OTHER CURRENT ASSETS (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
OTHER CURRENT ASSETS
Insurance	$ 12.0	$ 10.1
Licensing, permits and tolls	4.9	5.4
Other prepaids	3.2	1.7
Parts supplies	3.1	3.5
Income tax receivable	1.6
Highway and fuel taxes	1.1	1.6
Other current assets	0.6	3.1
Total	$ 26.5	$ 25.4