GOODWILL AND INTANGIBLE ASSETS - Schedule of Goodwill And Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Schedule of Intangible Assets [Line Items]
Gross Asset Cost	$ 824.0	$ 830.3
Accumulated Amortization	358.6	339.6
Total	465.4	490.7
Customer lists
Schedule of Intangible Assets [Line Items]
Gross Asset Cost	775.2	781.1
Accumulated Amortization	331.7	313.7
Total	$ 443.5	467.4
Customer lists | Minimum
Schedule of Intangible Assets [Line Items]
Amortization Period	3 years
Customer lists | Maximum
Schedule of Intangible Assets [Line Items]
Amortization Period	20 years
Non-compete agreements
Schedule of Intangible Assets [Line Items]
Gross Asset Cost	$ 4.7	4.7
Accumulated Amortization	4.7	4.6
Total	$ 0.0	0.1
Non-compete agreements | Minimum
Schedule of Intangible Assets [Line Items]
Amortization Period	3 years
Non-compete agreements | Maximum
Schedule of Intangible Assets [Line Items]
Amortization Period	5 years
Intellectual property
Schedule of Intangible Assets [Line Items]
Amortization Period	10 years
Gross Asset Cost	$ 38.0	38.3
Accumulated Amortization	16.3	15.4
Total	21.7	22.9
Tradename
Schedule of Intangible Assets [Line Items]
Gross Asset Cost	6.1	6.2
Accumulated Amortization	5.9	5.9
Total	$ 0.2	$ 0.3
Tradename | Minimum
Schedule of Intangible Assets [Line Items]
Amortization Period	1 year
Tradename | Maximum
Schedule of Intangible Assets [Line Items]
Amortization Period	3 years