Limited Liability Companies Accounted for Under Equity Method (Parenthetical) (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Equity Method Investments [Line Items]
Proceeds from Lines of Credit		$ 59,350,000	$ 52,400,000
Brunswick Associates
Schedule Of Equity Method Investments [Line Items]
Third-party term loan		8,600,000
Arlington Medical Properties
Schedule Of Equity Method Investments [Line Items]
Committed investment in equity and debt financing, funded		5,200,000
Commitment to investment		$ 623,000
Proceeds from Lines of Credit	$ 22,800,000
Loan interest rate fixed percentage		5.29%
Maturity date		2018-01
Percentage of minority ownership purchased from third-party members		10.00%
Business acquisition additional consideration		$ 4,800,000
Cash payment made purchased addition of ownership interest		85.00%
Grayson Properties
Schedule Of Equity Method Investments [Line Items]
Third-party term loan		$ 14,400,000
Committed investment in equity and debt financing, funded		2,800,000
Commitment to investment		149,000
FTX MOB Phase II limited partnership
Schedule Of Equity Method Investments [Line Items]
Third-party term loan		5,300,000
Commitment to investment		2,500,000
Additional commitment to investment		$ 369,000