Business Acquisitions - Fair Values Assigned to the Assets and Liabilities Assumed (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Dec. 31, 2019	Jan. 02, 2021	Oct. 03, 2020
Asset (Liability)
Purchased goodwill		$ 230,623	$ 228,640	[1]
Supplemental information
Finite-Lived Intangible Asset Lives (Years)		14 years	14 years 1 month 6 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)
Advanced payments from customers	(3,203)
Accrued income taxes	(12)
Other accrued liabilities	(5,074)
Deferred income taxes	(11,239)
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
Customer lists
Supplemental information
Finite-Lived Intangible Asset Lives (Years)		15 years 8 months 12 days	15 years 8 months 12 days
Customer lists | R&D Acquisition
Asset (Liability)
Intangible assets	$ 24,364
Supplemental information
Finite-Lived Intangible Asset Lives (Years)	15 years
Trademarks and trade names
Supplemental information
Finite-Lived Intangible Asset Lives (Years)		17 years 7 months 6 days	17 years 7 months 6 days
Trademarks and trade names | R&D Acquisition
Asset (Liability)
Intangible assets	$ 8,546
Supplemental information
Finite-Lived Intangible Asset Lives (Years)	15 years
Technology | R&D Acquisition
Asset (Liability)
Intangible assets	$ 5,083
Supplemental information
Finite-Lived Intangible Asset Lives (Years)	10 years
Other intangible assets
Supplemental information
Finite-Lived Intangible Asset Lives (Years)		1 year 8 months 12 days	1 year 8 months 12 days
Other intangible assets | R&D Acquisition
Asset (Liability)
Intangible assets	$ 4,258
Supplemental information
Finite-Lived Intangible Asset Lives (Years)	1 year

[1] The Consolidated Balance Sheet as of October 3, 2020 has been derived from the audited consolidated financial statements at that date.The accompanying Notes to Consolidated Financial Statements (Unaudited) are an integral part of these consolidated financial statements.