Quarterly report pursuant to Section 13 or 15(d)

Selected Balance Sheet Data - Additional Information (Detail)

v3.3.0.814
Selected Balance Sheet Data - Additional Information (Detail) - USD ($)
 3 Months Ended 9 Months Ended 12 Months Ended
Jan. 01, 2015
Jan. 01, 2014
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Dec. 31, 2014
Mar. 31, 2013
Schedule Of Accrued Expenses [Line Items]                
SARs frozen liability amount     $ 21,184,000   $ 21,184,000   $ 20,542,000  
Interest expense     380,000 $ 397,000 $ 1,349,000 $ 1,202,000    
Stock appreciation rights liability distribution           412,000    
Maximum payment deferral period for certain commissions payable         3 years      
Fair value of deferred compensation plan assets         110.00%      
SARs [Member]                
Schedule Of Accrued Expenses [Line Items]                
SARs frozen liability amount               $ 20,000,000
SARs liability frozen value date         Mar. 31, 2013      
SARs liability interest accrual commencement date         Jan. 01, 2014      
Interest expense     $ 214,000 $ 236,000 $ 642,000 $ 738,000    
Treasury note term   10 years            
Base spread on SARs liability variable rate   2.00%            
SARs liability interest accrual rate 4.173% 5.03%            
Stock appreciation rights liability distribution             $ 412,000