Intangible Assets (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019	May 26, 2020	Dec. 31, 2019
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	$ 73,675,000		$ 73,675,000			$ 93,474,000
Accumulated Amortization	56,338,000		56,338,000			53,984,000
Net Carrying Value	17,337,000		17,337,000			39,490,000
Intangible asset impairment charges	19,571,000	$ 0	19,571,000	$ 0
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	17,337,000		17,337,000			39,490,000
Distribution networks
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	38,060,000		38,060,000			38,060,000
Accumulated Amortization	38,060,000		38,060,000			38,060,000
Net Carrying Value	0		0			0
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	0		0			0
Completed technologies
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	21,917,000		21,917,000			31,987,000
Accumulated Amortization	11,035,000		11,035,000			9,160,000
Net Carrying Value	10,882,000		10,882,000			22,827,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	10,882,000		10,882,000			22,827,000
Completed technologies | Sualab [Member]
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Intangible asset impairment charges	10,070,000
Customer relationships
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	10,578,000		10,578,000			14,407,000
Accumulated Amortization	6,795,000		6,795,000			6,402,000
Net Carrying Value	3,783,000		3,783,000			8,005,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	3,783,000		3,783,000			8,005,000
Customer relationships | Sualab [Member]
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Intangible asset impairment charges	3,382,000
Customer relationships | EnShape GmbH [Member]
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Accumulated Amortization					$ 228,000
Intangible asset impairment charges	219,000
Intangible assets acquired	0		0		$ 447,000
In-process technologies
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	2,300,000		2,300,000			8,200,000
Accumulated Amortization	0		0			0
Net Carrying Value	2,300,000		2,300,000			8,200,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	2,300,000		2,300,000			8,200,000
In-process technologies | Sualab [Member]
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Intangible asset impairment charges	5,900,000
Non-compete agreements
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	710,000		710,000			710,000
Accumulated Amortization	409,000		409,000			350,000
Net Carrying Value	301,000		301,000			360,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	301,000		301,000			360,000
Trademarks
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Gross Carrying Value	110,000		110,000			110,000
Accumulated Amortization	39,000		39,000			12,000
Net Carrying Value	71,000		71,000			98,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	71,000		71,000			$ 98,000
Indefinite-lived intangible asset excluding in-process technologies
Distribution Rights, Developed Technology Rights, Customer Contracts And Relationships, Other Intangible Assets, And Trademarks
Net Carrying Value	15,037,000		15,037,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal 2020	1,686,000		1,686,000
2021	3,272,000		3,272,000
2022	2,902,000		2,902,000
2023	2,211,000		2,211,000
2024	1,697,000		1,697,000
2025	1,374,000		1,374,000
Thereafter	1,895,000		1,895,000
Net Carrying Value	$ 15,037,000		$ 15,037,000