REVENUE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,813,472	$ 1,591,194	$ 1,411,979
Financial Services
Disaggregation of Revenue [Line Items]
Total revenue	1,362,539	1,160,686	1,010,068
Benefits and Insurance Services
Disaggregation of Revenue [Line Items]
Total revenue	401,048	382,605	358,007
National Practices
Disaggregation of Revenue [Line Items]
Total revenue	49,885	47,903	43,904
Accounting, tax, advisory and consulting
Disaggregation of Revenue [Line Items]
Total revenue	1,362,539	1,160,686	1,010,068
Accounting, tax, advisory and consulting | Financial Services
Disaggregation of Revenue [Line Items]
Total revenue	1,362,539	1,160,686	1,010,068
Core Benefits and Insurance Services
Disaggregation of Revenue [Line Items]
Total revenue	383,550	365,848	342,063
Core Benefits and Insurance Services | Benefits and Insurance Services
Disaggregation of Revenue [Line Items]
Total revenue	383,550	365,848	342,063
Non-core Benefits and Insurance Services
Disaggregation of Revenue [Line Items]
Total revenue	17,498	16,757	15,944
Non-core Benefits and Insurance Services | Benefits and Insurance Services
Disaggregation of Revenue [Line Items]
Total revenue	17,498	16,757	15,944
Managed networking, hardware services
Disaggregation of Revenue [Line Items]
Total revenue	41,526	36,984	33,503
Managed networking, hardware services | National Practices
Disaggregation of Revenue [Line Items]
Total revenue	41,526	36,984	33,503
National Practices consulting
Disaggregation of Revenue [Line Items]
Total revenue	8,359	10,919	10,401
National Practices consulting | National Practices
Disaggregation of Revenue [Line Items]
Total revenue	$ 8,359	$ 10,919	$ 10,401