Employee Stock Plans - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended				12 Months Ended									12 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011	Sep. 26, 2014 Stock Options	Sep. 26, 2014 Restricted Stock Restricted Stock Units Deferred Stock Units And Performance Units	Sep. 26, 2014 Restricted Stock, Restricted Stock Units And Deferred Stock Units	Sep. 26, 2014 The 2000 Plan	Sep. 26, 2014 The 2000 Plan Maximum	Feb. 29, 2012 Third Amended 2005 Plan	Sep. 26, 2014 Third Amended 2005 Plan Before February 16, 2007	Sep. 26, 2014 Third Amended 2005 Plan Between February 16, 2007 and February 8, 2012	Sep. 26, 2014 Third Amended 2005 Plan After February 9, 2012	Sep. 26, 2014 Third Amended 2005 Plan Stock Options awarded before February 16, 2007	Sep. 26, 2014 Third Amended 2005 Plan Stock Options awarded after February 16, 2007	Sep. 26, 2014 Third Amended 2005 Plan Deferred Stock Units	Sep. 27, 2013 Third Amended 2005 Plan Performance Units	Sep. 26, 2014 Third Amended 2005 Plan Maximum Restricted Stock And Restricted Stock Unit	Sep. 26, 2014 Third Amended 2005 Plan Minimum Restricted Stock And Restricted Stock Unit	Sep. 26, 2014 Third Amended 2005 Plan Minimum Deferred Stock Units	Sep. 26, 2014 Employee Stock Purchase Plans
Employee Stock Plans [Line Items]
Number of shares authorized			6,000,000					12,000,000		24,950,000
Vesting period								The first one-third of the option shares one year from the date of grant, with the remainder vesting monthly during the following two-year period.
Award expiration period									10 years					10 years	7 years
Award vesting period																1 year		3 years	1 year	1 year
Award performance period																	3 years
Maximum payout of shares that could be issued for each performance unit granted	1.5
Shares counted against the available for grant											3	2.5	2.6
Total pre-tax intrinsic value of options exercised	$ 54.4	$ 66.3	$ 29.8
Unrecognized compensation expense related to outstanding stock awards					10.5	35.8
Weighted average period unrecognized compensation expense is expected to be recognized, years					1 year 8 months 12 days	1 year 9 months 18 days
Shares vested during the year, number	335,000	396,000	469,000				335,032
Shares vested during the year, fair value							25.4
Shares withheld for employees minimum withholding taxes at vesting, number	115,987
Shares withheld for employees minimum withholding taxes at vesting, fair value	8.8
Maximum number of shares purchased	7,000,000
Common stock employee purchase price percentage lower than fair market value	85.00%
Shares issued, number	261,230	262,455
Shares issued, value	$ 15.3	$ 14.2
Shares available for issuance	8,168,000	9,925,000	11,868,000	8,424,000																	6,100,000