Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Statement Of Stockholders Equity [Abstract]
Deferred tax benefit (expense), Pension liability	$ (24,380)	$ 13,303	$ (438)
Deferred tax expense (benefit) , Other comprehensive income (loss), Gain\(Loss) on derivatives	90	(274)	766
Deferred tax expense (benefit), Issuances equity securities	$ 1,015	$ 3,382	$ 10,332