Fair Value Measurements - Changes in Fair Value of Recurring Fair Value Measurements Using Significant Unobservable Inputs (Level 3), Consisting of Contingent Consideration Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014	Mar. 30, 2013
Fair Value Disclosures [Abstract]
Balance at beginning of period	$ 3,647	$ 93,000	$ 3,780	$ 86,368
Fair value adjustments		799		10,839
Payments	(254)	(90,172)	(387)	(93,580)
Balance at end of period	$ 3,393	$ 3,627	$ 3,393	$ 3,627