NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets
Goodwill impairment charge	$ 6.0	$ 112.8	$ 11.1		$ 118.8	$ 11.1
Goodwill impairment charges non-tax deductible		111.0
Impairment charge		$ 85.6	11.1
INCOME TAXES
Uncertain tax positions	$ 0.0		$ 0.0		$ 0.0	$ 0.0
Customer relationships
Goodwill and Intangible Assets
Estimated useful lives					9 years 8 months 12 days	10 years 4 months 24 days
Customer relationships | Minimum
Goodwill and Intangible Assets
Estimated useful lives					10 years
Customer relationships | Maximum
Goodwill and Intangible Assets
Estimated useful lives					15 years
Non-compete agreements
Goodwill and Intangible Assets
Estimated useful lives					2 years 8 months 12 days	3 years
Non-compete agreements | Minimum
Goodwill and Intangible Assets
Estimated useful lives					2 years
Non-compete agreements | Maximum
Goodwill and Intangible Assets
Estimated useful lives					5 years
Trade names
Goodwill and Intangible Assets
Impairment charge				$ 2.8