| **Employee Stock And Incentive Plan (Narrative) (Details) - USD ($) $ in Thousands** | 12 Months Ended         |
|--------------------------------------------------------------------------------------|-------------------------|
||
| 2009 Plan [Member]                                                                   |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Number of shares authorized for issuance                                             | 6,250,000               |   |
| Maximum number of shares available for issuance may be issued as restricted stock    | 3,125,000               |   |
| Maximum number of shares subject to grants to any one individual in any one year     | 500,000                 |   |
| Underlying stock option and restricted stock awards available for grant              | 3,374,238               |   |
| Performance Share Units [Member]                                                     |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Performance period specified in grant, in years                                      | 3 years                 |   |
| Unrecognized compensation costs                                                      | $ 5,350                 |   |
| Period over which unrecognized compensation cost will be recognized                  | 1 year 9 months 18 days |   |
| Aggregate intrinsic value                                                            | $ 15,160                |   |
| Performance Share Units [Member] | Minimum [Member]                                  |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Percentage of target award amount the grantee may earn                               | 0.00%                   |   |
| Performance Share Units [Member] | Maximum [Member]                                  |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Percentage of target award amount the grantee may earn                               | 200.00%                 |   |
| Amortization period of fair value of shares, in months                               | 36 months               |   |
| Vesting period, in years                                                             | 3 years                 |   |
| Restricted Stock Units [Member]                                                      |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Unrecognized compensation costs                                                      | $ 1,927                 |   |
| Vesting period, in years                                                             | 3 years                 |   |
| Period over which unrecognized compensation cost will be recognized                  | 1 year 4 months 24 days |   |
| Aggregate intrinsic value                                                            | $ 4,448                 |   |
| Stock Options [Member]                                                               |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Unrecognized compensation costs                                                      | $ 453                   |   |
| Vesting period, in years                                                             | 1 year 6 months         |   |
| Return on equity                                                                     | 1.50%                   |   |
| Number of options granted                                                            |                    | 0 |
| Stock Options [Member] | Share-based Compensation Award, Tranche One [Member]        |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Vesting percentage                                                                   | 33.00%                  |   |
| Stock Options [Member] | Minimum [Member]                                            |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Vesting period, in years                                                             | 1 year                  |   |
| Stock Options [Member] | Maximum [Member]                                            |                    |   |
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**   |                    |   |
| Vesting period, in years                                                             | 10 years                |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Unrecognized cost of unvested share-based compensation awards.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
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| X                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of public utility's requested return on equity.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
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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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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The highest quantity of shares an employee can purchase under the plan per period.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Net number of share options (or share units) granted during the period.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of vesting of share-based compensation awards.
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| X                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of target award amount the participant may earn
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| X                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Performance Period Specified In Grant
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| X                                                                                                                                                                                                                                                                                                                                                                                             |
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| - Definition
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| X                                                                                                                                                                                                                                                                                                                                                                                                                               |
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| - Definition
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Total Intrinsic Value
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| - Definition
Share Based Compensation Arrangement By Share Based Payment Award Maximum Number Of Shares Available For Issuance May Be Issued As Restricted Stock
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| X                                                                                                                       |
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| X                                                                                                                       |
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| X                                                                                                                                                               |
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