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, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 11,353	$ 5,367	$ 7,359
Income tax benefits	2,384	1,127	2,576
Excess tax benefits on settled share-based employee payments	$ (612)	$ 990	$ 2,348
Federal statutory tax rate	21.00%	21.00%	35.00%	21.00%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period	3 years
Shares granted during the year	50,061	40,661	57,746
Shares vested during the year	(48,228)	(53,352)	(57,473)
Unvested shares at end of year	93,351	91,998	106,053	93,351
Unrecognized compensation expense at end of year (in thousands)	$ 2,054	$ 1,964	$ 1,853	$ 2,054
Total Shareholder Return Market-Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted during the year	99,214	80,724	114,390
Shares vested during the year	(106,858)	(107,342)	(107,649)
Shares earned based on market metrics	0	0	158,262
Unvested shares at end of year	178,035	187,172	218,507	178,035
Unrecognized compensation expense at end of year (in thousands)	$ 3,377	$ 3,706	$ 2,849	$ 3,377
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted during the year	49,609	40,329	57,223
Shares vested during the year	(53,454)	(53,699)	(53,862)
Shares earned based on market metrics	106,908	30,102	41,502
Unvested shares at end of year	88,990	93,579	108,581	88,990
Unrecognized compensation expense at end of year (in thousands)	$ 2,401	$ 1,260	$ 1,856	$ 2,401
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	$ 900	$ 300		$ 900
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%			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%			200.00%

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