Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2016

Accounting Policies [Abstract]

Computation of Basic and Diluted Net Loss per Share

The following table sets forth the reconciliation of the numerator and denominator used in the computation of basic and diluted net loss per share for the three and six months ended June 30, 2016 and 2015 (in thousands, except per share amounts):

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2016			2015			2016			2015
Numerator for Basic and Diluted:
Net loss used for basic calculation	$	(18,166	)	$	(15,972	)	$	(35,029	)	$	(25,432	)
Effect of revaluation of warrant liability		-			-			-			(3,589	)
Adjusted net loss used for diluted calculation	$	(18,166	)	$	(15,972	)	$	(35,029	)	$	(29,021	)
Denominator:
Basic weighted average number of shares outstanding		101,563			95,728			100,517			94,576
Effect of dilutive potential shares		-			-			-			1,106
Diluted weighted average number of shares outstanding		101,563			95,728			100,517			95,682
Net loss per share:
Basic	$	(0.18	)	$	(0.17	)	$	(0.35	)	$	(0.27	)
Diluted	$	(0.18	)	$	(0.17	)	$	(0.35	)	$	(0.30	)

Anti-Dilutive Effect of Common Shares

The table below presents shares underlying stock options, restricted stock units and/or warrants that were excluded from the calculation of the weighted average number of shares outstanding used for the calculation of diluted net loss per share. These are excluded from the calculation due to their anti-dilutive effect for the three and six months ended June 30, 2016 and 2015 (shares in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2016		2015		2016		2015
Weighted average number of anti-dilutive potential shares:
Stock options		15,891		14,015		15,331		13,102
Restricted stock units		640		-		428		-
Warrants		-		2,985		-		-
Total		16,531		17,000		15,759		13,102