Valuation And Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Contract Reserves
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 60,914	$ 48,818	$ 46,314
Additions charged to cost and expenses	76,747	45,464	36,830
Deductions	66,885	35,714	34,241
Foreign exchange impact and other	1,636	2,346	(85)
Balance at end of year	72,412	60,914	48,818
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	5,402	4,959	4,351
Additions charged to cost and expenses	3,774	1,522	2,213
Deductions	3,144	891	1,468
Foreign exchange impact and other	281	(188)	(137)
Balance at end of year	6,313	5,402	4,959
Reserve for Inventory Valuation
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	134,185	125,316	108,539
Additions charged to cost and expenses	52,956	23,227	33,569
Deductions	35,747	12,716	15,540
Foreign exchange impact and other	1,917	(1,642)	(1,252)
Balance at end of year	153,311	134,185	125,316
Deferred Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	13,137	15,181	4,776
Additions charged to cost and expenses	2,003	274	10,499
Deductions	860	1,808	101
Foreign exchange impact and other	504	(510)	7
Balance at end of year	$ 14,784	$ 13,137	$ 15,181