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Accounting Policies (Tables) | 6 Months Ended
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Jun. 30, 2025
Accounting Policies [Abstract] |
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:
| Six Months Ended June 30,
(in millions) | 2025 |  | 2024
Beginning balance, January 1, | $ | 204 |  |  | $ | 220 |
Accrued claims, net | 32 |  |  | 31 |
Present value discount, net of accretion | (6) |  |  | (7) |
Paid claims | (41) |  |  | (33) |
Ending balance | $ | 189 |  |  | $ | 211 |
Current portion of accrued claims | $ | 76 |  |  | $ | 65 |
Long-term portion of accrued claims | 113 |  |  | 146 |
Total accrued claims | $ | 189 |  |  | $ | 211 |
Disaggregation of Revenue [Table Text Block] | Our revenue for our PEO HR Solutions by geographic region and for our other products and services offerings are as follows:
| Three Months Ended June 30, |  | Six Months Ended June 30,
(in millions) | 2025 | 2024 | % Change |  | 2025 | 2024 | % Change
Northeast | $ | 452 |  | $ | 437 |  | 3 | % |  | $ | 978 |  | $ | 946 |  | 3 | %
Southeast | 238 |  | 225 |  | 6 | % |  | 495 |  | 471 |  | 5 | %
Central | 301 |  | 292 |  | 3 | % |  | 636 |  | 616 |  | 3 | %
Southwest | 311 |  | 304 |  | 2 | % |  | 658 |  | 644 |  | 2 | %
West | 339 |  | 329 |  | 3 | % |  | 716 |  | 695 |  | 3 | %
| 1,641 |  | 1,587 |  | 3 | % |  | 3,483 |  | 3,372 |  | 3 | %
Other revenue | 17 |  | 18 |  | (6) | % |  | 38 |  | 35 |  | 9 | %
Total revenue | $ | 1,658 |  | $ | 1,605 |  | 3 | % |  | $ | 3,521 |  | $ | 3,407 |  | 3 | %
Revenues Comprise of Gross Billings and WSEE Payroll Cost [Table] | Revenues are comprised of gross billings less WSEE payroll costs as follows:
| Three Months Ended June 30, |  | Six Months Ended June 30,
(in millions) | 2025 | 2024 |  | 2025 | 2024
Gross billings | $ | 10,558 |  | $ | 10,361 |  |  | $ | 22,702 |  | $ | 21,844 |
Less: WSEE payroll cost | 8,900 |  | 8,756 |  |  | 19,181 |  | 18,437 |
Revenues | $ | 1,658 |  | $ | 1,605 |  |  | $ | 3,521 |  | $ | 3,407 |

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- Definition Tabular disclosure of disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-5 + Details
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