Unaudited Selected Quarterly Financial Data - Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Sep. 27, 2015	Sep. 28, 2014	Sep. 29, 2013
Quarterly Financial Information Disclosure [Abstract]
Net Sales	$ 328.8	$ 317.1	$ 296.2	$ 303.5	$ 303.3	$ 292.3	$ 287.0	$ 255.7	$ 1,245.6	$ 1,138.3	$ 975.9
Gross profit	174.8	172.1	169.3	168.1	171.0	153.6	148.6	138.3	684.3	611.5	557.2
Net income (loss)	$ 25.3	$ 14.7	$ 24.9	$ 19.7	$ 32.8	$ (4.3)	$ (6.8)	$ 1.4	$ 84.6	$ 23.1	$ 43.7
Basic earnings (loss) per share	$ 0.27	$ 0.16	$ 0.26	$ 0.21	$ 0.35	$ (0.05)	$ (0.07)	$ 0.02	$ 0.90	$ 0.25	$ 0.49
Diluted earnings (loss) per share	$ 0.26	$ 0.15	$ 0.26	$ 0.21	$ 0.34	$ (0.05)	$ (0.07)	$ 0.02	$ 0.88	$ 0.24	$ 0.48