v3.26.1
Basis of Presentation of Interim Period Statements - Additional Information (Detail)
3 Months Ended
Mar. 31, 2026
USD ($)
Segment
Company
shares
Mar. 31, 2025
USD ($)
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    
Cash and cash equivalents, maturity term 3 months    
Allowance for expected credit losses $ 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 $ 1,900,000 $ 2,400,000  
Payroll weekly payment term 30 days    
Unbilled receivables $ 284,700,000   241,500,000
Remaining trade accounts receivable $ 9,300,000   $ 7,500,000
Accrued payroll, payroll taxes and related benefits   187,000,000  
Operations related to accrued payroll and related benefits   (17,600,000)  
Payroll taxes   $ 169,400,000  
Potential common shares related to stock options, restricted stock units, performance share units, and employee stock purchase plan | shares 594,384 593,988  
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 30,000,000    
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 30,000,000    
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 30,000,000    
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 30,000,000    
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 $ 30,000,000