Basic and Diluted Net Income (Loss) Per Share - Computation of Basic and Diluted Net Income (Loss) per Share to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net income available (loss attributable) to common stockholders	$ 17,986	$ 13,080	$ (28,883)
Denominator:
Shares used in computing net income available (loss attributable) per share to common stockholders, basic	108,190	106,088	83,446
Weighted-average effect of potentially dilutive shares to purchase common stock	4,348	3,770
Shares used in computing net income available (loss attributable) per share to common stockholders, diluted	112,538	109,858	83,446
Net income available (loss attributable) per share to common stockholders:
Basic	$ 0.17	$ 0.12	$ (0.35)
Diluted	$ 0.16	$ 0.12	$ (0.35)