Net Income (Loss) Per Share - Numerators and Denominators of Basic and Diluted Net Income (Loss) Per Share Computations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Sep. 28, 2012	Sep. 30, 2011
Earnings Per Share [Line Items]
Net income (loss) (numerator)	$ (8,230)	$ 3,546	$ (15,741)	$ 4,452
Shares calculation (denominator):
Weighted average shares outstanding - basic	116,517	115,791	116,946	114,855
Effect of Dilutive Securities:
Potential common stock relating to stock options, restricted stock units and ESPP		417		1,150
Weighted averages shares outstanding - diluted	116,517	116,208	116,946	116,005
Net income (loss) per share - basic	$ (0.07)	$ 0.03	$ (0.13)	$ 0.04
Net income (loss) per share - diluted	$ (0.07)	$ 0.03	$ (0.13)	$ 0.04