XML 47 R34.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)
9 Months Ended
Feb. 21, 2017
Sep. 30, 2016
Sep. 30, 2017
Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]        
Hedges or derivatives     $ 0 $ 0
Earn-out payment $ 2,400,000 $ 3,778,000    
Fair Value, Inputs, Level 3 [Member]        
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]        
Mortgage loans payable, fair value     $ 419,300,000 $ 323,700,000