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		6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016
Numerator:
Net loss	$ (31,500)	$ (20,679)	$ (55,527)	$ (45,859)
Denominator:
Basic and diluted	80,590	77,342	80,203	77,168
Net loss per share:
Basic and diluted	$ (0.39)	$ (0.27)	$ (0.69)	$ (0.59)