Debt - Schedule of Company's Outstanding Debt (Parenthetical) (Detail)			3 Months Ended
	Aug. 31, 2018	Feb. 23, 2018 Loan	Mar. 31, 2019 Property Loan
Freddie Mac Utah Loans [Member]
Debt Instrument [Line Items]
Debt instrument, interest payment period		2 years	2 years
Amortization period		30 years	30 years
Number of mortgage loans | Loan		3	3
Number of senior housing properties acquired | Property			3
Courtyard Freddie Mac Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument, interest payment period	4 years		4 years
Amortization period	30 years		30 years
Courtyard Delayed Draw Commitment [Member]
Debt Instrument [Line Items]
Commitment fee percentage on loan principal outstanding			0.50%
Courtyard Initial Bridge Loan [Member]
Debt Instrument [Line Items]
Commitment fee percentage on loan principal outstanding			0.50%