EMPLOYEE BENEFITS - ACCUMULATED BENEFIT OBLIGATIONS (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 705.0	$ 730.8
Information for pension and OPEB plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	6.6	7.5
Fair value of plan assets	0.0	0.0
Information for pension plans with a projected benefit obligation in excess of plan assets
Projected benefit obligation	6.6	7.5
Fair value of plan assets	0.0	0.0
OPEB Benefits
Information for pension and OPEB plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	$ 11.1	$ 11.8