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Share-Based Compensation (Schedule of Performance Award Details) (Details) - Performance Shares - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 1,384,336 | 1,503,251 |
NOEPS |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value | $ 11.7 | $ 11.7 | $ 9.2
NOEPS | 2020 award |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 392,619 |  |
NOEPS | 2019 Award |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 384,680 |  |
NOEPS | 2018 Award |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 347,479 |  |
CVI |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value | $ 2.6 | $ 2.5 | $ 2.4
CVI | 2020 award |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 90,604 |  |
CVI | 2019 Award |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 88,769 |  |
CVI | 2018 Award |  |  |
Performance Share Details [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 80,185 |  |

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- Definition Performance Share Details + References No definition available. + Details
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- Definition 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 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)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. + References 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 (d)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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