Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Income Statement [Abstract]
Net sales	$ 726,385	$ 618,832	$ 2,102,330	$ 1,858,200
Cost of sales	658,564	557,647	1,918,034	1,668,859
Gross profit	67,821	61,185	184,296	189,341
Selling and administrative expenses	35,375	31,716	102,978	93,398
Operating income	32,446	29,469	81,318	95,943
Other income (expense):
Interest expense	(2,910)	(3,294)	(10,182)	(9,830)
Interest income	1,068	1,299	4,049	3,555
Miscellaneous	(1,052)	(103)	(1,875)	1,147
Income before income taxes	29,552	27,371	73,310	90,815
Income tax expense	3,051	1,792	133,012	7,762
Net income (loss)	$ 26,501	$ 25,579	$ (59,702)	$ 83,053
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.81	$ 0.76	$ (1.79)	$ 2.47
Diluted (in dollars per share)	$ 0.79	$ 0.74	$ (1.79)	$ 2.40
Weighted average shares outstanding:
Basic (in shares)	32,796	33,669	33,300	33,636
Diluted (in shares)	33,651	34,568	33,300	34,585
Other comprehensive (loss) income:
Derivative instrument fair value adjustment	$ (5,023)	$ 2,991	$ (2,255)	$ 747
Foreign currency translation adjustments	(7,965)	6,367	(1,050)	(2,379)
Other comprehensive (loss) income	(12,988)	9,358	(3,305)	(1,632)
Total comprehensive income (loss)	$ 13,513	$ 34,937	$ (63,007)	$ 81,421