Business Acquisitions (Fair Values Assigned to the Assets and Liabilities Assumed) (Details) - USD ($) $ in Thousands				12 Months Ended
	Dec. 31, 2019	Aug. 05, 2019	Nov. 21, 2018	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Asset (Liability)
Purchased goodwill				$ 228,640	$ 429,039	$ 369,275
Supplemental information
Purchase price, net of cash acquired				$ 49,361	$ 151,956	$ 0
Finite-lived intangible asset lives (in Years)				14 years 1 month 6 days	14 years 4 months 24 days
R D Acquisition
Asset (Liability)
Accounts receivable	$ 13,557
Unbilled accounts receivable	6,325
Inventories	41
Prepaid expenses and other current assets	533
Property and equipment	1,185
Intangible assets	42,251
Other long-term assets	3,122
Purchased goodwill	35,887
Accounts payable	(12,592)
Accrued payroll and related costs	(2,193)
Advance payments from customers	(3,203)
Accrued income taxes	(1,113)
Other accrued liabilities	(5,074)
Deferred income taxes	(10,138)
Other long-term liabilities	(2,230)
Net assets acquired	66,358
Supplemental information
Consideration paid at closing	58,373
Estimated contingent consideration	16,903
Less: Cash acquired	(8,918)
Purchase price, net of cash acquired	66,358
Endevco
Asset (Liability)
Inventories		$ 11,649
Property and equipment		1,078
Intangible assets		25,700
Purchased goodwill		23,324
Deferred income taxes		6,579
Net assets acquired		68,330
Supplemental information
Consideration paid at closing		70,000
Post-closing purchase price adjustment		(1,670)
Purchase price, net of cash acquired		68,330
E2M Technologies B.V.
Asset (Liability)
Accounts receivable			$ 4,651
Unbilled accounts receivable			1,518
Inventories			11,063
Prepaid expenses and other current assets			123
Property and equipment			672
Intangible assets			43,989
Other long-term assets			60
Purchased goodwill			36,665
Accounts payable			(3,657)
Accrued payroll and related costs			(1,328)
Advance payments from customers			(4,315)
Accrued income taxes			(290)
Other accrued liabilities			(127)
Deferred income taxes			(10,477)
Net assets acquired			78,547
Supplemental information
Consideration paid at closing			79,772
Post-closing purchase price adjustment			515
Less: Cash acquired			(1,740)
Purchase price, net of cash acquired			78,547
Customer lists
Supplemental information
Finite-lived intangible asset lives (in Years)				15 years 8 months 12 days	15 years 7 months 6 days
Customer lists | R D Acquisition
Asset (Liability)
Intangible assets	$ 24,364
Supplemental information
Finite-lived intangible asset lives (in Years)	15 years
Customer lists | Endevco
Asset (Liability)
Intangible assets		$ 13,400
Supplemental information
Finite-lived intangible asset lives (in Years)		15 years
Customer lists | E2M Technologies B.V.
Asset (Liability)
Intangible assets			$ 21,652
Supplemental information
Finite-lived intangible asset lives (in Years)			15 years
Trademarks and trade names
Supplemental information
Finite-lived intangible asset lives (in Years)				17 years 7 months 6 days	18 years 4 months 24 days
Trademarks and trade names | R D Acquisition
Asset (Liability)
Intangible assets	$ 8,546
Supplemental information
Finite-lived intangible asset lives (in Years)	15 years
Trademarks and trade names | Endevco
Asset (Liability)
Intangible assets		$ 7,900
Supplemental information
Finite-lived intangible asset lives (in Years)		15 years
Trademarks and trade names | E2M Technologies B.V.
Asset (Liability)
Intangible assets			$ 5,926
Supplemental information
Finite-lived intangible asset lives (in Years)			15 years
Technology | R D Acquisition
Asset (Liability)
Intangible assets	$ 5,083
Supplemental information
Finite-lived intangible asset lives (in Years)	10 years
Technology | Endevco
Asset (Liability)
Intangible assets		$ 4,400
Supplemental information
Finite-lived intangible asset lives (in Years)		15 years
Technology | E2M Technologies B.V.
Asset (Liability)
Intangible assets			$ 12,650
Supplemental information
Finite-lived intangible asset lives (in Years)			15 years
Other intangible assets
Supplemental information
Finite-lived intangible asset lives (in Years)				1 year 8 months 12 days	4 years
Other intangible assets | R D Acquisition
Asset (Liability)
Intangible assets	$ 4,258
Supplemental information
Finite-lived intangible asset lives (in Years)	1 year
Other intangible assets | E2M Technologies B.V.
Asset (Liability)
Intangible assets			$ 3,761
Supplemental information
Finite-lived intangible asset lives (in Years)			4 years