Basic and Diluted Net Income (Loss) Per Share (Tables)

9 Months Ended

Sep. 30, 2018

Earnings Per Share [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2018	2017	2018	2017
Stock options	5,059	3,527	5,059	3,527
Restricted stock units	211	639	211	639
Performance-based restricted stock units (B)	335	999	335	999
Warrants	6,067	—	6,067
Total equity award shares excluded	11,672	5,165	11,672	5,165

(B) Performance-based restricted stock units are presented based on attainment of 100% of the performance goals being met.

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

A reconciliation of the numerator and the denominator used to calculate basic and diluted net loss per share is as follows (in thousands, except per share amounts):

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2018			2017			2018			2017
Numerator
Net loss	$	(1,873	)	$	(15,411	)	$	(12,952	)	$	(32,973	)
Denominator — Basic
Weighted average shares used to calculate net loss per share, basic	39,616			39,087			39,496			38,922
Denominator — Diluted
Weighted average shares used to calculate net loss per share, basic	39,616			39,087			39,496			38,922
Effect of dilutive restricted stock units (A)	—			—			—			—
Effect of dilutive stock options (A)	—			—			—			—
Weighted average shares used to calculate net loss per share, diluted	39,616			39,087			39,496			38,922
Net loss per share
Basic	$	(0.05	)	$	(0.39	)	$	(0.33	)	$	(0.85	)
Diluted	$	(0.05	)	$	(0.39	)	$	(0.33	)	$	(0.85	)