Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
CASH FLOWS PROVIDED BY (USED IN) OPERATING ACTIVITIES:
Net income	$ 43,227	$ 78,837
Adjustments to reconcile net income to cash provided by (used in) operating activities:
Depreciation and amortization	56,777	58,880
Stock-based compensation expense	14,689	12,442
Deferred income taxes	1,952	23,410
Goodwill impairment	8,409	0
Other, net	568	587
Changes in operating assets and liabilities:
Accounts receivable	207,994	(129,741)
Contract assets	(10,984)	(26,219)
Inventories	15,333	16,559
Prepaid expenses and other assets	11,687	436
Accounts payable	(185,175)	(85,037)
Accrued liabilities	(7,578)	77,148
Cash provided by operating activities	156,899	27,302
CASH FLOWS PROVIDED BY (USED IN) INVESTING ACTIVITIES:
Purchases of property, plant and equipment	(45,088)	(72,962)
Proceeds from sales of property, plant and equipment	632	1,139
Cash used in investing activities	(44,456)	(71,823)
CASH FLOWS PROVIDED BY (USED IN) FINANCING ACTIVITIES:
Repayments of long-term debt	24,986	0
Proceeds from revolving credit facility borrowings	1,909,000	2,242,225
Repayments of revolving credit facility borrowings	(1,259,000)	(2,207,225)
Debt issuance costs	0	(2,003)
Net proceeds from stock issuances	5,172	9,339
Repurchases of common stock	(82,033)	(12,010)
Cash provided by financing activities	548,153	30,326
Effect of exchange rate changes	(752)	161
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	659,844	(14,034)
Cash and cash equivalents at beginning of period	454,741	419,528
Cash and cash equivalents at end of period	1,114,585	405,494
Cash paid during the period for:
Interest, net of capitalized interest	8,407	13,589
Income taxes, net of refunds	13,371	13,237
Unpaid purchases of property, plant and equipment at the end of period	$ 9,377	$ 31,780