Stockholders' Equity (Schedule Of Valuation Assumptions Used For Stock Options And ESPP Plans) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Dividend yield	0.00%	0.00%	0.00%
Stock Option [Member]
Risk-free interest rate	1.52%	1.61%	1.02%
Volatility factor of the market price of common stock	52.08%	57.96%	64.12%
Weighted-average expected life (years)	5 years 3 months 18 days	5 years	5 years 1 month 6 days
PSUs [Member]
Risk-free interest rate			1.22%
Volatility factor of the market price of common stock			63.20%
Weighted-average expected life (years)			5 years 15 days
ESPP [Member]
Risk-free interest rate	0.07%	0.04%	0.06%
Volatility factor of the market price of common stock	53.73%	42.50%	37.36%
Weighted-average expected life (years)	3 months	3 months	3 months