Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Statement of Cash Flows [Abstract]
Net earnings (loss)	$ 10.2	$ (12.4)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	41.9	47.4
Impairment charges	0.8	3.8
Amortization of debt issuance costs and original issue discount	0.6	0.6
Gain on debt extinguishment	0.0	(0.6)	$ (0.6)
Stock-based compensation	3.0	2.8
Loss on the sale of a businesses	0.0	2.9
Gain on the sale or disposal of property, plant and equipment	(7.0)	(0.8)
Deferred income taxes	0.1	12.6
Equity in earnings of unconsolidated entity	(0.1)	0.0
Changes in operating assets and liabilities—net of acquisitions and divestitures	23.4	(11.6)
Net cash provided by operating activities	72.9	44.7
INVESTING ACTIVITIES
Purchases of property, plant and equipment	(16.9)	(29.0)
Cost investment in unconsolidated entities	(0.3)	0.0
Proceeds from the sale of property, plant and equipment	11.4	3.6
Proceeds from the sale of businesses	0.0	41.3
Acquisition of businesses—net of cash acquired	0.0	(1.6)
Other investing activities	(0.2)	0.0
Net cash (used in) provided by investing activities	(6.0)	14.3
FINANCING ACTIVITIES
Payments of long-term debt	(33.9)	(43.9)
Payments of finance lease obligations	(0.8)	(3.1)
Borrowings on revolving credit facilities	4.4	204.8
Payments on revolving credit facilities	(5.7)	(76.7)
Equity awards redeemed to pay employees’ tax obligations	(1.1)	(1.0)
Payment of cash dividends	(1.4)	(9.5)
Other financing activities	(2.9)	0.1
Net cash (used in) provided by financing activities	(41.4)	70.7
Effect of exchange rates on cash and cash equivalents	(0.1)	(0.6)
Net increase in cash and cash equivalents	25.4	129.1
Cash and cash equivalents at beginning of period	55.2	78.7	78.7
Cash and cash equivalents at end of period	$ 80.6	$ 207.8	$ 55.2