Fair Value Measurements (Summary of Financial Assets Measured at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 30, 2016	Sep. 30, 2016	Jan. 01, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets	$ 13,172	$ 12,637	$ 12,142
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets	13,172	12,637	12,142
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets