ACCOUNTING POLICIES (Details 1) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Acquisition-related costs	$ 0.0	$ 0.0	$ 1.0
Gain (loss) on disposition of property, plant and equipment	(0.8)		1.7
Gains on insurance recoveries	0.0	0.0	8.0
Short-term investments	0.0	0.0
Asset retirement obligation non-current portion	47.0	53.4
Asset retirement obligation revision of estimate	1.9	4.5
Finite-lived intangible asset impairment charge	$ 0.0	$ 0.0	$ 0.0
Average remaining life expectancy of the inactive participants in the defined benefit pension plan (in years)	18 years	18 years

Average remaining life expectancy of inactive participants in defined benefit pension plan.

No definition available.

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- Definition

The gain recorded in other operating income due to insurance recoveries for property damage and business interruption.

+ References

No definition available.

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- References

No definition available.

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- Definition

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

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- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

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- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

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- Definition

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

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