Fair Values (Details) (Fair Value, Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Jun. 29, 2013		Sep. 29, 2012
Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	$ (640)		$ (21)
Total Fair Value | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	13,480		6,400
Total Fair Value | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	19,447		10,340
Total Fair Value | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	19,590		31,253
Total Fair Value | U.S. and international government obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure			110,967
Total Fair Value | US Treasury and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	95,040
Total Fair Value | Corporate notes and obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	15,338		43,406
Total Fair Value | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	9,994		2,000
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	0	[1],[2]	0	[1],[3]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	13,480	[4],[5]	6,400	[4],[6]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid expenses and other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	1,876		2,891
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	11,604		3,509
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	19,447	[7]	10,340	[7]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[7],[8]	0	[8],[9]
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. and international government obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure			0	[10],[8]
Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	0	[10],[8]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate notes and obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	0	[10],[8]	0	[11],[8]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	0	[10],[8]	0	[10],[8]
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	(640)	[1],[2]	(21)	[1],[3]
Significant Other Observable Inputs (Level 2) | Prepaid expenses and other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	170		626
Significant Other Observable Inputs (Level 2) | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	(810)		(645)
Significant Other Observable Inputs (Level 2) | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	0	[4],[5]	0	[4],[6]
Significant Other Observable Inputs (Level 2) | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[7]	0	[7]
Significant Other Observable Inputs (Level 2) | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	19,590	[7],[8]	31,253	[8],[9]
Significant Other Observable Inputs (Level 2) | Certificates of deposit | Cash and Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			29,234
Significant Other Observable Inputs (Level 2) | Certificates of deposit | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			2,019
Significant Other Observable Inputs (Level 2) | U.S. and international government obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure			110,967	[10],[8]
Significant Other Observable Inputs (Level 2) | US Treasury and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	95,040	[10],[8]
Significant Other Observable Inputs (Level 2) | Corporate notes and obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	15,338	[10],[8]	43,406	[11],[8]
Significant Other Observable Inputs (Level 2) | Corporate notes and obligations | Cash and Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure			1,223
Significant Other Observable Inputs (Level 2) | Corporate notes and obligations | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure			42,183
Significant Other Observable Inputs (Level 2) | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 9,994	[10],[8]	$ 2,000	[10],[8]

[1] The principal market in which we execute our foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. Our foreign currency contracts’ valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment.

[2] Includes $170 recorded in prepaid expenses and other assets and $810 recorded in other current liabilities on the Condensed Consolidated Balance Sheet (see Note 5).

[3] Includes $626 recorded in prepaid expenses and other assets and $645 recorded in other current liabilities on the Condensed Consolidated Balance Sheet.

[4] The fair value of mutual funds is determined based on quoted market prices. Securities traded on a national exchange are stated at the last reported sales price on the day of valuation; other securities traded in over-the-counter market and listed securities for which no sale was reported on that date are stated as the last quoted bid price.

[5] Includes $1,876 recorded in prepaid expenses and other assets and $11,604 recorded in other assets on the Condensed Consolidated Balance Sheet.

[6] Includes $2,891 recorded in prepaid expenses and other assets and $3,509 recorded in other assets on the Condensed Consolidated Balance Sheet.

[7] Included in cash and cash equivalents on the Condensed Consolidated Balance Sheet. The carrying amounts approximate fair value due to the short-term maturities of the cash equivalents.

[8] Valuations are based upon quoted market prices in active markets involving similar assets. The market inputs used to value these instruments generally consist of market yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources include industry standard data providers, security master files from large financial institutions, and other third party sources which are input into a distribution-curve-based algorithm to determine a daily market value. This creates a “consensus price” or a weighted average price for each security.

[9] Includes $29,234 recorded in cash and cash equivalents and $2,019 recorded in short-term investments on the Condensed Consolidated Balance Sheet.

[10] Included in short-term investments on the Condensed Consolidated Balance Sheet.

[11] Includes $1,223 recorded in cash and cash equivalents and $42,183 recorded in short-term investments on the Condensed Consolidated Balance Sheet.