimated Rent Commencement Date	3Q 2020
NeuroPsychiatric Hospitals [Member] | Houston, Texas [Member]
Business Acquisition [Line Items]
Commitment	$ 27,500
Costs Incurred as of March 31, 2020	$ 13,169
Estimated Rent Commencement Date	4Q 2020