Segment Reporting - Schedule of Current Reportable Segments by Revenue (Details) - USD ($) $ in Millions |
6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Dec. 31, 2021 |
Jun. 30, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Segment Reporting Information [Line Items] | ||||
| Revenue | $ 1,554 | $ 1,361 | $ 2,728 | $ 2,552 |
| Employer Solutions | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 1,347 | 1,156 | 2,288 | 2,084 |
| Employer Solutions | Recurring | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 1,213 | 1,049 | 2,051 | 1,834 |
| Employer Solutions | Project | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 134 | 107 | 237 | 250 |
| Professional Services | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 186 | 184 | 368 | 285 |
| Professional Services | Recurring | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 65 | 60 | 108 | 56 |
| Professional Services | Project | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 121 | 124 | 260 | 229 |
| Hosted Business | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | $ 21 | $ 21 | $ 72 | $ 183 |