Share-Based Compensation (Summary Of Valuation Assumptions) (Details)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected annual dividend yield	0.00%		0.00%		0.00%
Plan Based [Member] | Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term	5 years	[1]	6 years	[1]	5 years	[1]
Expected volatility	97.90%	[2]	90.20%	[2]	92.00%	[2]
Risk-free interest rate	0.80%	[3]	0.80%	[3]	0.90%	[3]
Plan Based [Member] | Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term	6 years	[1]	7 years	[1]	6 years	[1]
Expected volatility	103.70%	[2]	94.80%	[2]	97.70%	[2]
Risk-free interest rate	1.80%	[3]	1.00%	[3]	2.00%	[3]
Non Plan [Member] | Warrants And Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected annual dividend yield	0.00%		0.00%		0.00%
Non Plan [Member] | Warrants And Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term	4 years	[4]	4 years	[4]	4 years	[4]
Expected volatility	91.50%	[5]	93.40%	[5]	89.40%	[5]
Risk-free interest rate	0.50%	[6]	0.70%	[6]	0.90%	[6]
Non Plan [Member] | Warrants And Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term	5 years	[4]	6 years	[4]	5 years	[4]
Expected volatility	104.00%	[5]	104.30%	[5]	100.20%	[5]
Risk-free interest rate	1.00%	[6]	1.00%	[6]	2.40%	[6]

[1] The expected term was generally determined based on historical activity for grants with similar terms and for similar groups of employees and represents the period of time that options are expected to be outstanding. For employee options, groups of employees with similar historical exercise behavior are considered separately for valuation purposes. For consultants, the expected term was determined based on the contractual life of the award.

[2] The stock volatility for each grant is measured using the weighted average of historical daily price changes of our common stock over the most recent period equal to the expected option life of the grant.

[3] The risk-free interest rate for periods equal to the expected term of the share option is based on the U.S. Treasury yield curve in effect at the measurement date.

[4] The expected term was determined based on the remaining contractual life of the award on the measurement date.

[5] The stock volatility for each grant is measured using the weighted average of historical daily price changes of our common stock over the most recent period equal to the expected life of the award.

[6] The risk-free interest rate for periods equal to the expected term of the award is based on the U.S. Treasury yield curve in effect at the measurement date.