Stock-Based Compensation (Schedule Of Non-Vested Restricted Stock Award and RSU Activity and Changes) (Details) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) $ / shares shares
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount \| $	$ 15
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 8 months 12 days
Number of Shares
Number of Shares, Non-vested, beginning balance \| shares	702,789
Number of Shares, Granted \| shares	205,517
Number of Shares, Vested \| shares	(415,593)
Number of Shares, Forfeited \| shares	(29,430)
Number of Shares, Non-vested, ending balance \| shares	463,283
Weighted Average Grant Date Fair Value
Weighted Average Fair Value, Non-vested, beginning balance (in dollars per share) \| $ / shares	$ 65.79
Weighted Average Fair Value, Granted (in dollars per share) \| $ / shares	77.59
Weighted Average Fair Value, Vested (in dollars per share) \| $ / shares	56.70
Weighted Average Fair Value, Forfeited (in dollars per share) \| $ / shares	73.28
Weighted Average Fair Value, Non-vested, ending balance (in dollars per share) \| $ / shares	$ 78.69
Axiall Corporation [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount \| $	$ 0
Number of Shares
Number of Shares, Non-vested, beginning balance \| shares	49,528
Number of Shares, Vested \| shares	(49,292)
Number of Shares, Forfeited \| shares	(236)
Number of Shares, Non-vested, ending balance \| shares	0
Weighted Average Grant Date Fair Value
Weighted Average Fair Value, Non-vested, beginning balance (in dollars per share) \| $ / shares	$ 66.46
Weighted Average Fair Value, Vested (in dollars per share) \| $ / shares	68.22
Weighted Average Fair Value, Forfeited (in dollars per share) \| $ / shares	76.77
Weighted Average Fair Value, Non-vested, ending balance (in dollars per share) \| $ / shares	$ 0

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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