Stock-Based And Long-Term Compensation (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Summarization of stock option activity
Number of options outstanding, beginning	4,591,141
Number of options granted	2,121,417
Number of options exercised	(40,723)
Number of options forfeited	(289,820)
Number of options expired	(371,181)
Number of options outstanding, ending	6,010,834	4,591,141
Number of options exercisable	3,671,241
Number of options expected to vest	2,339,593
Weighted average option price outstanding, beginning	$ 23.60
Weighted average option price granted	9.76
Weighted average option price excercised	12.86
Weighted average option price forfeited	9.76
Weighted average option price expired	27.21
Weighted average option price outstanding, ending	19.23	$ 23.60
Weighted average option price exercisable	23.86
Weighted average option price expected to vest	$ 11.97
Weighted average remaining contractual term, outstanding	6 years	5 years 3 months 18 days
Weighted average remaining contractual term, exercisable	4 years 2 months 12 days
Weighted average remaining contractual term, expected to vest	8 years 9 months 18 days
Aggregate intrinsic value, outstanding	$ 14,145	$ 256
Aggregate intrinsic value, exercisable	1,104
Aggregate intrinsic value, expected to vest	$ 13,041