ACCOUNTS AND OTHER RECEIVABLES - Components of Accounts and Other Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Current
Trade accounts receivable	$ 604.7	$ 526.1
Trade notes receivable	1.8	1.0
Total trade receivables	606.5	527.1
Other notes receivable	0.0	0.0
Insurance receivables	1.5	43.0
Taxes receivable, including income taxes	12.3	15.0
Other receivables	11.0	14.8
Subtotal other receivables	24.8	72.8
Total trade and other receivables	631.3	599.9
Allowance for doubtful accounts, Current
Trade accounts receivable	(5.8)	(4.7)
Trade notes receivable	0.0	(0.1)
Total trade receivables	(5.8)	(4.8)
Other notes receivable	0.0	0.0
Total allowance for doubtful accounts	(5.8)	(4.8)
Total receivables, net	625.5	595.1
Long-term
Trade accounts receivable	0.0	0.0
Trade notes receivable	1.7	1.2
Total trade receivables	1.7	1.2
Other notes receivable	24.7	24.7
Insurance receivables	0.0	0.0
Taxes receivable, including income taxes	0.0	0.0
Other receivables	0.0	0.0
Subtotal other receivables	24.7	24.7
Total trade and other receivables	26.4	25.9
Allowance for doubtful accounts, Long-term
Trade accounts receivable	0.0	0.0
Trade notes receivable	0.0	(0.1)
Total trade receivables	0.0	(0.1)
Other notes receivable	0.0	0.0
Total allowance for doubtful accounts	0.0	(0.1)
Total net receivables	$ 26.4	$ 25.8