Quarterly report pursuant to Section 13 or 15(d)

Notes Receivable from Partners - Additional Information (Detail)

v3.3.0.814
Notes Receivable from Partners - Additional Information (Detail) - Partners - USD ($)
9 Months Ended
Sep. 30, 2015
Dec. 31, 2014
Dec. 31, 2013
Aug. 31, 2009
Jan. 31, 2008
Related Party Transaction [Line Items]          
Term of promissory notes receivable in the form of five or six year interest-bearing promissory notes and/or in the form of nine year interest-bearing limited recourse promissory notes        
Notes receivable from partners $ 2,781,000 $ 3,212,000 $ 3,052,000    
Allowance for credit losses on notes receivable 0 0      
Limited Recourse          
Related Party Transaction [Line Items]          
Interest rates of promissory notes       2.77% 3.53%
Notes receivable from partners 1,213,000 1,300,000      
Full Recourse          
Related Party Transaction [Line Items]          
Notes receivable from partners $ 1,568,000 $ 1,912,000