Condensed Consolidating Financial Information - Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net cash provided by (used in) operating activities	$ 34.6	$ (21.5)
Net cash provided by (used in) investing activities
Purchase of property, plant and equipment	(6.0)	(10.6)
Proceeds from sale of joint venture	0.1
Intercompany transactions	0.0	0.0
Net cash provided by (used in) investing activities	(5.9)	(10.6)
Net cash provided by (used in) financing activities
Repayments on term loan	(5.0)	0.0
Borrowings under revolving credit facilities	121.8	169.6
Repayments under revolving credit facilities	(35.8)	(157.6)
Debt issuance costs		3.4
Intercompany transactions	0.0	0.0
Net cash provided by (used in) financing activities	81.0	15.4
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	109.7	(16.7)
Cash, cash equivalents and restricted cash, beginning of period	39.7	39.7
Cash, cash equivalents and restricted cash, end of period	149.4	23.0
Consolidating Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net cash provided by (used in) operating activities	0.0	0.0
Net cash provided by (used in) investing activities
Purchase of property, plant and equipment	0.0	0.0
Proceeds from sale of joint venture	0.0
Intercompany transactions	(1.0)	32.8
Net cash provided by (used in) investing activities	(1.0)	32.8
Net cash provided by (used in) financing activities
Repayments on term loan	0.0
Borrowings under revolving credit facilities	0.0	0.0
Repayments under revolving credit facilities	0.0	0.0
Debt issuance costs		0.0
Intercompany transactions	1.0	(32.8)
Net cash provided by (used in) financing activities	1.0	(32.8)
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	0.0	0.0
Cash, cash equivalents and restricted cash, beginning of period	0.0	0.0
Cash, cash equivalents and restricted cash, end of period	0.0	0.0
The Company [Member] \| Reportable Legal Entities [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net cash provided by (used in) operating activities	(13.0)	(17.6)
Net cash provided by (used in) investing activities
Purchase of property, plant and equipment	(0.1)	(0.6)
Proceeds from sale of joint venture	0.0
Intercompany transactions	30.5	(15.2)
Net cash provided by (used in) investing activities	30.4	(15.8)
Net cash provided by (used in) financing activities
Repayments on term loan	(5.0)
Borrowings under revolving credit facilities	76.8	169.6
Repayments under revolving credit facilities	(35.8)	(157.6)
Debt issuance costs		3.4
Intercompany transactions	28.9	17.8
Net cash provided by (used in) financing activities	64.9	33.2
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	82.3	(0.2)
Cash, cash equivalents and restricted cash, beginning of period	0.2	0.1
Cash, cash equivalents and restricted cash, end of period	82.5	(0.1)
Combined Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net cash provided by (used in) operating activities	34.1	(5.3)
Net cash provided by (used in) investing activities
Purchase of property, plant and equipment	(5.6)	(6.8)
Proceeds from sale of joint venture	0.0
Intercompany transactions	(29.4)	(17.7)
Net cash provided by (used in) investing activities	(35.0)	(24.5)
Net cash provided by (used in) financing activities
Repayments on term loan	0.0
Borrowings under revolving credit facilities	0.0	0.0
Repayments under revolving credit facilities	0.0	0.0
Debt issuance costs		0.0
Intercompany transactions	1.9	29.9
Net cash provided by (used in) financing activities	1.9	29.9
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	1.0	0.1
Cash, cash equivalents and restricted cash, beginning of period	1.0	0.8
Cash, cash equivalents and restricted cash, end of period	2.0	0.9
Combined Non-Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net cash provided by (used in) operating activities	13.5	1.4
Net cash provided by (used in) investing activities
Purchase of property, plant and equipment	(0.3)	(3.2)
Proceeds from sale of joint venture	0.1
Intercompany transactions	(0.1)	0.1
Net cash provided by (used in) investing activities	(0.3)	(3.1)
Net cash provided by (used in) financing activities
Repayments on term loan	0.0
Borrowings under revolving credit facilities	45.0	0.0
Repayments under revolving credit facilities	0.0	0.0
Debt issuance costs		0.0
Intercompany transactions	(31.8)	(14.9)
Net cash provided by (used in) financing activities	13.2	(14.9)
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	26.4	(16.6)
Cash, cash equivalents and restricted cash, beginning of period	38.5	38.8
Cash, cash equivalents and restricted cash, end of period	$ 64.9	$ 22.2

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