Stock Option And Stock Award Plans (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	1,164,120	1,046,800	1,076,700	1,121,500
Options may be granted to purchase specified number of common shares under stock option plan, maximum term	10 years
The total intrinsic value of stock options exercised	$ 100,000	$ 1,300,000	$ 500,000
The grant-date fair value of stock option-based awards vested	700,000	1,700,000	2,100,000
Stock options exercisable	800,050	769,825
Total stock options available for grant	2,198,235
Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Option vesting period	3 years
Stock Option-Based Awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost	1,300,000
Weighted average period for the cost expected to be recognized	1 year 4 months 26 days
Non-Vested Restricted Stock And Other Stock-Based Awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized compensation cost	$ 2,300,000
Weighted average period for the cost expected to be recognized	1 year 4 months 26 days
Granted Prior To 2012 | Employee Options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Option vesting period				2 years
Granted In 2012 And Thereafter | Employee Options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Option vesting period	4 years
Minimum
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award, Options, Outstanding, Exercise Price	$ 14.06	$ 14.06	$ 14.06	14.06