Quarterly Financial Data (Unaudited) - Schedule Of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended								12 Months Ended
	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Quarterly Financial Data [Abstract]
Net sales	$ 810,195	$ 799,644	$ 789,051	$ 765,544	$ 771,178	$ 726,385	$ 698,651	$ 677,294	$ 3,164,434	$ 2,873,508	$ 2,528,052
Gross profit	77,789	71,030	70,636	72,383	73,304	67,821	52,952	63,523	291,838	257,600	255,855
Net income	36,831	$ 24,801	$ 24,758	22,226	$ 72,742	$ 26,501	12,290	(98,493)	108,616	13,040	112,062
Tax Reform Income Tax Expense (Benefit)				$ 7,000				$ 124,500		(38,600)
Restructuring costs									1,678	0	0
Restructuring costs, net of tax									1,500
Tax Expense (Benefit) of Undistributed Earnings of Foreign Subsidiaries									(10,500)
One-time employee bonus							$ 13,500			13,500
Additions (reductions) to valuation allowance	(3,600)								$ 1,900	$ (32,900)	$ 14,900
Other Tax Expense (Benefit)	$ 1,100
Tax Reform Income Tax Expense (Benefit), Per Share				$ 0.23	$ (1.24)			$ 3.59
Restructuring Costs, Per Share	$ 0.05
Tax Expense (Benefit) of Undistributed Earnings of Foreign Subsidiaries Per Share	(0.35)
Antidilutive Securities Excluded from Computation of Net Income, Per Share								$ 0.09
Antidilutive Securities Excluded from Computation of Diluted Earnings Per Share								1.1
One-time employee bonus, per share							$ 0.38
Earnings per share:
Basic (in dollars per share)	1.26	$ 0.83	$ 0.81	0.71	2.27	$ 0.81	0.37	$ (2.93)	$ 3.59	$ 0.40	$ 3.33
Diluted (in dollars per share)	$ 1.23	$ 0.81	$ 0.79	$ 0.69	$ 2.20	$ 0.79	$ 0.36	$ (2.93)	$ 3.50	$ 0.38	$ 3.24