Stock-Based And Long-Term Compensation (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Summarization of stock option activity
Number of options outstanding, beginning	4,484,505
Number of options granted	612,665
Number of options exercised	(506,029)
Number of options outstanding, ending	4,591,141	4,484,505
Number of options exercisable	3,488,262
Number of options expected to vest	1,102,879
Weighted average option price outstanding, beginning	$ 23.76
Weighted average option price granted	17.27
Weighted average option price excercised	17.43
Weighted average option price outstanding, ending	23.60	$ 23.76
Weighted average option price exercisable		$ 24.48
Weighted average option price expected to vest	$ 20.81
Weighted average remaining contractual term, outstanding	5 years 3 months 18 days	5 years 1 month 6 days
Weighted average remaining contractual term, exercisable	4 years 3 months 18 days
Weighted average remaining contractual term, expected to vest	8 years 6 months
Aggregate intrinsic value, outstanding	$ 256	$ 4,095
Aggregate intrinsic value, exercisable	$ 256