SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Estimated Useful Lives of Property and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 143.0	$ 134.2
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]	Useful Life, Shorter of Lease Term or Asset Utility [Member]
Equipment and Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 38.7	40.0
Equipment and Furniture [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	3 years
Equipment and Furniture [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	7 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 39.9	$ 43.4
Computer Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	2 years
Computer Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	7 years
Leased fleet and copiers
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]	Useful Life, Shorter of Lease Term or Asset Utility [Member]