Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
CASH FLOWS PROVIDED BY (USED IN) OPERATING ACTIVITIES:
Net income (loss)	$ (130,278)	$ 76,581
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation and amortization	59,502	58,249
Stock-based compensation expense	18,937	19,619
Deferred income taxes	165,098	13,744
Other, net	(674)	(244)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	22,967	1,119
Inventories	(70,171)	(73,338)
Prepaid expenses and other assets	(7,487)	2,827
Accounts payable	(34,467)	45,952
Accrued liabilities	10,696	(1,861)
Cash provided by operating activities	34,123	142,648
CASH FLOWS PROVIDED BY (USED IN) INVESTING ACTIVITIES:
Purchases of property, plant and equipment	(71,031)	(55,282)
Purchases of long-term investments	(2,019)	0
Proceeds from sales of property, plant and equipment	158	3,827
Cash used in investing activities	(72,892)	(51,455)
CASH FLOWS PROVIDED BY (USED IN) FINANCING ACTIVITIES:
Repayments of long-term debt	0	(40,000)
Proceeds from revolving credit facility borrowings	2,025,300	246,600
Repayments of revolving credit facility borrowings	(1,869,300)	(271,600)
Debt issuance costs	(1,701)	0
Net proceeds from stock issuances	3,439	22,691
Repurchases of common stock	(120,539)	(13,623)
Holdback payment for a prior business combination	0	(2,262)
Cash provided by (used in) financing activities	37,199	(58,194)
Effect of exchange rate changes	186	1,240
Increase (decrease) in cash and cash equivalents	(1,384)	34,239
Cash and cash equivalents at beginning of period	406,661	398,288
Cash and cash equivalents at end of period	405,277	432,527
Cash paid during the period for:
Interest, net of capitalized interest	13,780	9,070
Income taxes, net of refunds	15,369	9,799
Unpaid purchases of property, plant and equipment at the end of period	$ 28,139	$ 29,499