Net Income (Loss) Per Share - Net Income (Loss) Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator:
Net loss available to stockholders	$ (1,142)	$ (13,049)	$ (12,004)	$ (26,451)
Denominator:
Weighted average shares outstanding - basic	41,225	37,036	39,165	36,967
Potential common shares - options (treasury stock method)
Weighted average shares outstanding - diluted	41,225	37,036	39,165	36,967
Shares excluded (anti-dilutive)	2		13	3
Shares excluded due to an exercise price greater than weighted average stock price for the period	1,596	2,271	1,536	2,261
Net loss per share:
Basic	$ (0.03)	$ (0.35)	$ (0.31)	$ (0.72)
Diluted	$ (0.03)	$ (0.35)	$ (0.31)	$ (0.72)