Condensed Combined Balance Sheets for LLCs/LPs Accounted Under Equity Method (Parenthetical) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Right-of-use land assets	$ 8,891	$ 8,914
Right-of-use land liabilities	8,891	8,914
Limited Liability Companies
Schedule Of Equity Method Investments [Line Items]
Right-of-use land assets	4,300	4,300
Right-of-use land liabilities	$ 4,300	$ 4,300
FTX MOB Phase II limited partnership
Schedule Of Equity Method Investments [Line Items]
Debt Instrument Maturity Date	2023-03