Share-based Compensation (Narrative) (Details)	1 Months Ended	3 Months Ended
Mar. 31, 2018 shares	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of annual incentive compensation receivable in shares	100.00%	100.00%
2018 PSUs [Member] \| PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award grant (in shares)	1,303,776
Award performance period		2 years
2018 PSUs [Member] \| PSUs [Member] \| April 1, 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights		50.00%
2018 PSUs [Member] \| PSUs [Member] \| October 1, 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights		50.00%
2018 PSUs [Member] \| PSUs [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award performance range		50.00%
Award expected performance	50.00%	50.00%
2018 PSUs [Member] \| PSUs [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award performance range		125.00%
Award expected performance	150.00%	150.00%

Share-based Compensation Arrangement by Share-based Payment Award, Award Expected Performance

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period

+ References

No definition available.

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Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Range

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- Definition

Shareholder Inventive Program, Percent of Annual Incentive Compensation

+ References

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

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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- Definition

Percentage of vesting of share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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