Fair Value Measurements - Changes in Fair Value of Recurring Fair Value Measurements, Consisting of Contingent Consideration Liabilities, Using Significant Unobservable Inputs Level 3 (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 29, 2012	Dec. 24, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 86,368	$ 103,790
Accretion charges	10,040	5,122
Payments made	(3,408)	(4,105)
Balance at end of period	$ 93,000	$ 104,807