v3.26.1
Basis of Presentation of Interim Period Statements - Additional Information (Detail)
shares in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Company
shares
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2026
USD ($)
Company
Segment
shares
Jun. 30, 2025
USD ($)
shares
Dec. 31, 2025
USD ($)
Basis Of Presentation Of Interim Period Statements [Line Items]          
Revenue recognition professional employer service contracts term     1 year    
Professional employer service contract cancellation and termination period     30 days    
Payment term for staffing customers     30 days    
Number of wholly-owned insurance companies | Company 2   2    
Cash and cash equivalents, maturity term     3 months    
Allowance for expected credit losses $ 400,000   $ 400,000   $ 400,000
Number of operating segment | Segment     1    
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]     srt:ChiefExecutiveOfficerMember    
Interest income 1,981,000 $ 2,505,000 $ 3,889,000 $ 4,902,000  
Payroll weekly payment term     30 days    
Unbilled receivables $ 291,333,000   $ 291,333,000   $ 241,471,000
Accrued payroll, payroll taxes and related benefits   173,300,000   360,300,000  
Operations related to accrued payroll and related benefits   (18,300,000)   (35,900,000)  
Payroll taxes   $ 155,000,000   324,400,000  
Income taxes paid net of income tax refunds received     $ 1,200,000 $ 3,300,000  
Potential common shares related to stock options, restricted stock units, performance share units, and employee stock purchase plan | shares 257 35 974 35  
2024-2025 Policy [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum additional premiums charged amount for twelve month policy period, if claims develop adversely     $ 0    
2024-2025 Policy [Member] | Minimum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     20,000,000    
2024-2025 Policy [Member] | Maximum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     32,000,000    
2021-2022 Policy [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum additional premiums charged amount for twelve month policy period, if claims develop adversely     7,500,000    
2021-2022 Policy [Member] | Minimum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     20,000,000    
2021-2022 Policy [Member] | Maximum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     32,000,000    
2022-2023 Policy [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum additional premiums charged amount for twelve month policy period, if claims develop adversely     0    
2022-2023 Policy [Member] | Minimum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     20,000,000    
2022-2023 Policy [Member] | Maximum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     32,000,000    
2023-2024 Policy [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum additional premiums charged amount for twelve month policy period, if claims develop adversely     0    
2023-2024 Policy [Member] | Minimum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     20,000,000    
2023-2024 Policy [Member] | Maximum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     32,000,000    
2025-2026 Policy [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum additional premiums charged amount for twelve month policy period, if claims develop adversely     0    
2025-2026 Policy [Member] | Minimum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     20,000,000    
2025-2026 Policy [Member] | Maximum [Member]          
Basis Of Presentation Of Interim Period Statements [Line Items]          
Maximum savings amount for twelve month policy period, if claims develop favorably     $ 32,000,000