Fair Values (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands		Jul. 04, 2015	Sep. 27, 2014
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	[1]	$ 14,626	$ 15,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Financial Assets, Balance Sheet Location [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		45,138	20,975
Quoted Prices in Active Markets for Identical Assets (Level 1) | Financial Assets, Balance Sheet Location [Member] | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		45,138	20,975
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market fund deposits | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		13,187	5,975
Quoted Prices in Active Markets for Identical Assets (Level 1) | Certificates of Deposit [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	[3]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate notes and obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[4]	17,325	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | US And International Government [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	0	0
Fair Value, Inputs, Level 2 [Member] | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	[1]	0	0
Fair Value, Inputs, Level 2 [Member] | Financial Assets, Balance Sheet Location [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		216,734	240,908
Fair Value, Inputs, Level 2 [Member] | Financial Assets, Balance Sheet Location [Member] | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		216,485	238,712
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Forward [Member] | Other Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value		249	1,246
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Forward [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value		348	303
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts	[2]	431	366
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts	[2]	(249)	(2,196)
Fair Value, Inputs, Level 2 [Member] | Cash Flow Hedging [Member] | Other Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value		0	950
Fair Value, Inputs, Level 2 [Member] | Cash Flow Hedging [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value		83	63
Fair Value, Inputs, Level 2 [Member] | Money market fund deposits | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0	0
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0	12,084
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	[3]	0	1,400
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	8,995	23,983
Fair Value, Inputs, Level 2 [Member] | Corporate notes and obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	48,317	52,987
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[4]	0	0
Fair Value, Inputs, Level 2 [Member] | US And International Government [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	158,991	150,088
Total Fair Value | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	[1]	14,626	15,000
Total Fair Value | Financial Assets, Balance Sheet Location [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		261,872	261,883
Total Fair Value | Financial Assets, Balance Sheet Location [Member] | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		261,623	259,687
Total Fair Value | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts	[2]	431	366
Total Fair Value | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts	[2]	(249)	(2,196)
Total Fair Value | Money market fund deposits | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		13,187	5,975
Total Fair Value | Certificates of Deposit [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0	12,084
Total Fair Value | Commercial Paper [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	[3]	0	1,400
Total Fair Value | Commercial Paper [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	8,995	23,983
Total Fair Value | Corporate notes and obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	48,317	52,987
Total Fair Value | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[4]	17,325	0
Total Fair Value | US And International Government [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	$ 158,991	$ 150,088

[1] 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 markets and listed securities for which no sale was reported on that date are stated as the last quoted bid price.

[2] 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. At September 27, 2014, prepaid expenses and other assets include $303 non-designated forward contracts and $63 foreign currency contracts designated for cash flow hedges, respectively; other current liabilities include $1,246 non-designated forward contracts and $950 cash flow contracts, respectively. At July 4, 2015, prepaid expenses and other assets include $348 non-designated forward contracts and $83 cash flow contracts, respectively; other current liabilities include $249 non-designated forward contracts and $0 cash flow contracts, respectively. See Note 5, "Derivative Instruments and Hedging Activities".

[3] 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.

[4] Valuations are based upon quoted market prices.