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Accounting Policies (Tables) | 12 Months Ended
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Dec. 31, 2023
Accounting Policies [Abstract] |
Disaggregation of Revenue [Table Text Block] | Our revenue for our PEO HR Outsourcing Solutions by geographic region and for our other products and services offerings are as follows:
| Year Ended December 31,
(in thousands) | 2023 | 2022 | 2021
Northeast | $ | 1,756,884 |  | $ | 1,624,556 |  | $ | 1,390,156 |
Southeast | 906,712 |  | 796,219 |  | 630,342 |
Central | 1,170,491 |  | 1,045,043 |  | 867,914 |
Southwest | 1,249,922 |  | 1,163,088 |  | 993,747 |
West | 1,337,294 |  | 1,251,186 |  | 1,033,996 |
| 6,421,303 |  | 5,880,092 |  | 4,916,155 |
Other revenue | 64,568 |  | 58,726 |  | 56,915 |
Total revenue | $ | 6,485,871 |  | $ | 5,938,818 |  | $ | 4,973,070 |
Revenues Comprise of Gross Billings and WSEE Payroll Cost [Table] | Revenues are comprised of gross billings less WSEE payroll costs as follows:
| Year Ended December 31,
(in thousands) | 2023 | 2022 | 2021
Gross billings | $ | 43,141,366 |  | $ | 40,126,910 |  | $ | 33,318,693 |
Less: WSEE payroll cost | 36,655,495 |  | 34,188,092 |  | 28,345,623 |
Revenues | $ | 6,485,871 |  | $ | 5,938,818 |  | $ | 4,973,070 |
Property, Plant and Equipment [Table Text Block] | Property and equipment, net consisted of the following:
(in thousands) | December 31, 2023 | December 31, 2022
Land | $ | 6,215 |  | $ | 6,215 |
Buildings and improvements | 217,274 |  | 207,740 |
Computer hardware and software | 145,206 |  | 141,856 |
Software development costs | 137,337 |  | 123,967 |
Furniture, fixtures and other | 51,849 |  | 50,835 |
Property and equipment, gross | 557,881 |  | 530,613 |
Accumulated depreciation and amortization | (360,457) |  | (330,621) |
Property and equipment, net | $ | 197,424 |  | $ | 199,992 |
Depreciation, Depletion, and Amortization [Policy Text Block] | The estimated useful lives of property and equipment for purposes of computing depreciation are as follows:
| Useful Life
Buildings and improvements | 5 | — | 30 | years
Computer hardware and software | 2 | — | 5 | years
Software development costs | 3 | — | 5 | years
Furniture, fixtures and other | 5 | — | 7 | years
Activity and balances related to incurred but not paid workers' compensation claims | The following table provides the activity and balances related to incurred but not paid workers’ compensation claims:
| Year Ended December 31,
(in thousands) | 2023 |  | 2022
Beginning balance, January 1, | $ | 229,408 |  |  | $ | 239,623 |
Accrued claims | 61,720 |  |  | 49,121 |
Present value discount, net of accretion | (13,430) |  |  | (9,517) |
Paid claims | (57,443) |  |  | (49,819) |
Ending balance | $ | 220,255 |  |  | $ | 229,408 |
Current portion of accrued claims | $ | 57,403 |  |  | $ | 49,779 |
Long-term portion of accrued claims | 162,852 |  |  | 179,629 |
Total accrued claims | $ | 220,255 |  |  | $ | 229,408 |

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