Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 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 three and nine months ended September 30, 2016 and 2015 (in thousands, except per share amounts):

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2016			2015			2016			2015
Numerator for Basic and Diluted:
Net loss used for basic calculation	$	(14,376	)	$	(15,680	)	$	(49,405	)	$	(41,112	)
Effect of revaluation of warrant liability		-			(1,109	)		-			(4,698	)
Adjusted net loss used for diluted calculation	$	(14,376	)	$	(16,789	)	$	(49,405	)	$	(45,810	)
Denominator:
Basic weighted average number of shares outstanding		102,769			96,864			101,273			95,347
Effect of dilutive potential shares		-			741			-			993
Diluted weighted average number of shares outstanding		102,769			97,605			101,273			96,340
Net loss per share:
Basic	$	(0.14	)	$	(0.16	)	$	(0.49	)	$	(0.43	)
Diluted	$	(0.14	)	$	(0.17	)	$	(0.49	)	$	(0.48	)

Anti-Dilutive Effect of Common Shares

The table below presents shares underlying stock options and restricted stock units 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 nine months ended September 30, 2016 and 2015 (shares in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
Weighted average number of anti-dilutive potential shares:
Stock options		15,851		14,264		15,506		13,494
Restricted stock units		699		-		519		-
Total		16,550		14,264		16,025		13,494