DESCRIPTION OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES - Assets and Liabilities of the Trust (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 251	$ 287
Restricted cash, cash equivalents and investments	780	1,269
Total current assets	2,605	2,578
Current liabilities:
Accrued wages	566	515
Payroll tax liabilities and other payroll withholdings	1,420	1,438
Total current liabilities	2,440	$ 2,463
TriNet Trust
Current assets:
Cash and cash equivalents	1
Restricted cash, cash equivalents and investments	81
Total current assets	82
Current liabilities:
Accrued wages	12
Payroll tax liabilities and other payroll withholdings	70
Total current liabilities	$ 82