Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Sep. 28, 2013 item sqft	Sep. 29, 2012	Sep. 24, 2011	Jun. 30, 2012
Legal Proceedings
Total rent expense	$ 23,100,000	$ 25,100,000	$ 18,100,000
Sublease income	1,100,000	300,000	300,000
Initial term of capital lease	15 years
Number of additional optional renewals of capital lease	6
Capital leases optional renewal term	5 years
Area of property to be leased in Burlington, Massachusetts	425,000
Area of space completed	150,000
Area of space under construction	275,000
Properties under construction				4,100,000
Capital Leases
2014	3,518,000
2015	3,838,000
2016	3,837,000
2017	3,837,000
2018	3,837,000
Thereafter	31,980,000
Total	50,847,000
Less: amount representing interest	(17,075,000)
Present value of future minimum lease payments	33,772,000
Operating Leases
2014	16,602,000
2015	15,534,000
2016	11,797,000
2017	8,631,000
2018	5,280,000
Thereafter	20,140,000
Total	77,984,000
Subleases
2014	(1,021,000)
2015	(1,012,000)
2016	(848,000)
2017	(690,000)
2018	(634,000)
Thereafter	(2,156,000)
Total minimum income	(6,361,000)
Financing Obligations
2014	2,029,000
2015	8,661,000
2016	9,580,000
2017	9,580,000
2018	9,665,000
Thereafter	113,722,000
Total	$ 153,237,000
Maximum
Legal Proceedings
Operating leases term	20 years
Minimum
Legal Proceedings
Operating leases term	1 year