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Benefit Plans (Summary Of Performance Shares and Performance Units Vested Awards) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Performance Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) | 90,806 | 99,438 | 98,186
Performance Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) | 31,910 | 37,395 | 42,760
2015 Grant [Member] | Performance Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) | 90,806 |  |
Vested percentage of the target | 137.50% |  |
Cash and stock payout value | $ 5.3 |  |
Cash payout value | $ 4.9 |  |
Common stock shares from vested performance shares (in shares) | 5,078 |  |
2015 Grant [Member] | Performance Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) | 31,910 |  |
Vested percentage of the target | 137.50% |  |
Cash and stock payout value | $ 1.4 |  |
Cash payout value | $ 1.4 |  |
2014 Grant [Member] | Performance Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) |  | 99,438 |
Vested percentage of the target |  | 147.50% |
Cash and stock payout value |  | $ 5.6 |
Cash payout value |  | $ 5.1 |
Common stock shares from vested performance shares (in shares) |  | 5,185 |
2014 Grant [Member] | Performance Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) |  | 37,395 |
Vested percentage of the target |  | 147.50% |
Cash and stock payout value |  | $ 1.5 |
Cash payout value |  | $ 1.5 |
2013 Grant [Member] | Performance Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) |  |  | 98,186
Vested percentage of the target |  |  | 165.00%
Cash and stock payout value |  |  | $ 5.1
Cash payout value |  |  | $ 2.9
Common stock shares from vested performance shares (in shares) |  |  | 22,408
2013 Grant [Member] | Performance Units [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vested (in shares/awards) |  |  | 42,760
Vested percentage of the target |  |  | 165.00%
Cash and stock payout value |  |  | $ 1.7
Cash payout value |  |  | $ 1.7

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- Definition Amount of cost (reversal of cost) for employee benefits and share-based payment arrangement. Includes, but is not limited to, pension, other postretirement, postemployment and termination benefits. + References No definition available. + Details
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- Definition Aggregate cash paid by the entity during the period to settle equity instruments granted under equity-based payment arrangements. + 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 (k) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + 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)(2) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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