| Cover Cover | Feb. 16, 2021 |
| Cover [Abstract] | |
| Entity File Number | 001-36373 |
| Entity Tax Identification Number | 95-3359658 |
| Entity Address, Postal Zip Code | 94568 |
| City Area Code | 510 |
| Local Phone Number | 352-5000 |
| Document Type | 8-K |
| Document Period End Date | Feb. 16, 2021 |
| Entity Registrant Name | TRINET GROUP, INC. |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | Common stock par value $0.000025 per share |
| Pre-commencement Issuer Tender Offer | false |
| Pre-commencement Tender Offer | false |
| Written Communications | false |
| Soliciting Material | false |
| Entity Incorporation, State or Country Code | DE |
| Trading Symbol | TNET |
| Security Exchange Name | NYSE |
| Entity Address, Address Line One | One Park Place, Suite 600 |
| Entity Address, City or Town | Dublin, |
| Entity Address, State or Province | CA |
| Cover Non-printing | Feb. 16, 2021 |
| Cover [Abstract] | |
| Entity Central Index Key | 0000937098 |
| Amendment Flag | false |
| No Trading Symbol Flag |
