Fair Value of Financial Instruments - Equity Interest in Related Party and Related Loans Measured at Fair Value on Recurring Basis (Detail) - Fair Value Measurements, Recurring [Member] - Mortgage Loans [Member] $ in Thousands	Sep. 30, 2019 USD ($)
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	$ 115,000
Original Cost	$ 115,000