Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Revolving Credit Facility and Long-Term Debt - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2018
Dec. 31, 2020
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Jun. 30, 2019
Mar. 31, 2019
Jun. 30, 2020
May 15, 2020
May 14, 2020
Dec. 31, 2019
Line of Credit Facility [Line Items]                      
Cash dividends on common stock per share       $ 0.30 $ 0.30 $ 0.25 $ 0.25        
Agreement [Member]                      
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 0.50% 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
Maximum funded debt to EBITDA ratio       275.00% 275.00%            
Ratio of restricted and unrestricted cash and investments to workers' compensation and claim liabilities       115.00% 115.00%            
Cash dividends on common stock per share               $ 0.30      
Acquisition of shares of common stock employee tax withholding equity compensation arrangement               $ 3,500,000      
Agreement [Member] | Scenario Forecast [Member]                      
Line of Credit Facility [Line Items]                      
Maximum funded debt to EBITDA ratio   275.00% 275.00%                
Ratio of restricted and unrestricted cash and investments to workers' compensation and claim liabilities   115.00% 115.00%                
Agreement [Member] | 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      
Agreement [Member] | Revolving Credit Facility [Member]                      
Line of Credit Facility [Line Items]                      
Credit facility borrowing capacity                 $ 50,000,000.0 $ 33,000,000.0  
Credit facility, expiration date               Jul. 01, 2022      
Unused commitment fee on unused amount during period               0.50%      
Agreement [Member] | 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% or (b) the fixed rate of LIBOR plus 1.75%      
LIBOR plus rate               1.75%      
Agreement [Member] | 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%      
Agreement [Member] | Standby Letters of Credit [Member]                      
Line of Credit Facility [Line Items]                      
Credit facility borrowing capacity                 $ 8,000,000.0    
Agreement [Member] | Line of Credit [Member]                      
Line of Credit Facility [Line Items]                      
Unused commitment fee on unused amount               1.75%      
Agreement [Member] | 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, 2021      
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%      
Agreement [Member] | 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       $ 32,500,000       $ 32,500,000      
Agreement [Member] | 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      
Agreement [Member] | 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       $ 3,800,000       $ 3,800,000     $ 4,000,000.0
Payment of monthly principal of term loan               $ 18,375      
Agreement [Member] | Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]                      
Line of Credit Facility [Line Items]                      
LIBOR plus rate               2.00%