SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property, plant and equipment (Details) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Property, plant and equipment
Property, plant and equipment, at cost	$ 592.5	$ 556.4
Less: Accumulated depreciation	(164.3)	(114.7)
Property, Plant and Equipment, Net, Total	$ 428.2	441.7
Number of operating segment \| segment	1
Machinery and equipment
Property, plant and equipment
Property, plant and equipment, at cost	$ 280.7	254.8
Machinery and equipment \| Minimum
Property, plant and equipment
Property, plant and equipment, useful life	10 years
Machinery and equipment \| Maximum
Property, plant and equipment
Property, plant and equipment, useful life	12 years
Building
Property, plant and equipment
Property, plant and equipment, at cost	$ 243.2	234.0
Building \| Minimum
Property, plant and equipment
Property, plant and equipment, useful life	30 years
Building \| Maximum
Property, plant and equipment
Property, plant and equipment, useful life	40 years
Land
Property, plant and equipment
Property, plant and equipment, at cost	$ 46.7	51.7
Construction in progress
Property, plant and equipment
Property, plant and equipment, at cost	$ 21.9	$ 15.9

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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