Schedule of Computation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Earnings Per Share Disclosure [Line Items]
Net income (loss)	$ (8.2)	$ (1.0)	$ (8.0)	$ 7.5
Weighted average number of common shares outstanding - basic	114.6	119.5	116.0	122.5
Stock options and restricted stock units				1.9
Weighted average number of common shares outstanding - diluted	114.6	119.5	116.0	124.4
Basic net income (loss) per share	$ (0.07)	$ (0.01)	$ (0.07)	$ 0.06
Diluted net income (loss) per share	$ (0.07)	$ (0.01)	$ (0.07)	$ 0.06
Anti-dilutive common stock equivalents	3.7	2.6	2.5	0.5