Acquisitions (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Oct. 31, 2014	Sep. 25, 2015	Sep. 25, 2015	Sep. 26, 2014
Business Acquisition [Line Items]
Acquisition-related transaction costs			$ 400	$ 5,900
Doremi Labs [Member]
Business Acquisition [Line Items]
Gross purchase price	$ 99,142
Cash consideration		$ (98,402)	(98,402)
Cash acquired	8,400
Cash payment	98,402
Business Combination, Contingent Consideration, Liability	$ 20,000	740	740
Business Combination, Contingent Consideration Arrangements, Earnout Period	4 years
Business Combination, Contingent Consideration, Liability, Current	$ 700	100	$ 100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchase Accounting Adjustment, Intangible Assets		4,600
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchase Accounting Adjustment, Receivables		4,200
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchase Accounting Adjustment, Goodwil		500
Goodwill, Purchase Accounting Adjustments		(3,300)
Decrease to compensation expense		(1,650)
Increase to accrued liabilities		$ 1,650