Quarterly report pursuant to Section 13 or 15(d)

Revolving Credit Facility and Long-Term Debt - Additional Information (Detail)

v3.19.3
Revolving Credit Facility and Long-Term Debt - Additional Information (Detail) - Agreement [Member] - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Jun. 30, 2018
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Sep. 30, 2019
Aug. 06, 2019
Aug. 05, 2019
Dec. 31, 2018
Line of Credit Facility [Line Items]                  
Credit facility borrowing used     $ 5,800,000     $ 5,800,000      
Line of credit facility commitment fee description           The Agreement also provides for an unused commitment fee of 0.375% per year on the average daily unused amount of the revolving credit line, as well as a fee of 1.75% of the face amount of each letter of credit reserved under the line of credit.      
Outstanding balance on term loan and revolving credit facility     $ 0     $ 0     $ 0
Ratio of restricted and unrestricted cash and investments to workers' compensation and safety incentive liabilities     100.00% 100.00% 100.00%        
Scenario Forecast [Member]                  
Line of Credit Facility [Line Items]                  
Ratio of restricted and unrestricted cash and investments to workers' compensation and safety incentive liabilities   100.00%              
Minimum [Member]                  
Line of Credit Facility [Line Items]                  
EBITDA     $ 30,000,000 $ 30,000,000 $ 30,000,000 30,000,000      
Minimum [Member] | Scenario Forecast [Member]                  
Line of Credit Facility [Line Items]                  
EBITDA   $ 30,000,000              
Maximum [Member]                  
Line of Credit Facility [Line Items]                  
Prohibition on incurring additional indebtedness without the prior approval of the Bank in purchase money financing           $ 1,000,000      
Revolving Credit Facility [Member]                  
Line of Credit Facility [Line Items]                  
Credit facility borrowing capacity             $ 33,000,000 $ 28,000,000  
Credit facility, expiration date           Jul. 01, 2022      
Unused commitment fee on unused amount during period           0.375%      
Revolving Credit Facility [Member] | Daily Floating Rate [Member]                  
Line of Credit Facility [Line Items]                  
Term loan from Bank, Interest rate description           the daily floating rate of one month LIBOR plus 1.75%      
LIBOR plus rate           1.75%      
Revolving Credit Facility [Member] | Fixed Rate [Member]                  
Line of Credit Facility [Line Items]                  
Term loan from Bank, Interest rate description           the fixed rate of LIBOR plus 1.75%      
LIBOR plus rate           1.75%      
Standby Letters of Credit [Member]                  
Line of Credit Facility [Line Items]                  
Credit facility borrowing capacity             $ 8,000,000 $ 7,500,000  
Line of Credit [Member]                  
Line of Credit Facility [Line Items]                  
Unused commitment fee on unused amount           1.75%      
Chubb Letter of Credit [Member]                  
Line of Credit Facility [Line Items]                  
Credit facility borrowing capacity     $ 63,700,000     $ 63,700,000      
Credit facility, expiration date           Jul. 01, 2020      
Percentage of initial fee under letter of credit 2.50%         2.50%      
Percentage of aggregate fee under letter of credit           95.00%      
Percentage of annual fee under letter of credit     1.00%     1.00%      
Chubb Letter of Credit [Member] | Collateral Accounts [Member]                  
Line of Credit Facility [Line Items]                  
Percentage of deposit in collateral accounts           50.00%      
Deposit in collateral accounts     $ 18,100,000     $ 18,100,000      
Chubb Letter of Credit [Member] | Collateral Accounts [Member] | Minimum [Member]                  
Line of Credit Facility [Line Items]                  
Deposit in collateral accounts     16,000,000     $ 16,000,000      
Term Loan [Member]                  
Line of Credit Facility [Line Items]                  
Term loan from Bank, Interest rate description           one month LIBOR plus 2.0%      
Term loan with principal bank     $ 4,000,000     $ 4,000,000     $ 4,200,000
Payment of monthly principal of term loan           $ 18,375      
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]                  
Line of Credit Facility [Line Items]                  
LIBOR plus rate           2.00%