Summary Of Significant Accounting Policies Summary of Significant Accounting Policies (Stock-Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended	24 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 5,367	$ 7,359	$ 7,891
Income tax benefits	1,127	2,576	2,762
Excess tax benefits on settled share-based employee payments	$ 990	$ 2,348	$ 1,597
Federal statutory tax rate	21.00%	35.00%	35.00%	35.00%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period	3 years
Shares granted during the year	40,661	57,746	58,610
Shares vested during the year	(53,352)	(57,473)	(52,385)
Unvested shares at end of year	91,998	106,053	109,806	106,053
Unrecognized compensation expense at end of year (in thousands)	$ 1,964	$ 1,853	$ 1,853	$ 1,853
Total Shareholder Return Market-Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted during the year	80,724	114,390	116,435
Shares vested during the year	(107,342)	(107,649)	(111,665)
Shares earned based on market metrics	0	158,262	132,887
Unvested shares at end of year	187,172	218,507	222,228	218,507
Unrecognized compensation expense at end of year (in thousands)	$ 3,706	$ 2,849	$ 3,409	$ 2,849
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted during the year	40,329	57,223	57,521
Shares vested during the year	(53,699)	(53,862)	(55,835)
Shares earned based on market metrics	30,102	41,502	90,460
Unvested shares at end of year	93,579	108,581	110,452	108,581
Unrecognized compensation expense at end of year (in thousands)	$ 1,260	$ 1,856	$ 1,671	$ 1,856
Total Shareholder Return Market-Based Awards and Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period	3 years
Dividend Component Liability, Current	$ 300	$ 1,500		$ 1,500
Minimum [Member] \| Total Shareholder Return Market-Based Awards and Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued range, percent of the performance shares granted	0.00%
Maximum [Member] \| Total Shareholder Return Market-Based Awards and Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued range, percent of the performance shares granted	200.00%

Common stock issued range, percent of the performance shares granted.

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The number of common stock shares earned during the reporting period including market conditions.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable within one year (or the operating cycle, if longer).

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Unrecognized cost of unvested share-based compensation awards.

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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).

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