Limited Liability Companies Accounted for Under Equity Method (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2022
Brunswick Associates
Schedule Of Equity Method Investments [Line Items]
Third-party term loan		$ 8.9
Grayson Properties Member | Denison Texas
Schedule Of Equity Method Investments [Line Items]
Commitment to investment		1.8
FTX MOB Phase II limited partnership
Schedule Of Equity Method Investments [Line Items]
Member loan used to repay mortgage loan	$ 3.5
Repayment of loan	$ 4.7
Grayson Properties II LP
Schedule Of Equity Method Investments [Line Items]
Construction loan		13.1
Construction loan outstanding balance		13.1
Grayson Properties II LP | Maximum | Denison Texas
Schedule Of Equity Method Investments [Line Items]
Commitment to investment		$ 4.8