Income Taxes (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011	Sep. 30, 2011
Income Tax Disclosure [Line Items]
Effective income tax rate	26.00%	15.00%	25.00%	16.00%
Income before income taxes	$ 30,800,000	$ 18,300,000	$ 64,600,000	$ 56,900,000
Statutory Federal income tax rate	35.00%	35.00%
Noncash charge related to Japanese legislative change and expiration of U.S. R&D tax credit	4,200,000		1,500,000
Tax benefit related to retroactive extension of R&D tax credit		1,800,000
Deferred Tax Assets, Net					121,900,000
Unrecognized tax benefit	16,400,000		16,400,000		16,200,000
Unrecognized tax benefits, net of state tax benefits	16,100,000				15,900,000
Income tax provision upon recognition of unrecognized tax benefit	15,200,000		15,200,000
Income tax interest expense			200,000
Income tax penalty	100,000
Income tax accrued interest	2,200,000		2,200,000		2,000,000
Income tax accrued penalty	100,000		100,000
Maximum amount of decrease in unrecognized tax benefits	6,000,000		6,000,000
Payment From Foreign Subsidiary [Member]
Income Tax Disclosure [Line Items]
Potential tax benefit from not receiving research and development cost sharing prepayment from foreign subsidiary	$ 7,500,000		$ 7,500,000