Net Income (Loss) Per Share - Numerators and Denominators of Basic and Diluted Net Income (Loss) Per Share Computations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018
Numerator:
Net income (loss)	$ 11,657	$ (7,758)	$ (11,494)	$ (24,365)
Denominator:
Weighted Average Number of Shares Outstanding, Basic	89,964	86,321	89,030	85,188
Effect of dilutive securities from stock options, restricted stock units and ESPP	1,855	0	0	0
Effect of dilutive securities from convertible debt	3,468
Effect of dilutive securities from warrant	2,309
Diluted shares	97,596	86,321	89,030	85,188
Net income (loss) per share:
Earnings Per Share, Basic	$ 0.13	$ (0.09)	$ (0.13)	$ (0.29)
Earnings Per Share, Diluted	$ 0.12	$ (0.09)	$ (0.13)	$ (0.29)