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Restructuring (Details) $ in Thousands	3 Months Ended	12 Months Ended
Restructuring (Details) $ in Thousands	Sep. 26, 2014 USD ($)	Sep. 25, 2015 USD ($)	Sep. 26, 2014 USD ($) employee	Sep. 27, 2013 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Share based compensation expense		$ (67,069)	$ (65,680)	$ (64,328)
Related party rent expense		3,136	2,125	2,526
Restructuring Reserve [Roll Forward]
Restructuring charges		(80)	2,403	$ 5,874
Restructuring Charges [Member]
Restructuring Reserve [Roll Forward]
Restructuring charges			$ 3,300
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated \| employee			50
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance		146
Restructuring charges		(39)	$ 3,301
Cash payments		(10)	(3,164)
Non-cash charges		(97)	9
Restructuring reserve, ending balance	$ 146	0	146
2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated \| employee				36
Share based compensation expense				$ (1,900)
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance		0	1,837
Restructuring charges			(898)	5,874
Cash payments			(794)	(2,205)
Non-cash charges	(700)		(145)	(1,832)
Restructuring reserve, ending balance	0		0	1,837
2013 Restructuring Program [Member] \| Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance		0	1,043
Restructuring charges			(898)	1,151
Cash payments			0	(108)
Non-cash charges			(145)	0
Restructuring reserve, ending balance	0		0	1,043
2013 Restructuring Program [Member] \| Severance And Other Associated Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance		$ 0	794
Restructuring charges			0	4,723
Cash payments			(794)	(2,097)
Non-cash charges			0	(1,832)
Restructuring reserve, ending balance	$ 0		$ 0	794
2013 Restructuring Program [Member] \| Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Recorded severance and other associated costs				2,800
2013 Restructuring Program [Member] \| Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Related party rent expense				$ 1,200