Common Stock And Stock Options (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares, Outstanding	1,438	1,385	1,324
Number of Shares, Options forfeited, cancelled or expired	(8)	(30)	(70)
Number of Shares, Awards granted	98	303	192
Number of Shares, Awards exercised	(600)	(220)	(61)
Number of Shares, Outstanding	928	1,438	1,385
Weighted-average Exercise Price, Outstanding	$ 6.00	$ 6.54	$ 6.36
Weighted-average Exercise Price, Awards forfeited, cancelled or expired	7.20	12.42	5.75
Weighted-average Exercise Price, Awards granted		7.28	7.11
Weighted-average Exercise Price, Awards exercised	5.65	10.67	5.22
Weighted-average Exercise Price, Outstanding	$ 5.59	$ 6.00	$ 6.54
Aggregate Intrinsic Value, Outstanding	$ 19,299
Number of Shares, Exercisable	576	970
Weighted-average Exercise Price, Exercisable	$ 5.81	$ 5.42
Aggregate Intrinsic Value, Exercisable	$ 11,855	$ 13,958
Number of Shares, Available for future grant	249
Stock Options [Member]
Number of Shares, Outstanding	1,438	1,385	1,324
Number of Shares, Options forfeited, cancelled or expired	(8)	(30)	(70)
Number of Shares, Awards granted		303	192
Number of Shares, Awards exercised	(600)	(220)	(61)
Number of Shares, Outstanding	830	1,438	1,385
Restricted Stock Units (RSUs) [Member]
Number of Shares, Outstanding
Number of Shares, Awards granted	98
Number of Shares, Outstanding	98

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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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Number of share options (or share units) exercised during the current period.

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