Computation of Net Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended									12 Months Ended
	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014		Dec. 27, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 28, 2012	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012
Earnings Per Share [Abstract]
Net earnings	$ 105,900	$ 107,100	$ 92,700	[1]	$ 98,000	$ 117,300	$ 112,800	$ 112,800	$ 95,300	$ 403,703	$ 438,248	$ 427,049
Weighted average shares outstanding - basic										103,964	108,352	111,376
Dilutive effect of potential common shares										1,307	1,701	2,097
Weighted average shares outstanding - diluted										105,271	110,053	113,473
Net earnings per share - basic	$ 1.04	$ 1.03	$ 0.89	[1]	$ 0.92	$ 1.09	$ 1.04	$ 1.04	$ 0.87	$ 3.88	$ 4.04	$ 3.83
Net earnings per share - diluted	$ 1.02	$ 1.02	$ 0.88	[1]	$ 0.91	$ 1.08	$ 1.03	$ 1.02	$ 0.86	$ 3.83	$ 3.98	$ 3.76
Anti-dilutive employee shared based awards, excluded										632	707	249

[1] In the second fiscal quarter of 2014, net earnings include a $25.1 million litigation charge related to a settlement agreement with the University of Pittsburgh.