Quarterly report pursuant to Section 13 or 15(d)

Debt - Additional Information (Detail)

v3.21.2
Debt - Additional Information (Detail)
3 Months Ended 9 Months Ended 12 Months Ended
Jul. 01, 2019
USD ($)
Jun. 24, 2013
USD ($)
Installment
Sep. 30, 2021
USD ($)
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
Sep. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Debt Instrument [Line Items]              
Outstanding borrowings under credit facility     $ 9,927,000   $ 9,927,000   $ 12,600,000
Interest expense including amortization of deferred financing fees     92,000 $ 120,000 294,000 $ 445,000  
City National Bank              
Debt Instrument [Line Items]              
Credit facility, borrowing capacity   $ 15,000,000.0          
Interest expense including amortization of deferred financing fees     90,000 $ 117,000 286,000 $ 437,000  
Accrued, unpaid interest         $ 27,000   0
Delayed Draw Term Loan | City National Bank              
Debt Instrument [Line Items]              
Credit facility, borrowing capacity $ 25,500,000 $ 7,500,000          
Credit facility maturity date Jul. 01, 2026       Jun. 24, 2025    
Credit facility, interest rate description         the higher of the prime rate plus a margin of 0.25 percentage points and 2.5% or (b) the LIBOR rate plus 2.75 percentage points, at the borrowers’ option    
Increased borrowing capacity under credit facility $ 18,000,000.0            
Credit facility draw date Jul. 01, 2024            
Variable rate notes issued for redemption of partners' interests, spread   2.75%          
Debt instrument variable interest rate basis         LIBOR    
Credit facility, number of installments | Installment   20          
Credit facility, frequency of installments         quarterly    
Outstanding borrowings under credit facility     9,900,000   $ 9,900,000   12,600,000
Delayed Draw Term Loan | City National Bank | Maximum              
Debt Instrument [Line Items]              
Variable rate notes issued for redemption of partners' interests, spread   0.25%          
Debt instrument variable interest rate basis         prime rate    
Delayed Draw Term Loan | City National Bank | Minimum              
Debt Instrument [Line Items]              
Credit facility, fixed interest rate   2.50%          
Borrowings Under Revolving Credit Agreement | City National Bank              
Debt Instrument [Line Items]              
Credit facility, borrowing capacity $ 10,000,000.0 $ 7,500,000          
Credit facility maturity date         Jun. 21, 2019    
Credit facility extended maturity date         Jun. 18, 2022    
Increased borrowing capacity under credit facility $ 2,500,000            
Debt covenant, restriction on change in control   30.00%          
Outstanding borrowings under credit facility     $ 0   $ 0   $ 0