Income Taxes Narrative (Details) (USD $)	12 Months Ended
	Sep. 30, 2011	Oct. 01, 2010	Oct. 02, 2009
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 500,000
Income Tax Credits and Adjustments	6,200,000
Income Tax Reconciliation, Nondeductible Expense, Restructuring Charges	0	(3,468,000)	0
Income Tax Reconciliation Nondeductible Restructuring Charges Benefit		6,300,000
Income Tax Reconciliation Nondeductible Restructuring Charges Provision		2,800,000
Valuation Allowance, Amount	39,400,000
Deferred Taxes, Business Combination, Valuation Allowance, Available to Reduce Income Tax Expense	11,600,000
Tax benefit to recognize if valuation allowance is reversed	39,000,000
Deferred Taxes, Business Combination, Valuation Allowance, Available to Reduce Goodwill	400,000
Deferred Tax Assets, Tax Credit Carryforwards	180,200,000
Unrecognized Tax Benefits, Period Increase (Decrease)		1,000,000
Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance	2,152,000	2,834,000	(39,089,000)
Change in deferred tax asset valuation allowance in additioan paid in capital		3,800,000
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	60,500,000
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	1,300,000
Tax Credit Carryforward, Amount	80,100,000
Valuation Allowance Not Recognized	23,000,000
Deferred Tax Liabilities, Undistributed Foreign Earnings	147,000,000
Unrecognized Tax Benefits	32,136,000	19,900,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	19,700,000
Other Tax Carryforward, SiGe Acquisition [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	43,300,000
Foreign Country [Member]
Valuation Allowance, Amount	13,300,000
Deferred Tax Asset Change Due To Change In Legislation	(1,100,000)
State and Local Jurisdiction [Member]
Valuation Allowance, Amount	26,100,000
Deferred Tax Asset Change Due To Change In Legislation	$ (800,000)