Share Based Compensation (Summary Of Non-Vested Share Award Activity) (Details) - $ / shares shares in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Non Vested Share Awards, Equity Classified [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share awards and cash-settled awards as of December 31, 2019	6,433,000
Non-vested Granted, Shares	1,118,000
Non-vested Vested, Shares	(2,473,000)
Non-vested Forfeited, Shares	(2,096,000)
Share awards and cash-settled awards as of December 31, 2020	2,982,000	6,433,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested as of December 31, 2018, Weighted-Average Grant-Date Fair Value	$ 19.89
Non-vested Granted, Weighted-Average Grant-Date Fair Value	3,070,000.00	$ 11.50	$ 24.62
Non-vested Vested, Weighted-Average Grant-Date Fair Value	16,550,000
Non-vested Forfeited, Weighted-Average Grant-Date Fair Value	8,150,000
Non-vested as of December 31, 2019, Weighted-Average Grant-Date Fair Value	$ 16,400,000	$ 19.89
Non-Vested Share Awards, Liability Classified [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share awards and cash-settled awards as of December 31, 2019	697,000
Non-vested Granted, Shares	66,000
Non-vested Vested, Shares	(342,000)
Non-vested Forfeited, Shares	(110,000)
Share awards and cash-settled awards as of December 31, 2020	311,000	697,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested as of December 31, 2018, Weighted-Average Grant-Date Fair Value	$ 46.28
Non-vested Granted, Weighted-Average Grant-Date Fair Value	750,000	$ 0	$ 21.35
Non-vested Vested, Weighted-Average Grant-Date Fair Value	29,590,000
Non-vested Forfeited, Weighted-Average Grant-Date Fair Value	28,010,000.00
Non-vested as of December 31, 2019, Weighted-Average Grant-Date Fair Value	$ 22,740,000	$ 46.28

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

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.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

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).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
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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).

+ References

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-Topic 718
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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.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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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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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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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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