Net Income (Loss) Per Common Share - Calculation of Diluted Net Income (Loss) Per Common Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net income (loss)	$ 4,816	$ (3,118)
Denominator:
Weighted-average common shares, basic	164,247	156,637
Dilutive effect of common stock equivalents	4,150
Weighted-average common shares, diluted	168,397	156,637