Limited Liability Companies Accounted for Under Equity Method (Parenthetical) (Detail) $ in Millions	Sep. 30, 2018 USD ($)
Brunswick Associates
Schedule Of Equity Method Investments [Line Items]
Third-party term loan	$ 8.3
Grayson Properties
Schedule Of Equity Method Investments [Line Items]
Third-party term loan	14.0
FTX MOB Phase II limited partnership
Schedule Of Equity Method Investments [Line Items]
Third-party term loan	5.1
Committed investment in equity and debt financing, funded	2.1
Commitment to investment	$ 2.5