Stockholders' Equity - Schedule of Amounts Reclassified Out of Other Comprehensive Earnings (Detail) (USD $) In Thousands, 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
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Revenues	$ 812,100	$ 747,700	$ 778,500	[1]	$ 711,500	$ 769,900	$ 726,200	$ 768,400	$ 678,400	$ 3,049,800	$ 2,942,897	$ 2,807,015
Earnings before taxes										574,510	612,083	595,924
Reclassification Out of Other Comprehensive Earnings
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Earnings before taxes										(1,035)	(487)	(2,243)
Reclassification Out of Other Comprehensive Earnings | Net Unrealized Gains (Losses) Defined Benefit Pension and Post-Retirement Benefit Plans
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Cost of Revenues & Operating Expenses										(2,316)	(2,950)	(2,822)
Reclassification Out of Other Comprehensive Earnings | Net Unrealized Gains (Losses) Cash Flow Hedging Instruments
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Revenues										$ 1,281	$ 2,463	$ 579

[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.