Income Taxes (Narrative) (Details) (USD $)	3 Months Ended			6 Months Ended
	Apr. 04, 2015	Jan. 03, 2015	Mar. 29, 2014	Apr. 04, 2015	Mar. 29, 2014	Sep. 30, 2014
Income Tax Disclosure [Line Items]
Effective income tax rate	(1293.00%)		10.00%	(3.00%)	18.00%
Income before income taxes	$ 387,000		$ 48,521,000	$ 34,794,000	$ 101,638,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	4,000,000			8,000,000
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	3,100,000
Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount		2,100,000
Finite-lived Intangible Assets Acquired					32,100,000
Deferred Tax Liabilities, Intangible Assets			8,900,000		8,900,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount					8,900,000
Unrecognized tax benefits	11,100,000			11,100,000		15,000,000
Income tax provision upon recognition of unrecognized tax benefit	9,700,000			9,700,000
Unrecognized tax benefits that would impact valuation allowance	3,100,000			3,100,000
Potentail reduction in unrecognized tax benefits and accrued interest over next 12 months	(4,000,000)			(4,000,000)
Adjustments to additional paid in capital, income tax benefit from share-based compensation			$ 1,300,000		$ 8,100,000