Fair Values (Details) - USD ($) $ in Thousands		Sep. 29, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Short-term Debt		$ 5,072	$ 5,078
Long-term debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Long-term Debt		420,711	589,001
Recurring | Aggregate Fair Value | Assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		79,796	150,438
Recurring | Aggregate Fair Value | Other current liabilities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		77,917	148,963
Recurring | Aggregate Fair Value | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid and other assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund Deferred comp and supplemental plan, fair value	[1]	522	285
Mutual funds - Deferred comp and supplemental plan	[1]	21,862	17,585
Recurring | Aggregate Fair Value | Money market fund deposits | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits		56,285	61,811
Recurring | Aggregate Fair Value | U.S. Treasury and agency obligations | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits	[2]	0	14,986
Recurring | Aggregate Fair Value | U.S. Treasury and agency obligations | Short-term investments:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	[2]	120	21,087
Recurring | Aggregate Fair Value | Commercial paper | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits	[2]	0	21,991
Recurring | Aggregate Fair Value | Corporate notes and obligations | Short-term investments:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	[2]	0	11,423
Recurring | Aggregate Fair Value | Foreign exchange contracts | Prepaid and other assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
U.S. Fair Value	[3]	1,007	1,270
Recurring | Aggregate Fair Value | Foreign exchange contracts | Other current liabilities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
U.S. Fair Value	[3]	(1,879)	(1,475)
Recurring | (Level 1) | Assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		78,669	79,681
Recurring | (Level 1) | Other current liabilities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		78,669	79,681
Recurring | (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid and other assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund Deferred comp and supplemental plan, fair value	[1]	522	285
Mutual funds - Deferred comp and supplemental plan	[1]	21,862	17,585
Recurring | (Level 1) | Money market fund deposits | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits		56,285	61,811
Recurring | (Level 1) | U.S. Treasury and agency obligations | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits	[2]	0	0
Recurring | (Level 1) | U.S. Treasury and agency obligations | Short-term investments:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	[2]	0	0
Recurring | (Level 1) | Commercial paper | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits	[2]	0	0
Recurring | (Level 1) | Corporate notes and obligations | Short-term investments:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	[2]	0	0
Recurring | (Level 1) | Foreign exchange contracts | Prepaid and other assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
U.S. Fair Value	[3]	0	0
Recurring | (Level 1) | Foreign exchange contracts | Other current liabilities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
U.S. Fair Value	[3]	0	0
Recurring | (Level 2) | Assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		1,127	70,757
Recurring | (Level 2) | Other current liabilities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		(752)	69,282
Recurring | (Level 2) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid and other assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund Deferred comp and supplemental plan, fair value	[1]	0	0
Mutual funds - Deferred comp and supplemental plan	[1]	0	0
Recurring | (Level 2) | Money market fund deposits | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits		0	0
Recurring | (Level 2) | U.S. Treasury and agency obligations | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits	[2]	0	14,986
Recurring | (Level 2) | U.S. Treasury and agency obligations | Short-term investments:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	[2]	120	21,087
Recurring | (Level 2) | Commercial paper | Cash equivalents:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund deposits	[2]	0	21,991
Recurring | (Level 2) | Corporate notes and obligations | Short-term investments:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	[2]	0	11,423
Recurring | (Level 2) | Foreign exchange contracts | Prepaid and other assets:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
U.S. Fair Value	[3]	1,007	1,270
Recurring | (Level 2) | Foreign exchange contracts | Other current liabilities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
U.S. Fair Value	[3]	$ (1,879)	$ (1,475)

[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] 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.

[3] 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. See Note 6, "Derivative Instruments and Hedging Activities."