LEASES - Lease Costs and Other Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
LEASES.
Operating lease costs	$ 7.6	$ 6.7	$ 22.8	$ 19.2
Weighted average remaining lease term (years)	10 years 4 months 24 days	11 years 2 months 12 days	10 years 4 months 24 days	11 years 2 months 12 days
Weighted average discount rate	3.10%	3.30%	3.10%	3.30%
Cash paid for amounts included in the measurement of lease liabilities	$ 5.0	$ 4.5	$ 15.8	$ 13.1
Right of use assets obtained in exchange for lease liabilities	$ 0.9	$ 3.3	$ 22.5	$ 14.0