Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jan. 02, 2016	Jan. 03, 2015	Sep. 30, 2015
Income Tax Disclosure [Line Items]
Effective income tax rate	(22.00%)	12.00%
Income before income taxes	$ (19,545)	$ 34,407
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	3,000	4,000
Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount	2,600	$ 2,100
Unrecognized tax benefits	14,400		$ 14,100
Income tax provision upon recognition of unrecognized tax benefit	12,800
Unrecognized tax benefits that would impact valuation allowance	4,600
Potentail reduction in unrecognized tax benefits and accrued interest over next 12 months	$ (4,000)