Net Income (Loss) Per Share - Computation of Basic and Diluted Net Income Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Net income (loss)	$ 900	$ (975)	$ 1,176	$ 178
Basic weighted average shares outstanding	48,933	45,175	48,007	44,944
Effect of potentially dilutive securities	4,240		4,592	3,282
Diluted weighted average shares outstanding	53,173	45,175	52,599	48,226
Basic net income (loss) per share	$ 0.02	$ (0.02)	$ 0.02	$ 0.00
Diluted net income (loss) per share	$ 0.02	$ (0.02)	$ 0.02	$ 0.00